AudelTM Carpenters and Builders Layout

AudelTM Carpenters and Builders Layout
TM
Audel
Carpenters and Builders
Layout, Foundation,
and Framing
All New 7th Edition
Mark Richard Miller
Rex Miller
TLFeBOOK
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10 9 8 7 6 5 4 3 2 1
Contents
Acknowledgments
xiii
About the Authors
xv
Introduction
Chapter 1
xvii
Locating a Building
Selection of Site
Staking Out
The Lines
Laying Out with Transit Instruments
Method of Diagonals
Points on Layout
Summary
Review Questions
1
1
1
1
2
3
5
6
7
Chapter 2
House Foundations
Slab-on-Grade
Crawl Space
Basement Construction
Pile Foundation
All-Weather Wood Foundation
Summary
Review Questions
9
9
15
21
22
22
23
24
Chapter 3
Concrete Forms and Hardware
Need for Strength
Bracing
Economy
Fastening and Hardware
Lumber for Forms
25
25
26
27
28
28
Practicality
Texture
Size and Spacing
Stripping Forms
Stripping Forms for Arches
31
34
34
34
38
v
vi Contents
Chapter 4
Special Forms
Prefabricated Forms
Summary
Review Questions
38
41
41
42
Site Equipment
Ladders
43
43
Setting Up a Ladder
Ladder Shoes
Ladder Accessories
Special Products
Ladder Safety
Scaffolding
Scaffolding Components
Scaffolding Safety Rules
Chapter 5
49
49
51
51
55
56
56
62
Summary
Review Questions
71
72
Concrete-Block Construction
Block Building Materials
73
74
Standard Masonry Units
Mortar
Block Building Methods
Basic Block-Laying
Laying Blocks at Corners
Building Walls Between Corners
Construction Methods
Walls
Building Interior Walls
Sills and Plates
Installation of Heating and Ventilating Ducts
Electrical Outlets
Insulation
Flashing
Floors
Summary
Review Questions
74
76
77
77
79
80
85
85
87
87
88
88
90
91
92
96
97
Contents vii
Chapter 6
Frames and Framing
Methods of Framing
Balloon-Frame Construction
Post-and-Beam Construction
Platform Frame Construction
Framing Terms
Sills
Girders
Joists
Subflooring
Headers and Trimmers
Walls and Partitions
Ledger Plates
Braces
Studs
Bridging
Rafters
Lumber Terms
Standard Sizes of Lumber
Framing Lumber
Chapter 7
99
99
99
99
99
100
100
102
103
103
104
104
106
106
106
107
107
107
107
108
Summary
Review Questions
109
109
Floors, Girders, and Sills
Girders
111
111
Construction of Girders
Placing Basement Girders
Sills
Types of Sills
Anchorage of Sill
Setting the Sills
Floor Framing
Connecting Joist to Sills and Girders
Bridging
Headers and Trimmers
Subflooring
111
111
114
115
116
116
117
117
118
118
121
viii Contents
Chapter 8
Summary
Review Questions
122
122
Constructing Walls and Partitions
Built-Up Corner Posts
Bracing
Preparing the Corner Posts and Studding
Erecting the Frame
Framing Around Openings
125
125
126
126
126
127
Headers
Size of Headers
Opening Sizes for Windows and Doors
128
128
129
Interior Partitions
Partitions Parallel to Joists
Partitions at Right Angles to Joists
Engineered Wood and I-Joist Open
Metal Web System
Labor and Material Costs Reduction
Chapter 9
130
130
131
131
132
Summary
Review Questions
137
137
Framing Roofs
Types of Roofs
Roof Construction
Rafters
Length of Rafter
Rafter Cuts
139
139
141
143
146
151
Common Rafter Cuts
Hip and Valley Rafter Cuts
Side Cuts of Hip and Valley Rafters
151
153
159
Backing of Hip Rafters
Jack Rafters
159
161
Shortest-Jack Method
Longest-Jack Method
Framing-Table Method
Jack-Rafter Cuts
162
162
163
163
Method of Tangents
164
Contents ix
Octagon Rafters
Trusses
Dormers
Summary
Review Questions
165
167
169
171
172
Chapter 10
Framing Chimneys and Fireplaces
Prefabricated Fireplaces
Contemporary Design
Summary
Review Questions
173
173
173
177
178
Chapter 11
Roofs and Roofing
Slope of Roofs
Selecting Roofing Materials
Roll Roofing
The Built-Up Roof
Wood Shingles
179
182
182
183
184
186
Hips
Valleys
190
190
Asphalt Shingles
Slate
Gutters and Downspouts
Summary
Review Questions
192
197
199
201
201
Chapter 12
Skylights
Residential Skylights
Skylight Maintenance
Tube-Type Skylights
Installation
Summary
Review Questions
203
205
207
213
213
216
216
Chapter 13
Cornice Details
Box Cornices
Closed Cornices
Wide Box Cornices
219
219
219
220
x Contents
Chapter 14
Chapter 15
Chapter 16
Open Cornices
Cornice Returns
Rake or Gable-End Finish
Summary
Review Questions
220
221
223
224
225
Doors
Manufactured Doors
227
227
Sash and Paneled Doors
Flush Doors
Louver Doors
227
227
229
Installing Mill-Built Doors
229
Door Frames
Doorjambs
Door Trim
230
230
232
Hanging Doors
Swinging Doors
Sliding Doors
Garage Doors
Summary
Review Questions
234
235
235
236
241
242
Windows
Window Framing
Double-Hung Windows
Hinged or Casement Windows
Gliding, Bow, Bay, and Awning Windows
Window Sash
243
244
244
245
245
246
Sash Installation
Sash Weights
Glazing Sash
247
247
248
Shutters
Summary
Review Questions
250
250
250
Siding
Fiberboard Sheathing
Wood Sheathing
251
251
251
Contents xi
Plywood Sheathing
Urethane and Fiberglass
Sheathing Paper
Wood Siding
Bevel Siding
Square-Edge Siding
Vertical Siding
Plywood Siding
Preservative Treatment
Wood Shingles and Shakes
252
254
254
255
256
257
257
258
259
259
Installation of Siding
259
Types of Nails
Corner Treatment
262
262
Metal Siding
Vinyl Siding
Summary
Review Questions
264
264
265
266
Appendix
267
Index
269
Acknowledgments
No book can be written without the aid of many people. It takes a
great number of individuals to put together the information available about any particular technical field into a book. Many firms
have contributed information, illustrations, and analysis to the
book.
The authors would like to thank every person involved for his
or her contributions. Following are some of the firms that supplied
technical information and illustrations.
American Plywood Association
Bilco Company
Billy Penn Gutters
National Forest Products Association
Owens-Corning
Portland Cement Association
Scholtz Homes, Inc.
Shetter-Kit, Inc.
Stanley Tools
Truswal Systems Corp.
Waco Scaffolding and Equipment
xiii
About the Authors
Mark Richard Miller finished his BS in New York and moved on
to Ball State University, where he earned a master’s degree, then
went to work in San Antonio. He taught high school and finished
his doctorate in College Station, Texas. He took a position at Texas
A&M University in Kingsville, Texas where he now teaches in the
Industrial Technology Department as a Professor and Department
Chairman. He has co-authored 11 books and contributed many
articles to technical magazines. His hobbies include refinishing a
1970 Plymouth Super Bird and a 1971 Road-runner.
Rex Miller was a Professor of Industrial Technology at The State
University of New York, College at Buffalo for more than 35 years.
He has taught at the technical school, high school, and college level
for more than 40 years. He is the author or co-author of more than
100 textbooks ranging from electronics through carpentry and sheet
metal work. He has contributed more than 50 magazine articles over
the years to technical publications. He is also the author of seven
Civil War regimental histories.
xv
Introduction
The Audel Carpenters and Builders Layout, Foundation, and Framing: All New Seventh Edition is the third of four volumes that cover
the fundamental tools, methods, and materials used in carpentry,
woodworking, and cabinetmaking.
This volume was written for anyone who wants (or needs) to
understand how the layout of a project or building is done; how the
foundation of a house is constructed; and how to frame a house. The
problems encountered here can make or ruin a house or any project.
Problems encountered by the carpenter, woodworker, cabinetmaker,
or do-it-yourselfer often need attention by someone familiar with the
requirements of the job well-done. Whether remodeling an existing
home or building a new one, the rewards of doing a good job are
great.
This book has been prepared for use as a practical guide in the selection, maintenance, installation, operation, and repair of wooden
structures. Carpenters and woodworkers (as well as cabinetmakers and new homeowners) should find this book (with its clear descriptions, illustrations, and simplified explanations) a ready source
of information for the many problems that they might encounter
while building, maintaining, or repairing houses and furniture. Both
professionals and do-it-yourselfers who want to gain knowledge of
woodworking and house building will benefit from the theoretical
and practical coverage of this book.
This is the third of a series of four books in the Carpenters and
Builders Library that was designed to provide you with a solid reference set of materials that can be useful both at home and in the
field. Other books in the series include the following:
r Audel Carpenters and Builders Tools, Steel Square, and Joinery: All New Seventh Edition
r Audel Carpenters and Builders Math, Plans, and Specifications: All New Seventh Edition
r Audel Carpenters and Builders Millwork, Power Tools, and
Painting: All New Seventh Edition
No book can be completed without the aid of many people. The
Acknowledgments mention some of those who contributed to making this the most current in design and technology available to the
carpenter. We trust you will enjoy using the book as much as we did
writing it.
xvii
Chapter 1
Locating a Building
The term layout means the process used to locate and fix the reference lines that define the position of the foundation and outside
walls of a building.
Selection of Site
Staking out (sometimes called a preliminary layout) is important.
The exact location of the building has to be properly selected. It
may be wise to dig a number of small, deep holes at various points.
The holes should extend to a depth a little below the bottom of the
basement.
If the holes extend down to its level, the groundwater (which is
sometimes present near the surface of the earth) will appear in the
bottom of the holes. This water will nearly always stand at the same
level in all the holes.
If possible, a house site should be located so that the bottom of
the basement is above the level of the groundwater. This may mean
locating the building at some elevated part of the lot or reducing
the depth of excavation. The availability of storm and sanitary sewers (and their depth) should have been previously investigated. The
distance of the building from the curb is usually stipulated in city
building ordinances, but this, too, should be known.
Staking Out
After the approximate location has been selected, the next step is to
lay out the building lines. The position of all corners of the building
must be marked in some way so that when the excavation is begun,
workers will know the exact boundaries of the basement walls (see
Figure 1-1). There are a couple of methods of laying out building
lines:
r With surveyor’s instrument
r By method of diagonals
The Lines
Several lines must be located at some time during construction,
and they should be carefully distinguished. They include the following:
r The line of excavation that is the outside line
r The face line of the basement wall inside the excavation line
1
2 Chapter 1
Figure 1-1 One way of laying out is with a hundred-foot tape.
Metal tape is standard, but this new fiberglass one works well
and cleans easily. (Courtesy of Stanley Tools.)
r In the case of masonry building, the ashlars line that indicates
the outside of the brick or stone walls
In a wooden structure, only the two outside lines must be located,
and often the line of the excavation is determined at the outset.
Laying Out with Transit Instruments
A transit is an instrument of precision, and the work of laying out
with this instrument is more accurate than with other methods. In
Figure 1-2, let ABCD be a building already erected. At a distance
from this (at right angle), building GHJK will be erected. Level
up the instrument at point E, making A and E the distance the
new building will be from points A and B. Make points B and
F the same length as points A and E. At this point, drive a stake
in the ground at point G, making points F and G the required
distance between the two buildings. Point H will be on the same
line as point G, making the distance between the two points as
required.
Place the transit over point G, and level it up. Focus the transit
telescope on point E or F and lock into position. Turn the horizontal
Locating a Building 3
K
D
C
A
B
E
F
G
J
H
Figure 1-2 Diagram illustrating method of laying out with
transit.
circle on the transit until one of the zeros exactly coincides with the
vernier zero. Loosen the clamp screw and turn the telescope and
vernier 90 degrees. This will locate point K , which will be at the
desired distance from point G. For detailed operation of the transit
(see Figure 1-3), see the manufacturer’s instructions or information
in the Audel Carpenters and Builders Math, Plans, and Specifications
book of this series. (See the Introduction for more details on this
series.) The level may be used in setting floor timbers, in aligning
posts, and in locating drains.
Method of Diagonals
All that is needed in this method are a line, stakes, and a steel tape
measure. Here, the right angle between the lines at the corners of a
rectangular building is found by calculating the length of the diagonal that forms the hypotenuse of a right-angle triangle. By applying
the following rule, the length of the diagonal (hypotenuse) is found.
Rule: The length of the hypotenuse of a right-angle triangle is
equal to the square root of the sum of the squares of each leg.
Thus, in a right-angle triangle ABC, the hypotenuse is AC,
AC = AB 2 + BC 2
Suppose, in Figure 1-4, ABCD represents the sides of a building
to be constructed, and it is required to lay out these lines to the
4 Chapter 1
Figure 1-3 Transit, used by builders, contractors, and others
for setting grades, batter boards, and various earth excavations.
dimensions given. Substitute the values given in the previous equation as follows:
√
AC = 302 + 402 = 900 + 1600 = 2500 = 50
To lay out the rectangle of Figure 1-4, first locate the 40-foot
line AB with stake pins. Attach the line for the second side to B,
and measure off this line the distance BC (30 feet), point C being
indicated by a knot. This distance must be accurately measured with
the line at the same tension as in A and B.
With the end of a steel tape fastened to stake pin A, adjust the
position of the tape and line BC until the 50-foot division on the
tape coincides with point C on the line. ABC will then be a right
angle, and point C will be properly located.
The lines for the other two sides of the rectangle are laid out in
a similar manner. After getting the positions for the corner stake
pins, erect batter boards and permanent lines (see Figure 1-5). A
simple procedure may be used in laying out the foundations for a
small rectangular building. Be sure that the opposite sides are equal
Locating a Building 5
C
30 FT LEG
D
90
°
SE
NU
TE AL)
O
N
P
HY IAGO
(D
A
40 FT LEG
B
Figure 1-4 Diagram illustrating how to find the length of the
diagonal in laying out lines of a rectangular building by using
the diagonals method.
and then measure both diagonals. No matter what this distance may
be, they will be equal if the building is square. No calculations are
necessary, and the method is precise.
Points on Layout
For ordinary residence work, a surveyor or the city engineer is employed to locate the lot lines. Once these lines are established, the
builder is able to locate the building lines by measurement.
A properly prepared set of plans will show both the contour of
the ground on which the building is to be erected and the new grade
line after the building is done. A convenient way of determining old
grade lines and establishing new ones is by means of a transit, or with
a Y level and a rod. Both instruments work on the same principle in
grade work. As a rule, masonry contractors have their own Y levels
and use them freely as walls are constructed, especially where levels
are to be maintained as the courses of material are placed.
In locating the grade of the earth around a building, stakes are
driven into the ground at frequent intervals and the amount of fill
indicated by the heights of these stakes. Grade levels are usually
established after the builders have finished, except that the mason
will have the grade indicated where the wall above the grade is to be
finished differently from the wall below grade. When a Y level is not
6 Chapter 1
D
d
B
A
30
IN
.
M M
BUILDING
LINES
a
b
S
30 IN.
F
L
EXCAVATION LINE
Figure 1-5 Permanent location of layout lines made by cutting
in batter boards (boards marked S, M, F, L). Slits L and M locate
the building lines. Approximately 30 inches away are lines F and
S, which are excavation lines.
available, a 12- or 14-foot straightedge and a common carpenter’s
level may be used, with stakes being driven to “lengthen” the level.
Summary
The term layout means the process of locating a fixed reference
line that will indicate the position of the foundation and walls of a
building.
A problem sometimes encountered is groundwater. It is sometimes present near the surface of the earth and will appear in the
bottoms of test holes, generally at the same level. If possible, a house
should be located so that the bottom of the basement floor is above
the level of the ground water.
After the location of the house has been selected, the next step is
to lay out or stake out the building lines. The position of all corners
of the house must be marked so that workers will know the exact
boundaries of the basement walls.
There are several ways to lay out a building site. Two of these
are with a surveyor’s instrument and with diagonal measurements.
When laying out a site, several lines must be located at some time
during construction. These lines are the line of excavation (which
is the outside line), the face line of the basement wall inside the
Locating a Building 7
excavation line, and, in the case of a masonry building, the ashlars
line (which indicates the outside of the brick or stone wall).
Review Questions
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
What is groundwater?
Name two methods used in laying out a building site.
What is the difference between laying out and staking out?
What is the line of excavation?
What is the ashlars line?
What is the advantage of using a fiberglass measuring tape in
the field?
How is a transit used in the layout of a basement?
What has to be done by the surveyor before the developer can
lay out houses?
When are grade levels established?
What are batter boards?
Chapter 2
House Foundations
The foundation is the part of a building that supports the load of the
superstructure. As generally understood, the term includes all walls,
piers, columns, pilasters, and other supports below the first-floor
framing.
Following are three general forms of foundation:
r Spread foundations (see Figure 2-1)
r Pile foundations
r Wood foundations
Spread foundations are the most popular type used. They receive
the weight of the superstructure and distribute the weight to a stable
soil base by means of individual footings. Pile foundations, on the
other hand, transmit the weight of the superstructure through a
weak soil to a more-stable base. Of relatively recent vintage is the
all-weather all-wood foundation, which is made of plywood soaked
with preservatives.
Following are three basic types of spread foundations:
r Slab-on-grade
r Crawl space
r Basement or full (see Figure 2-2)
Each foundation system is popular in certain geographic areas.
The slab-on-grade is popular in the South and Southwest. The crawl
space is popular throughout the nation. The basement is the most
popular in the Northern states.
Slab-on-Grade
There are three basic types of slab-on-grade. The most popular is
where the footing and slab are combined to form one integral unit.
Another type has the slab supported by the foundation wall, and
there is a type where the slab is independent of the footing and
foundation wall (see Figure 2-3).
The procedure for constructing a slab-on-grade would be as follows:
1. Clear the site—In most cases, no excavation is needed, but
some fill dirt may be needed. A tractor or bulldozer is usually
used to remove the unnecessary brush and trees. It can also be
used to spread the necessary fill.
9
10 Chapter 2
SPREAD
PILE
Figure 2-1 General forms for foundations.
SLAB-ON-GRADE
BASEMENT
CRAWL SPACE
Figure 2-2 Three types of spread foundations.
(A)
(B)
(C)
Figure 2-3 Three types of slab-on-grade foundations: (A) One
integral unit, (B) supported by foundation wall; and (C) independent.
House Foundations 11
2. Lay out the foundation—This is usually done with batter
board and strings. When the batter boards are attached to
the stakes, the lowest batter board should be 8 inches above
grade.
3. Place and brace the form boards—The forms are usually 2 ×
12 boards, 2 × 6 boards, or 2 × 4 boards, and are aligned
with the string. To keep the forms in proper position, they are
braced with 2 × 4 boards. One 2 × 4 is placed adjacent to
the form board and another is driven at an angle 3 feet from
the form board. A “kicker” is placed between the two 2 × 4
boards, to tie the two together. These braces are placed around
the perimeter of the building, 4 feet on center (see Figure 2-4).
FORM BOARD
Figure 2-4 Form
construction.
KICKER
STAKE
STAKE
4. Additional fill is brought in—The fill should be free of debris
or organic matter and should be screeded to within 8 inches
of the top of the forms. The fill should then be well tamped.
5. Footings are dug—The footings should be a minimum of 12
inches wide and should extend 6 inches into undisturbed soil.
The footings should also extend at least one foot below the
frost line (see Figure 2-5).
6. Place the base course—The base course is usually wash gravel
or crushed stone and is placed 4 inches thick. The base course
acts as a capillary stop for any moisture that might rise through
the soil.
7. Place the vapor barrier—The vapor barrier is a sheet of 0.006
polyethylene and acts as a secondary barrier against moisture
penetration.
12 Chapter 2
STAKE SPREADER
DOUBLEHEADED
NAILS
NAIL STAKE
WOOD
PLANKS
METAL
STRAP
SPREADER
Figure 2-5 Nail stake footing forms are faster than all-wood
forms, but require special equipment. High-carbon steel stakes
are driven into the ground. Wood planks are nailed to the
stakes. An adjustable metal stake spreader holds the top of
the stakes together.
8. Reinforce the slab—In most cases, the slab is reinforced with
6 × 6 No. 10-gauge wire mesh. To ensure that the wire mesh
is properly embedded, it is propped up or pulled up during the
concrete pour. Fiberglass strands added to the concrete mix
sometimes eliminate the need for wire mesh.
9. Reinforce the footings—The footings can be reinforced with
three or four deformed metal bars 18 to 20 feet in length. The
rods should not terminate at a corner. They should be bent to
project around it. At an intersection of two rods, there should
be an 18-inch overlap.
Once the forms are set and the slab bed completed, concrete is
brought in and placed in position. The concrete should be placed in
small piles and as near to its final location as possible. Small areas
of concrete should be worked. (In working large areas; the water
will supersede the concrete, causing inferior concrete.) Once the
concrete has been placed in the forms, it should be worked (poked
House Foundations 13
Figure 2-6 Hand tamping, or jitterbugging, concrete to place
large aggregate below the surface. The other worker (bent
over) is screeding with a long 2 × 4 to proper grade.
and tamped) around the reinforcing bars and into the corners of
the forms. If the concrete is not properly worked, air pockets or
honeycombs may appear.
After the concrete has been placed, it must be struck or screeded to
the proper grade. A long straightedge is usually used in the process.
It is moved back and forth in a saw-like motion until the concrete is
level with the forms. To place the large aggregate below the surface,
the concrete is hand tamped, or jitterbugged (see Figure 2-6). A
darby (a long flat tool for smoothing) is used immediately after the
jitterbug and is also used to embed the large aggregate (see Figure
2-7). To produce a round on the edge of the concrete slab, an edger is
used. The round keeps the concrete from chipping off and it increases
the aesthetic appeal of the slab (see Figure 2-8). After the water
sheen has left the surface of the slab, it is floated. Floating is used to
remove imperfections and to compact the surface of the concrete.
For a smooth and dense surface, the concrete is then troweled. It
can be troweled with a steel hand trowel, or it can be troweled with
a power trowel (see Figure 2-9).
14 Chapter 2
Figure 2-7 The darby being used after the jitterbug process.
Figure 2-8 Using an edger to round off the edges.
House Foundations 15
Figure 2-9 Using a power trowel.
Once the concrete has been finished, it should be cured. There
are three ways that the slab might be cured:
r Burlap coverings
r Sprinkling
r Ponding
Regardless of the technique used, the slab should be kept moist
at all times.
The photographs shown in Figures 2-10 through 2-17 were taken
where the soil permitted a shallow trench to serve as a footing for
the slab-on-grade.
Crawl Space
A crawl space foundation system can be constructed of an independent footing and concrete-block foundation wall, or the footing and
foundation wall can be constructed of concrete.
The footing should be constructed of concrete and should be
placed below the frost line. The projection of the footing past
the foundation wall should equal one-half the thickness of the
16 Chapter 2
Figure 2-10 Batter boards with string marking outer limits of
the slab.
Figure 2-11 Forms started using string as a guide.
House Foundations 17
Figure 2-12 Trenches for footings.
Figure 2-13 Tractor with trencher attached.
18 Chapter 2
Figure 2-14 The forms in place. Plumbing vents and drains set
in place.
Figure 2-15 Cables in place for the slab. Note trenching for
plumbing and for footings and reinforcement for the slab. Site
ready for concrete pouring.
House Foundations 19
Figure 2-16 Pouring the slab and leveling the concrete in the
forms.
Figure 2-17 Concrete slab poured. Rebar for porch ready for
concrete.
20 Chapter 2
foundation wall (see Figure 2-18). The thickness of the footing
should equal the width of the foundation wall. There are two basic
ways to form a footing for a crawl space:
X
WALL
KEY WAY
FOOTING
REBAR
Figure 2-18 Footing
construction. Keyways
secure the foundation wall
to the footing. This keeps
the wall from sliding
sideways from the pressure
of backfill and helps slow
down water seepage.
X
2X
r Dig a footing trench and place the concrete in the trench. To
maintain the proper elevation, grade stakes are placed in the
trench.
r Use form boards. If form boards are used, they should be properly erected and braced. In some cases, additional strength may
be needed, and reinforcement added.
The most convenient way to obtain concrete for a crawl space
foundation or footing (or, for that matter, any job where a fair
amount of material is required) is to have it delivered by truck.
The mix will be perfect, and it will be poured exactly where you are
ready for it with a minimum of effort on your part. Of course, this
method is more expensive than you mixing it. If you mix it yourself,
you can rent mixing equipment (such as a power mixer). A good,
strong concrete mix is three bags of sand to every bag of cement,
and enough water to keep the mix workable. On the other hand,
you can use four bags of concrete sand (that is, sand with rocks in
it) to every bag of cement. Forms are removed after the concrete
has hardened. Before laying the concrete masonry, the top of the
footings should be swept clean of dirt or loose material.
Regardless of whether the foundation wall is constructed of
placed concrete or concrete blocks, the top should be a minimum
of 18 inches above grade. This allows for proper ventilation, repair
work, and visual inspection.
House Foundations 21
Basement Construction
In basement construction, foundation walls should be built with
the utmost care and craftsmanship, because they are under great
pressure from water in the ground (see Figure 2-19).
PARGE
WASH GRAVEL
FOUNDATION
WALL
CONCRETE SLAB
DRAIN TILE
EXPANSION JOINT
REINFORCEMENT
FOOTING
Figure 2-19 Basement construction.
To properly damp-proof the basement (if such a situation exists),
a 4-inch drain tile can be placed at the base of the foundation wall.
The drain tile can be laid with open joints or it can have small openings along the top. The tile should be placed in a bed of wash gravel
or crushed stone and should drain into a dry streambed or storm
sewer. The outside of the wall should then be parged, or covered
with a mixture such as masonry cement, mopped with hot asphalt,
or covered with polyethylene. These techniques will keep moisture
from seeping through the foundation. For further protection, all
surface water should be directed away from the foundation system.
This can be done by ensuring that the downspout routes water away
from the wall and that the ground slopes away from it.
22 Chapter 2
Pile Foundation
Pile foundations are used to minimize and reduce settlement. There
are two classifications of piles (see Figure 2-20):
FRICTION
HARD STRATA
POINT-BEARING PILE
FRICTION PILE
Figure 2-20 Pile construction.
r Point-bearing piles transmit loads through weak soil to an area
that has a better bearing surface.
r Friction piles depend on the friction between the soil and the
pile to support the imposed load.
Many different kinds of materials are used for piles, but the most
common are concrete, timber, and steel.
All-Weather Wood Foundation
The wood foundation is composed of wood and plywood soaked
with preservatives. It was primarily developed so that a foundation could be installed in cold weather, when concrete cannot. The
wood foundation is not difficult to install, and it is faster to install
than a masonry foundation (see Figure 2-21). It can be used where
working with concrete is limited by short building seasons. Wood
foundations can be erected during freezing weather, or where there
is too short a period to construct a different type of foundation.
House Foundations 23
PRESSURE-TREATED WOOD
NOTE: SEE GENERAL NOTES FOR
PERMISSIBLE VARIATIONS.
FLASHING
PLYWOOD MAY OVERLAP FIELD
APPLIED TOP PLATE FOR SHEAR TRANSFER
8 IN. MIN.
FLOOR JOIST
FIELD APPLIED 2 ⫻ ___TOP PLATE
2 ⫻___TOP PLATE
CAULK
FINISH GRADE SLOPE 1/2 IN. PER FOOT
MIN. 6 FT FROM WALL
2 ⫻ ___ STUD WALL
WARM-SIDE
VAPOR BARRIER
INSULATION AS APPROPRIATE
1 ⫻ ___ OR PLYWOOD STRIP PROTECTING
TOP OF POLYETHYLENE FILM
WARM
SIDE
WARM-SIDE
VAPOR BARRIER
PLYWOOD
ASPHALT OR POLYETHYLENE FILM STRIPS
3 IN. OR 4 IN. CONCRETE SLAB
4 IN. GRAVEL OR CRUSHED STONE FILL
1 ⫻ ___ SCREED BOARD (OPTIONAL)
POLYETHYLENE FILM
___ ⫻ ___ BOTTOM PLATE
2 ⫻ ___ FOOTING PLATE
3/4 d
BACKFILL W/CRUSHED STONE
OR GRAVEL (SEE TEXT FOR HEIGHT)
OPTIONAL INTERIOR
FINISH
BELOW FROST LINE
d
2d
Figure 2-21 All-weather wood foundation (Courtesy of National Forest Products Assn.)
Summary
There are three general forms of foundations: spread foundations,
pile foundations, and wood foundations. Spread foundations are
the most popular type used. There are three basic types of these: the
slab-on-grade, the crawl space, and the basement.
The procedure for constructing a slab-on-grade would be to clear
the site, lay out the foundation, place and brace the form boards, add
fill, dig the footings, place the base course, place the vapor barrier,
reinforce the slab, and reinforce the footings.
24 Chapter 2
In basement construction, the foundation wall should be built
with the utmost care and craftsmanship to resist the assault of
ground water.
Review Questions
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
What are the two general forms of foundations?
What is a foundation?
Why is base course used?
How is a concrete slab cured?
How is a basement wall damp-proofed?
What does the word parged mean when working with concrete?
What is a darby?
Why are crawl spaces needed?
What are the two types of pile foundations?
Where would you use a wood foundation type of construction?
Chapter 3
Concrete Forms and Hardware
Since a concrete mixture is semi-fluid, it will take the shape of anything into which it is poured. Accordingly, molds or forms are necessary to hold the concrete to the required shape until it hardens.
Such forms or molds may be made of metal, lumber, or plywood.
Formwork may represent as much as one-third of the total cost of
a concrete structure, so the importance of the design and construction of this phase of a project cannot be overemphasized. The character of the structure, availability of equipment and form materials,
anticipated repeat use of the forms, and familiarity with methods of
construction influence design and planning of the formwork. Forms
must be designed with knowledge of the strength of the materials
and the loads to be carried. The ultimate shape, dimensions, and
surface finish must also be considered in the preliminary planning
phase.
Need for Strength
Forms for concrete structures must be tight, rigid, and strong. If
forms are not tight, there will be a loss of concrete that may result
in honeycombing, or a loss of water that causes sand streaking.
The forms must be braced well enough to stay in alignment, and
strong enough to hold the concrete. Keep in mind that concrete is
heavy. Though structural concrete can vary in weight from 60 to
300 pounds per cubic foot (lb/ft3 ), most structural slabs will use
concrete weighing about 150 lb/ft3 . This includes the weight of the
reinforcing. The form weights can vary from 4 to 15 pounds per
square foot.
Special care should be taken in bracing and tying down forms
such as those for retaining walls, in which the mass of concrete is
large at the bottom and tapers toward the top. In this type of construction, and in other types (such as the first pour for walls and
columns), the concrete tends to lift the form above its proper elevation. If the forms are to be used again, they must be designed
so that they can easily be removed and re-erected without damage. Most forms are made of wood, but steel forms are commonly
used for work involving large, unbroken surfaces such as retaining
walls, tunnels, pavements, curbs, and sidewalks (see Figure 3-1).
Steel forms for sidewalks, curbs, and pavements are especially advantageous, since they can be used many times.
Any concrete laid below ground level for support purposes (such
as foundations) must start below the freeze line. This will vary for
25
26 Chapter 3
Figure 3-1 Steel forms in place for a concrete slab.
different parts of the country, but is generally about 18 inches below
ground level. The length of time necessary to leave the forms in place
depends on the nature of the structure. For small-construction work
where the concrete bears external weight, the forms may be removed
as soon as the concrete will bear its own weight (that is, between
12 and 48 hours after the concrete has been poured). Where the
concrete must resist the pressure of the earth or water (as in retaining
walls or dams), the forms should be left in place until the concrete
has developed nearly its final strength. This may be as long as three
or four weeks if the weather is cold, or if anything else prevents
quick curing.
Bracing
The bracing of concrete formwork falls into a number of categories.
The braces that hold wall and column forms in position are usually
1-inch-thick boards or strips. Ordinarily such braces are not heavily
stressed because the lateral pressure of the concrete is contained by
wall ties and column clamps.
When it is not practical to use wall ties, the braces may be stressed
depending on the height of the wall being poured. Braces of this kind
are proportioned to support the wall forms against lateral forces.
Deep beam and girder forms often require external braces to prevent
the side forms from spreading.
Concrete Forms and Hardware 27
The lateral bracing that supports slab forms is also important.
Not only is it important in terms of safety, but also to prevent the
distortions that can occur when the shores are knocked out of position. Lateral bracing should be left in place until the concrete is
strong enough to support itself.
Economy
One concern of the builder, particularly today when costs of materials are so high, is economy. Forms for a concrete building, for
example, can cost more than either the concrete or reinforcing steel,
or, in some cases, more than both together. Hence, it is important
to seek out every possible cost-cutting move.
Saving on costs starts with the design of the building. The designer
must keep in mind the forms required for the building’s construction
and look to build in every possible economy. For example, it may be
possible to adjust the size of beams and columns so that they can be
formed with a combination of standard lumber or plywood-panel
sizes.
For example, in making a beam 10 or 12 inches wide, specially
ripped form boards are needed. On the other hand, surfaced 1inch × 6-inch (51/2-inch actual size) form boards will be just right
for an 11-inch-wide beam. Experience has shown that it is entirely
practical to design structures around relatively standardized beam
and column sizes for the sake of economy. When such procedures
are followed, any diminution of strength can be compensated for
by increasing the amount of reinforcing steel used—and money will
still be saved.
Another costly area to avoid is excessive design. It may just require a relatively small amount of concrete to add a certain look to a
structure, but the addition can be very expensive in terms of overall
cost.
Another economy may be found in the area of lumber lengths.
Long lengths can often be used without trimming. Studs need not be
cut off at the top or at a wall form, but can be used in random lengths
to avoid waste. Random-length wales can also be used. Where a wall
form is built in place, it does no harm if some boards extend beyond
the length of the form.
Paradoxically, some very good finish carpenters are not good at
form building because they spend a lot of time building the forms—
neatness and exact lengths or widths are not required. Because they
have overdone the form building, when it comes time to strip the
form, there may be many nails to remove, and the job may be much
more complicated.
28 Chapter 3
Fastening and Hardware
All sorts of devices are available to simplify the building and stripping of forms. The simplest is the double-headed nail (see Figure
3-2). The chief advantage of these nails is that they can be pulled
out easily because they are driven in only to the first head (see Figure 3-3). There are also many different varieties of column clamps,
adjustable shores, and screw jacks. Instead of wedges, screw jacks
are especially suitable when solid shores are used.
Figure 3-2 Double-headed scaffold, or framing, nail.
A number of wedges are usually required in form building (see
Figure 3-4). Wedges are used to hold form panels in place, as well
as to draw parts of forms into line, to adjust shores and braces.
Usually the carpenter makes the wedges on the job. A simple jig can
be rigged up on a table or a radial arm saw for cutting the wedges.
Form ties (available in many styles) are devices that support both
sides of wall forms against the lateral pressure of concrete. Used
properly, form ties practically eliminate external bracing and greatly
simplify the erection of wall forms.
A simple tie is merely a wire that extends through the form, the
ends of the wire double around a stud or wale on each side. Although
low in cost, simple wire ties are not entirely satisfactory because,
under pressure from the concrete, they cut into the wood members
and cause irregularities in the wall. The most satisfactory ties can
be partially or completely removed from the concrete after it has set
and hardened completely.
Lumber for Forms
Some concrete building construction is done by using wooden or
plywood forms. If kiln-dried lumber is used, it should be thoroughly
wet before concrete is placed. This is important because the lumber
will absorb water from the concrete, and if the forms are made
tight (as they should be), the swelling from absorption can cause
the forms to buckle or warp. Oiling or using special compounds
on the inside of forms (as detailed later in this chapter) before use
is recommended. This is especially true if the forms are to be used
repeatedly. It prevents absorption of water, assists in keeping the
forms in shape when not in use, and makes their removal from
around the concrete much easier.
Concrete Forms and Hardware 29
DOUBLE-HEADED
NAILS
DO NOT
NAIL HERE
Figure 3-3 Double-headed nails in action. Internal corners
make stripping easier.
Spruce or pine seems to be the best all-around material. One
or both woods can be obtained in most locations. Hemlock is
not usually desirable for concrete formwork because it is liable
to warp when exposed to concrete. One-inch lumber is normally
sufficient for a building form, and so is 5/8-inch, 1/2-inch, and 3/4inch plywood.
30 Chapter 3
BOLT ROD
ADJUSTABLE
COLLAPSIBLE
FORM LOCKS
LOOSE
WHEN WEDGES
ARE REMOVED
WEDGE
SLACK CUT
MUST NOT
BIND ENDWAY
PRACTICAL FORM FOR
LIFTING AND RESETTING
Figure 3-4 Wedges are very important in form building.
It should be noted that the actual building of forms is often a
complicated procedure, particularly when the form will be used in
building a large structure (such as tall walls or large floors). Such
things as the vertical pressure on the form when it is filled with
concrete, the lateral pressure, and the amount of deflection of the
form must all be considered. In essence, the form is a structure that
Concrete Forms and Hardware 31
BACKUP STAKE IN
SOFT GROUND
TOE
NAILS
Figure 3-5 Cellar wall form in firm ground.
takes a lot of stress, and, therefore, it must be built to withstand
that stress (see Figure 3-5).
Carpenters and builders must be familiar with the various methods and materials for building forms.
Practicality
If the job to be done is one on which speed is a prime factor (perhaps
because of labor costs), then it is important that the forms not be
unduly complicated or time-consuming. The design may be perfectly
acceptable from an engineering standpoint but poor in terms of
practicality.
One overall rule is that the components of the form be as large as
can be handled practically. When possible, use panels. Panels may
be made of suitably strong plywood, composed of boards all of the
same width, and fastened together at the back with cleats.
In making forms for columns, the forms may be built as openended boxes. Of course, the panels cannot be completely nailed
together until they are in place surrounding the column they are
reinforcing. It is usually considered good practice to leave a cleanout hold on one side of the bottom of column forms (see Figure 3-6).
Dirt, chips, and other debris are washed out of this hole, and then
it is closed.
Even when column forms are prepared carefully, though, minor
inaccuracies can occur. The form panels may swell, or may move
32 Chapter 3
CLOSURE
Figure 3-6 Column form with clean-out.
slightly when the concrete is poured. In a well-designed and wellbuilt form, such inaccuracies do not matter much because of the
allowances built into the forms. As mentioned earlier, forms are
wetted down thoroughly, thereby swelling them before use. It is
doubly important to do this because of the water-cement ratio. If
forms are dry, they will suck water from the concrete and change
its properties. A form with a wet surface also solves the problem of
wet concrete possibly honeycombing it.
When moldings are desired, they should be recessed into the
concrete (see Figure 3-7). It is very simple to nail triangular strips
or other molded shapes on the inside of a form (see Figure 3-8).
Projection moldings on concrete require a recess in the form that is
more difficult to make.
Horizontal recessed grooves should be beveled outward at the top
and bottom, or at least at the bottom. A form for a flat ledge cannot readily be filled out with poured concrete. Additionally, ledges
collect dirt and are likely to become unsightly.
Concrete Forms and Hardware 33
CONCRETE
CONCRETE
FORM
FORM
PREFERABLE
NOT DESIRABLE
Molded finish on concrete.
BAD DESIGN
BETTER
BEST
Figure 3-7 Horizontal grooves in concrete.
TRIANGULAR
MOLDING
PLYWOOD FORM
Figure 3-8 Column-form clamps.
LUMBER FORM
34 Chapter 3
If the placing of concrete can be timed to stop at a horizontal
groove, that groove will serve to conceal the horizontal construction joint. One point (often overlooked) is the use of a horizontal
construction joint as a ledge to support the forms for the next pour.
This is a simple way to hold forms in alignment.
Texture
With forms, a variety of ways may be used to enhance the texture
of the finished concrete. If a smooth finish is desired, forms may be
lined with hardboard, linoleum, or similar materials. Small-headed
nails should be used, and hammer marks should be avoided.
When a rough texture is wanted, rough form boards may be
arranged vertically and horizontally, in alternate panels. Other arrangements (such as diamonds, herringbones, or chevrons) can also
be used. As with almost anything else, the ingenious designer can
come up with many ways to get the job done.
Size and Spacing
The size and spacing of ties are governed by the pressure of the
concrete transmitted through the studs and wales to the ties. In
other words, a wale acts as a beam, and the ties as reactions. It
might be assumed, therefore, that large wales and correspondingly
large ties should be used. However, if size and spacing are limited by
economics, the tie-spacing limit is generally considered 36 inches,
with 27 to 30 inches preferred.
Many tie styles make it necessary to place spreaders in the forms
to keep the two sides of the form from being drawn together. Generally, spreaders should be removed so that they are not buried in
the concrete. Traditional spreaders are quite good and are readily
removed. Figure 3-9 shows how wood spreaders are placed and how
they are removed.
Several styles of spreaders can be combined with ties. Some of
these are made of wire nicked or weakened in such a way that the
tie may be broken off in the concrete within an inch or two from the
face of the form. After you withdraw the ties, the small holes that
remain are easily patched with mortar.
Stripping Forms
Unlike most structures, concrete forms are temporary. The forms
must later be removed or stripped (disassembled). Sometimes (for
example, in building a single home) forms are used only once and
then discarded. Nevertheless, in most cases, economy dictates that
a form be used and reused. Indeed, economical heavy construction
depends on reusing forms.
Concrete Forms and Hardware 35
WIRE THROUGH
OFF-CENTER HOLES
IN REMAINING
SPREADERS
TIE AT EACH PAIR
OF WALES
WIRE LOOPED AROUND
BOTTOM SPREADER
Figure 3-9 Wall form with spreaders.
Because forms are removable, the form designer has certain
restrictions. The designer must not only consider erection, but
also stripping. Thus, if a form is designed in such a way that
final-assembly nails are covered, it may be impossible to remove the
form without tearing it apart and possibly damaging the partially
cured concrete.
36 Chapter 3
WEDGES
STAKE
WEDGES USED IN PAIRS, THUS:
Figure 3-10 Soffit form for a small arch culvert.
A
B
A NAILED TO
B WITH
DOUBLE-HEAD
NAILS
Figure 3-11 Form for a small job.
WHEN NAILS ARE
WITHDRAWN, SHORES
ARE EASILY REMOVED
Concrete Forms and Hardware 37
ROCKS OR
SAND BAGS
Figure 3-12 Ways of
anchoring pedestal
footings.
Another bad design may be one in that the form is built so that
some of its members are encased in concrete and may be difficult to
remove. This may result in defective work. It is often advisable to
plan column forms so that they can be stripped without disturbing
the forms for the beams and girders.
For easier stripping, forms can be coated with special oils. These
are not always effective, however, and a number of coating compounds that work well have been developed over the years. These
compounds reduce the damage to concrete when stripping is difficult or perhaps carelessly done. The use of these coatings reduces
the importance of wetting formwork before placing concrete.
After stripping, forms should be carefully cleaned of all concrete
before they are altered and oiled for reuse.
38 Chapter 3
Figure 3-13 Cardboard box being used as a form in a concrete
floor-slab pour.
Stripping Forms for Arches
Forms for arches, culverts, and tunnels generally include hinges or
loose pieces that, when removed, release the form (see Figure 3-10).
Shores are often set on screw jacks or wedges to simplify their removal. Screw jacks are preferable to wedges because forms held in
jacks can be stripped with the least amount of hammering.
For small jobs where jacks are not available, shores that are almost self-releasing can be made. Two 2 × 6 boards are fastened
into a T-shaped section (see Figure 3-11) with double-headed nails.
When wedged into position, this assembly is a stiff column. After
the concrete hardens, the nails are drawn and the column becomes
two 2 × 6 boards, which are relatively easy to remove.
Special Forms
Forms are required for building concrete piers, pedestals, and foundations for industrial machinery. The job still involves carpentry,
Concrete Forms and Hardware 39
Figure 3-14 Prefabricated build-up panels used for concrete
forms.
because such forms differ only in detail from building forms, and
usually do not have to withstand the pressures that are built up in
deep wall or column forms.
Many piers are tapered upward from the footing. In these cases, it
is necessary to provide a resistance to uplift because the semi-liquid
concrete tends to float such forms. Once the problem is recognized,
it is easily solved. Two or more horizontal planks nailed or wired to
spikes will hold down most forms. Sandbags placed on ledges (see
Figure 3-12) are usually enough for smaller forms.
Some industrial forms are complicated and require cast-in-place
hold-down bolts for the machinery. If these bolts are not needed,
however, the work is greatly simplified. Foundations can also be
built with recesses into which bolts threaded on both ends can be
dropped through pipelined holes. The machine can be slid onto such
40 Chapter 3
Figure 3-15 Peg-and-wedge system used to connect and hold
prefabricated panels together.
Figure 3-16 Circular metal concrete form.
a foundation and jacked into position without too much difficulty.
If desired, the bolts can be grouted after they are in place.
Simple forms may be made by using a cardboard box filled with
wet sand, gravel, or dirt (see Figure 3-13). This can be used where
a slab is poured at grade level and there is a need for drains, toilets,
water closets, or showers to penetrate the slab.
Concrete Forms and Hardware 41
Figure 3-17 Spring-steel clamps.
Prefabricated Forms
In addition to lumber and plywood forms, there are a tremendous
variety of prefabricated forms (see Figure 3-14). These panels can be
made up in different widths and lengths. There is a peg-and-wedge
system to hold the panels together (see Figure 3-15).
A variety of hinged forms are available, as well as circular metal
ones (see Figure 3-16) and clamps (see Figure 3-17).
Summary
Concrete mixture is a semi-fluid that will take the shape of any form
into which it is poured. Forms are usually made of metal or wood.
Forms must be reasonably tight, rigid, and strong enough to sustain
the weight of the concrete.
Most concrete construction (such as building walls) is done by
using metal forms. Oiling or greasing the inside of the form before
use prevents absorption of water from the concrete, which could
buckle or warp the forms and weaken the concrete.
42 Chapter 3
Forms may also be prefabricated. Forms should be regarded as a
structure and built with economy and efficiency in mind.
Review Questions
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Why are concrete forms oiled or greased?
What are prefabricated forms?
Name two ways to economize when building forms.
How much does concrete weigh per cubic foot?
What does the term tie mean in formwork?
Why should economy be factored into a decision to make a
form or buy prefab?
A concrete mixture is ————.
How much does formwork cost in reference to the concrete
work?
What is a wale?
Where are wedges used in formwork?
Chapter 4
Site Equipment
The proper way to set up a ladder or scaffold is very important in
carpentry work. There are many applications for ladders. Being able
to safely handle a ladder is most important in any carpentry work.
There is always a roof to a building. It needs shingles and other
preparation that needs access to locations above ground level. Scaffolding is useful in painting and putting on the siding. If the house
is more than one story, you would probably include scaffolding to
finish up around the inside of the house where a skylight might be
mounted. For high ceilings, the scaffold is also needed for drywall
work and painting. Electricians and plumbers also use ladders and
scaffolds to perform their duties.
Ladders
The ladder is one of the most commonly used tools of the carpenter.
Ladders are made in a number of sizes and shapes, and they serve
a number of purposes in the construction business. You may use
a simple stepladder, or you may need complicated scaffolding for
support high above the ground or floor.
The single straight ladder consists of one section with two side
rails and several rungs made of round dowel rods in most instances.
Single ladders are available in 8- to 16-foot lengths and 18- to
20-foot lengths. The 8- to 16-foot size will have 13/8- to 23/4-inch
side rails, whereas the 18- to 20-foot size has side rails up to 3 inches
wide. These ladders are usually 16 inches wide both at the bottom
and at the top, and do not taper (see Figure 4-1).
Push-up ladders are convenient, light, and expandable. They are
made in 16-, 20-, 24-, and 28-foot lengths. The maximum working
length is 3 feet shorter than the specified length of the ladder. For
example, the 16-foot ladder has a working length of 13 feet, and the
28-foot ladder has a working length of 25 feet. These ladders can be
secured at a certain length by metal brackets hooked over the side
rails with an automatic catch (see Figure 4-2).
Most metal extension ladders are made of aluminum, which
makes them lighter than the same size of wooden ladder. The metal
extension ladder (see Figure 4-3) operates with a rope and pulley.
An automatic catch holds the extended ladder in place against the
rung of the bottom ladder. A 14-foot ladder of this type weighs
about 171/2 pounds. Metal extension ladders are available in total
extended lengths of 16, 20, 24, 28, 32, 36, and 40 feet. All of them
43
44 Chapter 4
Figure 4-1 Standard straight wooden ladder.
of Waco Scaffolding and Equipment)
16 IN.
Figure 4-2 Push-up wooden extension ladder.
19
3/ IN.
8
(Courtesy
Site Equipment 45
Figure 4-3 Aluminum flat-step extension ladder.
(Courtesy of Waco Scaffolding and Equipment)
must overlap at least 3 feet, except the 40-foot size, which requires
a 4-foot overlap to safely support the weight of a person.
Fiberglass ladders are available for those who must work near
electrical lines. It is important to choose a ladder that does not conduct current if you are going to work near electrical lines.
Magnesium ladders are available in both stepladder and
extension-ladder configurations. Magnesium has the advantage of
being a lightweight metal.
Stepladders, as previously mentioned, can be made of wood, aluminum, or magnesium. They may be made of pine (see Figure 4-4),
with flat front legs braced with metal brackets. A metal tie rod may
(or may not, depending on price) be inserted under each step to
hold the side rails steady and to prevent wobble as the ladder ages
46 Chapter 4
Figure 4-4 Southern pine commercial stepladder. (Courtesy of Waco Scaffolding and
Equipment)
with use. The dowels are usually made of hickory or ash, while the
side-rails and steps are made of pine. Hemlock is used for side rails
and steps in some wooden stepladders. The Occupational Safety
and Health Administration (OSHA) rates stepladders as commercial Type I, Type II, or Type III. It also rates them as industrial or
household types with a I, II, or III rating.
Light household stepladders have a duty rating of 225 pounds.
That means the step will hold 225 pounds at the center. In most
instances, the weight supported by the ladder will be no greater
than this. To be on the safe side, however, the center of the step
must be able to support four times that weight (in others words, 900
pounds). The ladder illustrated in Figure 4-5 has braced bottom and
top steps and uses vinyl shoes. These ladders come in heights of 3,
4, 5, and 6 feet.
The common trestle has no extension and resembles a triangle
(see Figure 4-6). The cross-members are 1-inch × 2-inch strips of
oak. Trestles are made in heights of 6, 8, 10, 12, 14, and 16 feet.
The distance between the side rails measures 15.25 inches inside.
A trestle weighs about 5 pounds per foot. Planks or platforms can
be suspended between two trestles to provide a runway. However,
this may not be high enough, so the trestle is also available with
extensions. The 6-foot trestle extends to 91/2 feet; the 8-foot size
goes to 131/2 feet; and the 10-foot size will extend to 161/2 feet.
The 12-foot ladder is will extend to 201/2 feet. This one is a little
heavier, since it has an extension as part of the package. It will weigh
Site Equipment 47
Pail shelf with
rag rail and tool
holders.
Figure 4-5 Aluminum stepladder with vinyl shoes. (Courtesy of Waco
Scaffolding and Equipment)
Figure 4-6 Common trestle.
about 7 pounds per foot (see Figure 4-7). The extensions can be
placed so that the platform can be mounted between two trestles to
support one or two people. The strength of the platform is important
for safety reasons. Figure 4-8 shows what can happen when two
stepladders are used to support an ordinary plank. The ladders with
the Stinson plank provide a more secure platform that does not
sag. A sagging plank can cause a person to become unbalanced and
fall.
The New York extension trestle has a special locking device that
holds the middle ladder in such a way as to eliminate all wobble.
This device is so designed that any weight applied on the ladder will
48 Chapter 4
Figure 4-7 Heavy-duty extension trestle.
(Courtesy of Waco Scaffolding and Equipment)
STINSON
PLANK
ORDINARY
PLANK
Figure 4-8 The plank makes a difference. (Courtesy of Waco Scaffolding and
Equipment)
increase the grip on the lock. The middle ladder has a rung spacing
of 8 inches to permit adjustment at the upper levels. This is the most
expensive of the trestle ladders. It comes in lengths of 6, 8, 10, 12,
14, and 16 feet. The 6-foot ladder extends to 10 feet; the 8-foot to
14 feet; the 10-foot to 18 feet; the 12-foot to 22 feet; the 14-foot to
26 feet; and the 16-foot to 30 feet.
Figure 4-9 shows how a fiberglass trestle ladder is used to support
a scaffold plank.
Site Equipment 49
Figure 4-9 Fiberglass extension
trestle ladder. (Courtesy of Waco Scaffolding and
Equipment)
Setting Up a Ladder
Raising a ladder can be a two-person job. In fact, a heavier ladder
should have two workers on it. However, if you have a single ladder
that’s not too heavy, you can place the end of the ladder against
the house or some obstruction and walk it up one rung at a time
(see Figure 4-10). Keep in mind that the top of the ladder should
be placed against the house. The bottom of the ladder will have a
distance from the house of one-fourth the length of the ladder. Some
safety tips will be given later in this chapter as to what angles to use,
how much overlap to allow for extension ladders, and how to make
sure the ladder does not slip after it has been placed. The main thing
is to get the right ladder for the job at hand. A ladder too long can
cause as much trouble as one that is too short. The strength of the
ladder is also important, since it must support one, two, or more
people as well as building materials.
Ladder Shoes
To keep the ladder from slipping while you are on it, anchor the
bottoms of the side rails with ladder shoes. These shoes fit over the
ends of the side rails. A number of types are available. The rubber
boot keeps the ladder from slipping as a person climbs. The rubber
is nonconductive and useful in corrosive atmospheres (see Figure
4-11).
50 Chapter 4
Figure 4-10 Walking a ladder up.
Figure 4-11 Rubber-boot ladder shoe.
(Courtesy
of Waco Scaffolding and Equipment)
The universal-safety ladder shoe tilts and provides protection on
all kinds of surfaces. It is a dual-purpose shoe, as it is equipped with
steel spikes and with suction-grip composition treads (see Figure
4-12).
The steel-spur wheel shoe (see Figure 4-13) has steel points. When
it becomes worn, the wheel can be turned to expose new points. This
shoe is used extensively by public utility companies and industries.
Stepladder shoes (see Figure 4-14) can be added by inserting a
bolt through the side rails or legs of the ladder. They can be easily
Site Equipment 51
Figure 4-12 Universal-safety ladder shoe.
(Courtesy of Waco Scaffolding and Equipment)
Figure 4-13 Steel-spur wheel shoe.
(Courtesy of Waco Scaf-
folding and Equipment)
Figure 4-14 Stepladder shoes.
(Courtesy of
Waco Scaffolding and Equipment)
adjusted to fit the angle of the terrain on which the ladder is being
used. Composition soles are placed on the bottom of the shoes to
prevent slipping.
Ladder Accessories
Ladders, like everything else these days, have accessories that can
be added to make them adaptable to almost any purpose. Figure
4-15 shows several ladder accessories: a house pad can be added to
prevent sliding along a wall; a pole strap can be added to make the
ladder secure against a pole when necessary. Other safety devices
can be ordered to fit any ladder.
Special Products
The aluminum ladder jack comes in handy when you need to put
a plank between two ladders to serve as a platform. The aluminum
ladder jack (see Figure 4-16) has an adjustable arm with a positive lock. Adjustments are every inch, so it can be used on either
side of the ladder. It can be installed on ladders with roof hooks,
enabling the user to work on the roof or the face of a dormer. It
52 Chapter 4
HOUSE PAD
ADJUSTABLE
POLE STRAP
45 IN.
OPTIONAL
PAIL SHELF
STABILIZER
POLE LASH
Figure 4-15 Ladder accessories. (Courtesy of Waco Scaffolding and Equipment)
accommodates forms up to 18 inches wide, but folds to 6 inches
deep for storage.
The side-rail ladder jack (see Figure 4-17) has a four-point suspension that engages the side rails of the ladder. It fits ladders with
round or D-shaped rungs. It can be used on either side of the ladder,
so 12-inch planks fit over the jack. A larger type will take 20-inchwide aluminum planks, but it has oversized hooks that span double
rails.
Site Equipment 53
Figure 4-16 Ladder jack. (Courtesy of Waco Scaffolding and Equipment)
Figure 4-17 Side-rail ladder jack.
(Courtesy of Waco Scaffolding and Equipment)
The ladder hook comes in handy for a number of jobs. It attaches
to the ladder quickly and fits over an edge or the top of a wall. The
screw device on the spine clamps over one rung of the ladder, and
the bottom curve fits against a lower rung (see Figure 4-18).
Telescoping extension planks are light, durable, and convenient
for light interior use by one person (see Figure 4-19). They come in
two and three sections only. The outside width is 12 inches, and the
length can be 6, 8, or 10 feet.
A truck caddy rack comes in handy for transporting ladders
from the work site to storage and back to the work site. The caddy
(see Figure 4-20) fits on a pickup truck. The rack has only four basic
Figure 4-18 Ladder hook.
(Courtesy of
Waco Scaffolding and Equipment)
Figure 4-19 Telescoping extension planks. (Courtesy of Waco Scaffolding and
Equipment)
Figure 4-20 Truck caddy rack for ladders and planks.
Waco Scaffolding and Equipment)
54
(Courtesy of
Site Equipment 55
parts and bolts together easily. This caddy allows you to secure the
ladders safely.
Ladder Safety
Ladders are only as safe as the user makes them. You can make them
accident-proof with a little effort. The best bet is to use ladders that
meet all local code requirements. OSHA has established standards
for ladders, which will be marked on the side rail so that you know
into which classification your ladder fits. Wooden ladders should
not be painted, but you can coat them with varnish or another clear
finish. The reason for not painting a ladder is that you must be able
to inspect the wood for cracks and defects in the grain.
Keep the screws and bolts tightened so that the braces and all
other parts of the ladder remain in top condition at all times. Remember, your life may depend on the condition of the ladder.
Make sure you use the proper ladder for the job. The ladder
should extend at least 3 feet above the roofline if you plan to use it
to climb onto the roof. This extension will give you something to
grasp as you get on and off the ladder.
The proper anchoring of the ladder is very important. It isn’t a
nice feeling to get on the ladder and have it start to rock back and
forth or slide along the wall. The correct angle for the ladder is
75 degrees with the ground. The space from the foot of the ladder
to the wall should be one-fourth the length of the ladder.
Of course, you should face the ladder as you climb up and down.
Don’t lean too far to the left or right while working on the ladder.
Keep one hand on the side rail and the other hand on the rungs as
you climb or descend the ladder. If you are carrying paint or tools
in one hand, use your other hand to hold on to the side rail as you
climb. Put your feet firmly on the rungs, and make sure your shoes
and the rungs are free from grease, mud, and other substances. Keep
your feet and the ladder clean for safety’s sake. Just keep one hand
on the ladder at all times.
Make sure the ladder is properly shimmed so it fits snugly into
the ground. Ladder shoes can be helpful in most instances. You can
adjust them to fit any angle, and they have nonskid material on the
soles. In some cases, you may need to place a board under the ladder
to level it before climbing.
Keep in mind that it takes two people to get longer extension
ladders in place. Don’t try to place a long ladder by yourself. Ask
for help. If you do it alone, you risk breaking windows and straining
muscles. However, do not allow two people to stand on a ladder at
the same time.
56 Chapter 4
Scaffolding
Scaffolding allows you access to high places quickly and efficiently.
It can be movable, or it can be held in place with permanent brackets or nailed to boards. In this chapter, we cover primarily scaffolding that can be assembled and torn down for easy storage or
transport.
A number of features should be examined in the interest of safety.
State and federal regulations apply to all scaffolding, so the manufacturer is aware of the limitations of a specific arrangement. Follow
the manufacturer’s recommendations for a safe tower or support
platform.
In this chapter we will take a quick look at scaffolding and its
basic components. As you view the illustrations, you will begin to
see what scaffolding is, how it is used, and what special advantages
this type of construction offers.
Scaffolding Components
Scaffolding has two basic parts: end frames and cross braces (see
Figure 4-21). Several basic sections can be joined together vertically
to form a tower, or they can be joined side-by-side to make a run
(Figure 4-22). Alternatively, you can use a combination of the tower
and the run. A device called the Speed lock secures braces to end
frames (see Figure 4-23). It will hold one brace (which is necessary
in towers) or two (which are needed in runs of scaffolding).
The coupling pin (see Figure 4-24) is used to stack one frame
on top of another when you are building a vertical scaffold. The
coupling pin is designed to permit building up frames one leg at a
time. When building rolling towers, or when uplift of frames could
occur, frames should be locked together with toggle pins or with
bolts and nuts.
End frames for sectional scaffolding come in two basic widths:
the standard 5-foot-wide end frames in various shapes, and the
275/8-inch-wide narrow frames (see Figure 4-25). The height selected depends on trade or union preferences and the nature of the
work. The 6-foot, 7-inch-high frames are practical for higher scaffolds, because fewer units need to be assembled or dismantled for
a given height and because their higher overhead clearance makes
them easy to walk through. Extension frames and end frames allow
you to build scaffolding to any convenient height and to tier or contour it to suit ceiling contours and other projections. On exterior
walls, the walk-through frame is frequently used. When combined
with side brackets, it allows maximum clearance and freedom of
movement.
(A)
(B)
(C)
Figure 4-21 (A) End frames and (B) cross braces comprise (C)
scaffolding. (Courtesy of Waco Scaffolding and Equipment)
UP as in towers . . .
or OUT as in runs . . .
or BOTH
Figure 4-22 Putting end frames and cross braces together. (Courtesy of Waco Scaffolding and Equipment)
58 Chapter 4
(A) Lift Speedlock. Retaining pin allows it to be
raised far enough to permit attachment of brace.
(C)
(B) Brace is attached by slipping end over the
Speedlock stud. Release Speedlock and brace
is secured in place.
Figure 4-23 Speed lock secures braces to the end frames. (Courtesy of Waco Scaffolding and Equipment)
Note the combination walk-through frame in Figure 4-26. The
guardrail post slips over the top of the frame, and is attached to provide a safe working area on top of the frame. Figure 4-27 shows the
guardrail and toe-board assemblies used with standard scaffolding.
Guardrail post, guardrails, and toe-board assemblies should be used
on all types of scaffolding installations (both rolling and stationary)
according to applicable federal and state safety regulations. Occasionally, guardrails must be provided for unusual spacing. They can
Site Equipment 59
COUPLING PIN
FRAME LEG
SPRING CONNECTOR
When building rolling towers, or
when uplift of frames could occur,
frames should be locked together
with toggle pins, or with bolts and
nuts.
TOGGLE PIN
Figure 4-24 A coupling pin is used to stack one frame on top
of another. (Courtesy of Waco Scaffolding and Equipment)
be held by using a nailing plate that goes around a guard post and
to that timber can be nailed.
Cross-braces come in two types and various lengths. There are
single-hole braces and double-hole braces. The length of the braces
will depend on the length of the planks to be used, the weight the
scaffold must support, and the area to be covered. Double-hole
braces can be used on different-sized frames to obtain the same
frame spacing (see Figure 4-28). Straddle braces are available in
lengths of 7 or 10 feet. These permit scaffolding to be erected over
obstructions. The purpose is to straddle furniture, machinery, materials, or whatever is in the way. They will allow worker traffic under
the scaffolding (see Figure 4-29).
After determining how high you will go with the scaffold and
the preferred height of the frames, select the number of frames and
braces needed for the length of the run by referring to Table 4-1.
Figure 4-30 shows the hoist standard. It can be pinned to the
top of any frame. It is an easy way to provide an easy method for
moving up to 100 pounds of material to the top of the scaffold. The
hoist standard is slipped over the coupling pin and pinned to the leg.
The head is complete with a 12-inch well wheel that holds rope up
to 1-inch thick. This head swivels so that materials may be swung
over the scaffold platforms.
60 Chapter 4
(A) Three Styles of Interior Bracing.
No interior ledger
Interior ledger, one side
Interior ledger, two sides
(B) Walk-Through Frames.
29 IN.
6 FT 7 IN.
6 FT 0 IN.
6 FT 7 IN.
16 IN. 14 IN. 16 IN.
5 FT 0 IN.
45 IN.
6 FT 0 IN.
6 FT 7 IN.
6 FT 0 IN.
22 IN.
21 IN.
19 IN.19 IN. 17 IN.
5 FT 0 IN.
13 IN.
5 FT 0 IN.
Note: All vertical dimensions indicate leg height. Leg extend 1 inch above ledger on all frames.
27 5/8 IN.
(C) Narrow Frames.
6 FT 7 IN.
Figure 4-25 Different sizes and shapes of frames.
6 FT 7 IN.
27 5/8 IN.
5 FT 1 IN.
27 5/8 IN.
(Courtesy of Waco
Scaffolding and Equipment)
Figure 4-31 shows a pair of platform supports bolted to a piece
of plywood to make a convenient platform for a rolling tower.
Figure 4-32 shows a tower of the rolling type used by painters.
Rolling towers can be made from standard end frames fitted with
horizontal braces and casters. The casters (see Figure 4-33) are
available in 5- and 8-inch diameters and are equipped with a brake
permitting the user to lock the wheel in position. When assembling
Site Equipment 61
Figure 4-26 Combination walkthrough frame. (Courtesy of Waco Scaffolding
and Equipment)
Figure 4-27 Guard rail. (Courtesy of Waco Scaffolding and Equipment)
62 Chapter 4
Figure 4-28 Cross braces. (Courtesy of Waco Scaffolding and Equipment)
Figure 4-29 Straddle braces. (Courtesy of Waco Scaffolding and Equipment)
a rolling tower, always use horizontal braces on the frame section.
This prevents the tower from racking (getting out of square). On
rolling towers, horizontal braces must be used at the bottom and at
every 20-foot height measured from the rolling surface (see Figure
4-34).
Scaffolding safety rules are reprinted here with the permission of
the Scaffolding and Shoring Institute.
Scaffolding Safety Rules
Following are some commonsense rules, as recommended by the
Scaffolding and Shoring Institute, designed to promote safety in the
use of steel scaffolding. These rules are illustrative and suggestive
Site Equipment 63
WHEEL
HOIST
STANDARD
Figure 4-30 Hoist standard.
(Courtesy of
Waco Scaffolding and Equipment)
Figure 4-31 Platform supports bolted to a piece of plywood.
(Courtesy of Waco Scaffolding and Equipment)
64 Chapter 4
Table 4-1 Scaffolding Selection∗
4-Foot
Frames
41/2-Foot
Frames
5-Foot
Frames
61/2-Foot
Frames
1
4 feet
41/2 feet
5 feet
61/2 feet
2
8 feet
9 feet
10 feet
13 feet
3
12 feet
131/2 feet
15 feet
191/2 feet
4
16 feet
18 feet
20 feet
26 feet
5
20 feet
221/2 feet
25 feet
321/2 feet
6
24 feet
27 feet
30 feet
39 feet
7
28 feet
311/2 feet
35 feet
451/2 feet
8
32 feet
36 feet
40 feet
52 feet
9
36 feet
401/2 feet
45 feet
581/2 feet
10
40 feet
45 feet
50 feet
65 feet
11
44 feet
491/2 feet
55 feet
711/2 feet
12
48 feet
54 feet
60 feet
78 feet
13
52 feet
581/2 feet
65 feet
841/2 feet
14
56 feet
63 feet
70 feet
91 feet
No. of
Frames High
Note: Allowable plank span and scaffold loading must be in accordance with
federal and state regulations.
∗ Seven-foot spacing assumed. Bold figures indicate number of braces.
only, and are intended to deal only with some of the many practices
and conditions encountered in the use of scaffolding. These rules do
not purport to be all-inclusive or to supplant or replace other additional safety and precautionary measures to cover usual or unusual
conditions. They are not intended to conflict with or supersede any
state, local, or federal statute or regulation; reference to such specific provisions should be made by the user. Reprinting of these rules
does not imply approval by the Institute or indicate membership in
the Institute.
Site Equipment 65
Table 4-1 (continued )
7-Foot
Frames
14-Foot
Frames
21-Foot
Frames
28-Foot
Frames
35-Foot
Frames
42-Foot
Frames
2
2
4
4
6
6
8
8
10
10
12
12
14
14
16
16
18
18
20
20
22
22
24
24
26
26
28
28
3
4
6
8
9
12
12
16
15
20
18
24
21
28
24
32
26
36
30
40
33
44
36
48
39
52
42
56
4
6
8
12
12
18
16
24
20
30
24
36
28
42
32
48
36
54
40
60
44
66
48
72
52
78
56
84
5
8
10
16
15
24
20
32
25
40
30
48
35
56
40
64
45
72
50
80
55
88
60
96
65
104
70
112
6
10
12
20
18
30
24
40
30
50
36
60
42
70
48
80
54
90
60
100
66
110
72
120
78
130
84
140
7
12
14
24
21
36
28
48
35
60
42
72
49
84
56
96
63
108
70
120
77
132
84
144
91
156
98
168
r Post these scaffolding safety rules in a conspicuous place and
be sure that all persons who erect, dismantle, or use scaffolding
are aware of them.
r Follow all state, local, and federal codes, ordinances, and regulations as they pertain to scaffolding.
r Inspect all equipment before using. Never use any equipment
that is damaged or deteriorated in any way.
r Keep all equipment in good repair. Avoid using rusted equipment (the strength of rusted equipment is not known).
r Inspect erected scaffolds regularly. Be sure that they are maintained in safe condition.
66 Chapter 4
Table 4-1 Scaffolding Selection∗ (continued )
No. of Frames
High
1
2
3
4
5
6
7
8
9
10
11
12
13
14
∗ Seven-foot
49-Foot
Frames
56-Foot
Frames
63-Foot
Frames
70-Foot
Frames
77-Foot
Frames
84-Foot
Frames
8
14
16
28
24
42
32
56
40
70
48
84
56
98
64
112
72
126
80
140
88
154
96
168
104
182
112
196
9
16
18
32
27
48
36
64
45
80
54
96
63
112
72
128
81
144
90
160
99
176
108
192
117
208
126
224
10
18
20
36
30
54
40
72
50
90
60
108
70
126
80
144
90
162
100
180
110
198
120
216
130
234
140
252
11
20
22
40
33
60
44
80
55
100
66
120
77
140
88
160
99
180
110
200
121
220
132
240
143
260
154
280
12
22
24
44
36
66
48
88
60
110
72
132
84
154
96
176
108
198
120
220
132
242
144
264
156
286
168
308
13
24
26
48
39
72
52
96
65
120
78
144
91
168
104
192
117
216
130
240
143
264
156
288
169
312
182
336
spacing assumed. Bold figures indicate number of braces.
r Consult your scaffolding supplier when in doubt. Scaffolding
is the supplier’s business. Never take chances.
r Provide adequate sills for scaffold posts, and use base plates.
r Use adjusting screws instead of blocking to adjust to uneven
grade conditions.
r Plumb and level all scaffolds as the erection proceeds. Do not
force braces to fit. Level the scaffold until proper fit can be
made easily.
r Fasten all braces securely.
Site Equipment 67
Table 4-1 (continued )
91-Foot
Frames
98-Foot
Frames
105-Foot
Frames
112-Foot
Frames
119-Foot
Frames
126-Foot
Frames
133-Foot
Frames
14
26
28
52
42
78
56
104
70
130
84
156
98
182
112
208
126
234
140
260
154
286
168
312
182
338
196
364
15
28
30
56
45
84
60
112
75
140
90
168
105
196
120
224
135
252
150
280
165
308
180
336
195
364
210
392
16
30
32
60
48
90
64
120
80
150
96
180
112
210
128
240
144
270
160
300
176
330
192
360
208
390
224
420
17
32
34
64
51
96
68
128
85
160
102
192
119
224
136
256
153
288
170
320
187
352
204
384
221
416
238
448
18
34
36
68
54
102
72
136
90
170
108
204
126
238
144
272
162
306
180
340
198
374
216
408
234
442
252
476
19
36
38
72
57
108
76
144
95
180
114
216
133
252
152
288
171
324
190
360
209
396
228
432
247
468
266
504
20
38
40
76
60
114
80
152
100
190
120
228
140
266
160
304
180
342
200
380
220
414
240
456
260
496
280
532
r Do not climb cross braces. An access (climbing) ladder, access
steps, a frame that is designed to be climbed, or equivalent safe
access to the scaffold shall be used.
r On wall scaffolds place and maintain anchors securely between structure and scaffold at least every 30 feet of length
and 25 feet of height.
r When scaffolds are to be partially or fully enclosed, specific
precautions must be taken to ensure frequency and adequacy
of ties attaching the scaffolding to the building because of
increased load conditions resulting from effects of wind and
68 Chapter 4
TOE BOARD
GUARDRAIL POST
GUARDRAILS
FRAME
TOGGLE PIN
CROSS BRACE
SCREWJACK
WITH SOCKET
HORIZONTAL BRACE
CASTER
Figure 4-32 Rolling scaffolds. (Courtesy of Waco Scaffolding and Equipment)
Consult codes for allowable
extension.
Site Equipment 69
(A) Casters specially designed for use with rolling
scaffolds. They are available in 5-inch and 8-inch
diameters and are equipped with a brake
permitting the user to lock the wheel in position.
(B) Casters wheels can be used with this
adjustment screw, which allows adjustment
of tower height.
Figure 4-33 Caster and adjustment screw for casters. (Courtesy of
Waco Scaffolding and Equipment)
Figure 4-34 Note the horizontal braces on the frame section
to prevent racking. (Courtesy of Waco Scaffolding and Equipment)
70 Chapter 4
r
r
r
r
r
weather. The scaffolding components to which the ties are attached must also be checked for additional loads.
Free-standing scaffold towers must be restrained from tipping.
Use either guying or other means.
Equip all planked or staged areas with guide rails, mid-rails,
and toe boards along all open sides and ends of scaffold platforms.
Power lines near scaffolds are dangerous. Use caution and consult the power service company for advice.
Do not use ladders or makeshift devices on top of scaffolds to
increase height.
Do not overload scaffolds.
When using planking, keep the following in mind:
r Use only lumber that has been properly inspected and graded
for scaffold planks.
r Planking shall have at least 12 inches of overlap and extend
6 inches beyond center of support, or be cleated at both ends
to prevent sliding off supports.
r Fabricated scaffold planks and platforms (unless cleated or
restrained by hooks) shall extend over their end supports not
less than 6 inches or more than 12 inches.
r Secure plank to scaffold when necessary.
For rolling scaffold, the following additional rules apply:
r Do not ride rolling scaffolds.
r Secure or remove all material and equipment from platform
before moving scaffold.
r Caster brakes must be applied whenever scaffolds are not being
moved.
r Casters with plain stems shall be attached to the panel or adjustment screw by pins or other suitable means.
r Do not attempt to move a rolling scaffold without sufficient
help. Watch out for holes in the floor and overhead obstructions.
r Do not extend adjusting screws on rolling scaffolds more than
12 inches.
Site Equipment 71
r Use horizontal diagonal bracing near the bottom and at
20-foot intervals measured from the rolling surface.
r Do not use brackets on rolling scaffold without consideration
of overturning effect.
r The working platform height of a rolling scaffold must not
exceed four times the smallest base dimension unless guyed or
otherwise stabilized.
For putlogs and trusses, the following additional rules apply:
r Do not cantilever or extend putlogs or trusses as side brackets
without thorough consideration for loads to be applied.
r Putlogs and trusses should extend at least 6 inches beyond
point of support.
r Place proper bracing between putlogs or trusses when the span
of the putlog or truss is more than 12 feet.
r All brackets shall be seated correctly with side brackets parallel
to the frames and end brackets at 90◦ to the frames. Brackets
shall not be bent or twisted from normal position. Brackets
(except mobile brackets designed to carry materials) are to be
used as work platforms only and shall not be used for storage
of material or equipment.
r All scaffolding accessories shall be used and installed in accordance with the manufacturer’s recommended procedure.
Accessories shall not be altered in the field. Scaffolds, frames,
and their components manufactured by different companies
shall not be intermixed.
Summary
Ladders and scaffolding provide access for work high above the
ground. Step, single, and extension ladders are suitable for use by
single workers for tasks of short duration. Ladders are made of
wood, fiberglass, or metal. Ladders have a variety of attachments
that help stabilize the ladder at the top and bottom. Heavier ladders
should be raised by two workers.
Scaffolding provides a larger access area for longer jobs that require heavy materials at hand. Modular end frame, bracing units,
and planks can be built into a variety of temporary structures. Accessories for hoisting and extensions are part of the system. Be sure
to practice good safety when using ladders and scaffolding. Follow
standard rules and guidelines.
72 Chapter 4
Review Questions
1. What type of ladder should be used around electrical wires?
2. Why shouldn’t wooden ladders be painted?
3. When setting a ladder, how far above the roofline should it
extend?
4. How is a scaffold hoist installed and used?
5. Can ladders be used on top of scaffolding to increase the
height?
Push-up ladders are convenient, light and
.
What type of ladder is often used for interior painting?
What type of ladder is used frequently in outside siding work?
Explain how safety on ladders and scaffolds is important to a
carpenter.
10. Why would an electrician need a ladder on the job?
6.
7.
8.
9.
Chapter 5
Concrete-Block Construction
Concrete blocks (or cement blocks, as they are also known) provide
suitable building units. By the use of standard-size hollow blocks,
walls can be erected at a very reasonable cost and are durable, light
in weight, fire-resistant, and able to carry heavy loads.
The term concrete masonry is applied to building units molded
from concrete and laid by masons in a wall (see Figures 5-1 and
5-2). The units are made of Portland cement, water, and suitable aggregates (such as sand, gravel, crushed stone, cinders, burned shale,
or processed slag). The units are laid in a bed of cement mortar.
Figure 5-1 Two-core masonry block being installed. (Courtesy of Bilco
Company.)
73
74 Chapter 5
CAP BLOCK
8 IN. 8 IN. 16 IN.
CONCRETE BLOCK
TOP
4 FT 0 IN.
UNREINFORCED
1/2 IN. REINFORCING BARS
AT 4 FT. CENTERS IF WALL
IS MORE THAN 4 FT. HIGH.
6 FT 0 IN.
MAXIMUM WALL
HEIGHT
LOWER 2 FT 0 IN.
REINFORCED
FILL CORE SPACES
AROUND BAR WITH
CONCRETE
GROUND
LINE
18 IN. MINIMUM
DEPTH
8 IN.
1 FT 4 IN.
CROSS-SECTION OF GARDEN WALL
GRADE
SAME
AS WALL
THICKNESS
8 IN.
TWICE
THICKNESS
OF WALL
FOOTING BELOW
FROST LINE
1 FT 4 IN.
FOOTING FOR 8 IN. WALLS
Figure 5-2 Cross-section and view of a simple block wall. Vertical reinforcement rods are placed in the hollow cores at various
intervals.
Block Building Materials
The two key materials used in concrete block construction are the
standard blocks themselves (available in various sizes and shapes)
and the mortar used to bind the blocks together.
Standard Masonry Units
Concrete blocks are available in many sizes and shapes (see Figure 5-3). They are all sized based on multiples of 4 inches. The
fractional dimensions shown allow for the mortar (see Figure 5-4).
Some concrete blocks are poured concrete made of standard cement, sand, and aggregate. An 8-inch × 8-inch × 16-inch block
weighs about 40–50 pounds. Some use lighter natural aggregates
(such as volcanic cinders or pumice), while some are manufactured
aggregates (such as slag, clay, or shale). These blocks weigh 25–35
pounds.
In addition to the hollow-core types shown, concrete blocks are
available in solid forms. In some areas, they are available in sizes
other than those shown. Many of the same type have half the height,
normally 4 inches (actually 35/8 inches to allow for mortar). The
8 × 8 × 16 stretcher is most frequently used. It is the main block in
building a yard wall or a building wall. Corner or bull-nose blocks
with flat, finished ends are used at the corners of walls. Others have
special detents for windowsills, lintels, and doorjambs.
Concrete-Block Construction 75
STRETCHER (3 CORE)
8 IN. 8 IN. 16 IN.
4 IN. OR 6 IN. PARTITION
4 IN. OR 6 IN. 8 IN. 16 IN.
7 5/8 IN.
3 5/8 IN.
OR
5 5/8 IN.
STRETCHER (2 CORE)
8 IN. 8 IN. 16 IN.
7 5/8 IN.
15 5/8 IN.
7 5/8 IN.
15 5/8 IN.
15 5/8 IN.
7 5/8 IN.
10 IN. OR 12 IN. STRETCHER
10 IN. OR 12 IN. 8 IN. 16 IN.
7 5/8 IN.
STRETCHER
8 IN. 4 IN. 16 IN.
CORNER
8 IN. 8 IN. 16 IN.
7 5/8 IN.
7 5/8 IN.
3 5/8 IN.
15 5/8 IN.
9
5/8 IN.
7 5/8 IN.
15 5/8 IN.
15 5/8 IN.
7 5/8 IN.
OR
11 5/8 IN.
JAMB
8 IN. 8 IN. 16 IN.
BULLNOSE
8 IN. 8 IN. 16 IN.
SASH
8 IN. 8 IN. 16 IN.
15 5/8 IN.
7 5/8 IN.
7 5/8 IN.
7 5/8 IN.
3 5/8 IN.
7 5/8 IN.
15 5/8 IN.
4 IN. 2 IN.
FULL-CUT HEADER
8 IN. 8 IN. 16 IN.
3 5/8 IN.
2 3/4 IN.
7 5/8 IN.
15 5/8 IN.
BEAM OR LINTEL
8 IN. 8 IN. 16 IN.
SOLID
8 IN. 4 IN. 16 IN.
4 IN.
4 7/8 IN.
7 5/8 IN.
7 5/8 IN.
3 5/8 IN.
15 5/8 IN.
15 5/8 IN.
7 5/8 IN.
15 5/8 IN.
7 5/8 IN.
Figure 5-3 Standard sizes and shapes of concrete blocks.
Compressive strength is a function of the face thickness. Concrete
blocks vary in thickness of face, depending on whether they are to be
used for nonload-bearing walls (such as yard walls) or load-bearing
walls (such as for buildings).
76 Chapter 5
1 FT 4 IN. CC
7 5/8 IN.
8 IN. CC
15 5/8 IN.
Figure 5-4 Block size to allow for mortar joints.
Mortar
Mortar bonds the masonry units together to form a strong, durable
wall. The mortar must be chemically stable and resist rain penetration and damage by freezing and thawing. Mortar must have
sufficient strength to carry all loads applied to the wall for the life
of the building with a minimum of maintenance.
Mortar is widely used in home construction for all types of masonry walls. Masonry cement eliminates the need to stockpile and
handle extra material and reduces the chance of improper on-thejob proportioning. Consistent mortar color in successive batches is
easy to obtain when using masonry cement.
Water is added until the mortar is plastic and handles well under a trowel. Mortar should be machine-mixed whenever practical.
Masonry cement contains an air-entraining agent that causes the
formation of tiny air bubbles in the mortar. These bubbles make the
mortar more workable when plastic, slow the absorption of water
by the masonry unit, and reduce the possibility of weather damage.
Concrete masonry walls that are subject to average loading and
exposure should be laid up with mortar. The mortar is composed
of:
r One volume of masonry cement and 2–3 volumes of damp,
loose mortar sand
or,
r One volume of Portland cement, 1–11/4 volumes of hydrated
lime or lime putty, and 4–6 volumes of damp, loose mortar
sand
Concrete-Block Construction 77
Enough water is added to produce a workable mixture.
Concrete masonry walls and isolated piers are sometimes subject
to severe conditions. These conditions are extremely heavy loads,
violent winds, earthquakes, severe frost action, or other conditions
requiring extra strength. They should be laid up with mortar composed of:
r One volume of masonry cement, plus 1 volume of Portland
cement, and 4–6 volumes of damp, loose mortar sand
or,
r One volume of Portland cement, 2–3 volumes of damp, loose
mortar sand, and up to 1/4 volume of hydrated lime or lime
putty
Enough water is added to produce a workable mixture.
The type of mortar in bearing walls in heavily loaded buildings
is properly governed by the loading. Allowable working loads are
commonly 70 pounds per square inch (psi) of gross wall area when
laid in 1:1:6 (1 volume of Portland cement, 1 volume of lime putty
or hydrated lime, and 6 volumes of damp, loose mortar sand).
On small jobs, masonry cement can be purchased and the mortar
mixed with 1 part masonry cement to 3 parts sand (mix dry before adding water). A mortar mix can also be purchased to which
only water is added. When a mortar of maximum strength is desired for use in load-bearing walls, or walls subjected to heavy pressure, freezing, and thawing, a mortar made of 1 part Portland cement, 1 part masonry cement, and not more than 6 parts sand is
recommended.
Block Building Methods
There are some rather complicated problems for the first-time block
layer. Certain procedures must be followed, and the block-laying
done in sequence to allow for the addition of windows, doors and
floor joists. Basic block-laying practices are discussed in the following sections. Identification of the various blocks and their placement
and use is very important. The ratio of cement to sand is also important. Adding water to the mixture can be a matter of experience
with the mixer and demands of the mason.
Basic Block-Laying
The usual practice is to place the mortar in two separate strips, both
for the horizontal (or bed joints) and for the vertical (or end joints),
as shown in Figure 5-5. The mortar is applied only on the face shells
78 Chapter 5
MORTAR BOARD
POINTED TROWEL TO
HANDLE MORTAR
MORTAR
STAND BLOCK ON END
TO PLACE MORTAR FOR
VERTICAL JOINT
GUIDE
LINE
Figure 5-5 The usual practice in applying mortar to concrete
blocks.
of the block. This is known as face-shell bedding. The air spaces
thus formed between the inner and outer strips of mortar will help
produce a dry wall.
Applying Mortar to Blocks
Masons often stand the block on end and apply mortar for the end
joint. Sufficient mortar is put on to make sure that the joint will
be well filled (that is, will have no air spaces). Some masons apply
mortar on the end of the block previously laid, as well as on the end
of the block to be laid next to it, to make certain that the vertical
joint will be completely filled.
Placing and Setting Blocks
In placing (see Figure 5-6), the block that has mortar applied to
one end is picked up and shoved firmly against the block previously
placed. Note that the mortar is already in place in the bed or horizontal joints.
Mortar squeezed out of the joints is carefully cut off with the
trowel and either applied to the other end of the block or thrown
back onto the mortarboard for use later. The blocks are laid to touch
the guideline and are tapped with the trowel to get them straight and
Concrete-Block Construction 79
BLOCK IS PICKED UP AS
SHOWN AND SHOVED
AGAINST BLOCK
PREVIOUSLY LAID
MORTAR BED JOINT
GUIDE
LINE
Figure 5-6 The common method of picking up and setting
concrete block.
level (see Figure 5-7). In a well-constructed wall, mortar joints will
average 3/8 inch thick.
Tooling Mortar Joints
When the mortar has become firm, the joints are tooled, or finished.
Various tools are used for this purpose. A rounded or V-shaped
steel jointer is the tool most commonly used. Tooling compresses
the mortar in the joints, forcing it up tightly against the edges of
the block, and leaves the joints smooth and watertight. Some joints
may be cut off flush and struck with the trowel.
The concave and V joints are best for most work (see Figure 5-8).
While the raked and the extruded styles are recommended for interior walls only, they may be used outdoors in warm climates where
rain and freezing weather are at a minimum. In climates where freezing occurs, it is important that no joint permits water to collect.
Laying Blocks at Corners
In laying up corners (building the leads), place a taut line all the way
around the foundation, with the ends of the string tied together. It
80 Chapter 5
MASON'S LEVEL
BLOCK IS LEVELED
BY TAPPING
WITH TROWEL
EDGE OF BLOCK
PARALLEL TO LINE
GUIDE
LINE
EXCESS MORTAR
CUT OFF WITH TROWEL
Figure 5-7 A method of laying concrete blocks. Good workmanship requires straight courses with face of wall plumb.
is customary to lay up the corner blocks three or four courses high
and use them as guides in laying the rest of the walls.
A full width of mortar is placed on the footing (see Figure 5-9),
with the first course laid two or three blocks long each way from the
corner. The second course is a half-block shorter each way than the
first course; the third course is a half-block shorter than the second,
and so on. Thus, the corners are stepped back until only the corner
blocks are laid. Use a line and level frequently to see that the blocks
are laid straight and that the corners are plumb. It is customary that
such special units as corner blocks, door- and window-jamb blocks,
fillers, and veneer blocks be provided prior to starting the laying of
the blocks.
Building Walls Between Corners
In laying walls between corners, a line is stretched tightly from corner to corner to serve as a guide (see Figure 5-10). The line is fastened to nails or wedges driven into the mortar joints, so that when
stretched it just touches the upper outer edges of the block laid in
Concrete-Block Construction 81
(A) Concave joint: for exterior and interior walls.
(C) Raked joint: for interior walls.
(B) "V" joint: for exterior and interior walls.
(D) Extruded joint: for interior walls.
Figure 5-8 Four joint styles popular in block wall construction.
the corners. The blocks in the wall between corners are laid so that
they will just touch the cord in the same manner. In this way, straight
horizontal joints are secured. Prior to laying up the outside wall, the
door and window frames should be on hand to set in place as guides
for obtaining the correct opening.
LEVEL
FOR BUILDING UP CORNERS, USE MASON'S
LEVEL TO KEEP PLUMB AND STRAIGHT
FOOTING
Figure 5-9 Laying up corners when building with concrete
masonry-block units.
82 Chapter 5
1 IN. 2 IN. WITH SAW MARKS 8 IN. APART WILL
ASSIST TO SPACE COURSES AT CORNERS
STRETCH LINE BETWEEN CORNERS
TO SECURE STRAIGHT WALL
Figure 5-10 Procedure for laying concrete-block walls.
Building around Door and Window Frames
There are several acceptable methods of building door and window
frames in concrete masonry walls (see Figure 5-11). One method
used is to set the frames in the proper position in the wall. The
frames are then plumbed and carefully braced, after which the walls
are built up against them on both sides. Concrete sills may be poured
later.
The frames are often fastened to the walls by anchor bolts passed
through the frames and embedded in the mortar joints. Another
method of building frames in concrete masonry walls is to build
openings for them by using special jamb blocks (see Figure 5-12).
The frames are inserted after the wall is built. The only advantage to
this method is that the frames can be taken out without damaging
the wall, should it ever become necessary.
Placing Sills and Lintels
Building codes require that concrete-block walls above openings
be supported by arches or lintels of metal or masonry (plain or
reinforced). The arches or lintels must extend into the walls not less
than 4 inches on each side. Stone or other nonreinforced masonry
lintels should not be used unless supplemented on the inside of the
wall with iron or steel lintels (see Figure 5-13).
These are usually prefabricated, but may be made up on the job
if desired. Lintels are reinforced with steel bars placed 11/2 inch from
the lower side. The number and size of reinforcing rods depend upon
the width of the opening and the weight of the load to be carried.
Sills serve the purpose of providing watertight bases at the bottom
of wall openings. Since they are made in one piece, there are no joints
for possible leakage of water into the walls below. They are sloped
on the top face to drain water away quickly. They are usually made
to project 11/2 to 2 inches beyond the wall face, and are made with a
groove along the lower outer edge to provide a drain so that water
Concrete-Block Construction 83
2
2 FT
CROSSHATCHING INDICATES
BLOCK THAT MUST BE CUT BECAUSE
OF IMPROPER DIMENSIONS
3 FT
2 FT
8
.
2 IN
3 FT
2 FT
9 IN
IN.
.
IN.
.
9 IN
WRONG
N.
T6I
14 F
2 FT
.
0 IN
N.
T4I
3F
2F
N.
T8I
N.
T0I
4F
2 FT
8
IN.
RIGHT
14 F
N.
T8I
Figure 5-11 The right and wrong ways to plan door and window openings in block walls. (Courtesy Portland Cement Association)
dripping off the sill will fall free and not flow over the face of the
wall (possibly causing staining).
Slip sills are popular because they can be inserted after the wall
has been built. Therefore, they require no protection during construction. Since there is an exposed joint at each end of the sill,
special care should be taken to see that it is completely filled with
mortar and the joints packed tight.
Lug sills are projected into the concrete block wall (usually
4 inches at each end). The projecting parts are called lugs. There
JAMB BLOCK
(HALF LENGTH)
JAMB BLOCK
(FULL LENGTH)
JAMB BLOCKS
W
DO
IN ING
W EN
OP
OR
DO ING
EN
P
O
INSIDE FACE
OF WALL
Figure 5-12 A method of laying openings for doors and windows.
ONE- OR TWO-PIECE LINTELS
MAY BE USED AS REQUIRED
PRECAST
CONCRETE
SLIP SILL
INSIDE FACE OF WALL
PRECAST CONCRETE SILL
Figure 5-13 A method of inserting precast concrete lintels and
sills in concrete block walls.
Concrete-Block Construction 85
are no vertical mortar joints at the juncture of the sills and the
jambs. Like slip sills, lug sills are usually made to project from 11/2
to 2 inches over the face of the wall. The sill is provided with a
groove under the lower outer edge to form a drain. Frequently they
are made with washes at either end to divert water away from the
juncture of the sills and the jambs. This is in addition to the outward
slope on the sills.
At the time the lug sills are set, only the portion projecting into
the wall is bedded in mortar. The portion immediately below the
wall opening is left open and free of contact with the wall below.
This is done in case there is minor settlement or adjustments in the
masonry work during construction, thus avoiding possible damage
to the sill during the construction period.
Construction Methods
The steps in building concrete masonry walls are:
1.
2.
3.
4.
5.
6.
Mixing the mortar
Building the wall between corners
Building around door and window frames
Placing sills and lintels
Building interior walls
Attaching sills and plates
Walls
Thickness of concrete masonry walls is usually governed by building
codes, if any are in existence at the particular location. Eight inches
is generally specified as the minimum thickness for all exterior walls,
and for load-bearing interior walls. Partitions and curtain walls are
often made 3, 4, or 6 inches thick. The thickness of bearing walls in
heavily loaded buildings is properly governed by the loading.
Garden walls less than 4 feet high can be as thin as 4 inches, but
it is best to make them 8 inches thick. Walls over 4 feet high must
be at least 8 inches thick to provide sufficient strength.
A wall no more than 4 feet high needs no reinforcement. Merely
build up the fence from the foundation with block or brick and
mortar. Over 4 feet, however, reinforcement will be required, and
the fence should be of block, not brick. Set 1/2-inch-diameter steel
rods in the poured concrete foundation at 4-foot centers (see Figure
5-2). When you have laid the blocks (with mortar) up to the level
86 Chapter 5
of the top of the rods, pour concrete into the hollow cores around
the rods. Then continue on up with the rest of the layers of blocks.
In areas subject to possible earthquake shocks or extra-high
winds, horizontal reinforcement bars should also be used in high
walls. Use No. 2 (1/4-inch) bars or special straps made for the purpose. Figure 5-14 is a photograph of a block wall based on Figure
5-2. The foundation is concrete poured in a trench dug out of the
ground. Horizontal reinforcement is in the concrete, with vertical
members bent up at intervals. High column blocks (16 inches × 16
inches × 8 inches) are laid at the vertical rods. The columns are
evident in the finished wall shown in Figure 5-15.
Load-bearing walls are those used as exterior and interior walls in
residential and industrial buildings. Not only must the wall support
the roof structure, but also it must bear its own weight. The greater
the number of stories in the building, the greater the thickness the
Figure 5-14 Vertical reinforcement rods through double-thick
column blocks.
Concrete-Block Construction 87
Figure 5-15 A newly finished concrete-block wall. Note reinforcement columns at regular intervals.
lower stories must be to support the weight of the concrete blocks
above, as well as the roof structure.
Basement walls should not be narrower than the walls immediately above them, and not less than 12 inches for unit masonry
walls. Solid cast-in-place concrete walls are reinforced with at least
one 3/8-inch deformed bar (spaced every 2 feet) continuous from the
footing to the top of the foundation wall. Basement walls with 8inch hollow concrete blocks frequently prove very troublesome. All
hollow-block foundation walls should be capped with a 4-inch solid
concrete block, or the core should be filled with concrete.
Building Interior Walls
Interior walls are built in the same manner as exterior walls. Loadbearing interior walls are usually made 8 inches thick. Partitions that
are not load-bearing walls are usually 4 inches thick. Figure 5-16
shows a method of joining interior load-bearing walls to exterior
walls.
Sills and Plates
Sills and plates are usually attached to concrete block walls by means
of anchor bolts (see Figure 5-17). These bolts are placed in the cores
of the blocks, and the cores are filled with concrete. The bolts are
spaced about 4 feet apart under average conditions. Usually, 1/2-inch
bolts are used and should be long enough to go through two courses
of blocks and project through the plate about an inch to permit the
use of a large washer and the anchor-bolt nut.
88 Chapter 5
EXTERIOR WALL
PARTITION BLOCK
1/4 IN. 2 IN. METAL TIES
SPACED 4 FT 0 IN. MAXIMUM
INTERIOR
WALL
FOR EVERY SECOND COURSE
LAID INTO EXTERIOR WALL-USE
3/4 - LENGTH BLOCK
Figure 5-16 Showing detail of joining interior and exterior wall
in concrete block construction.
Installation of Heating and Ventilating Ducts
These ducts are provided for as shown on the architect’s plans.
The placement of the heating ducts depends upon the type of wall,
whether it is load-bearing or not. Figure 5-18 shows a typical example of placing the heating or ventilating ducts in an interior concrete
masonry wall.
Interior concrete-block walls that are not load-bearing, and that
are to be plastered on both sides, are frequently cut through to
provide for the heating duct, the wall being flush with the ducts on
either side. Metal lath is used over the ducts.
Electrical Outlets
These outlets are provided for by inserting outlet boxes in the walls
(see Figure 5-19). All wiring should be installed to conform to the
requirements of the National Electrical Code or local codes.
Concrete-Block Construction 89
2 IN. 6 IN. JOISTS
2 IN. 8 IN. PLATE
BOLTED
1 IN. 6 IN. ROOF
BOARDS
(A) Plate arrangement
at corners.
2 IN. 8 IN.
PLATE
.6
2 IN
ER
AFT
IN. R
2 IN. 6 IN. JOISTS
1 IN. 2 IN.
CAP
ANCHOR BOLT
1 IN. 6 IN. FACE
BOARDS
(B) Section
(through outside wall).
2-2 IN. 8 IN. PLATES
(WHERE REQUIRED)
FILL CORE IN
FIRST TWO COURSES
WITH MORTAR
ALL CORES SHOULD
BE FILLED WITH
CONCRETE OR A 4INCH SOLID BLOCK
LAYED AS TOP ROW.
ANCHOR
BOLT
PIECE OF METAL LATH
IN SECOND MORTAR
JOINT UNDER CORE
(C) Detail of anchor
bolt fastening.
Figure 5-17 Showing details of methods used to anchor sills
and plates to concrete block walls.
90 Chapter 5
PARTITION BLOCKS
VENTILATOR OR
HEATING DUCTS
Figure 5-18 Method of installing ventilating and heating duct
in concrete block walls.
Insulation
Block walls can (and should) be insulated in a number of ways. One
way is to secure studs to the walls with cut nails or other fasteners,
then staple batt insulation to the studs. However, a simpler way
is with Styrofoam insulation. This comes in easy-to-cut sheets. It
is applied to the interior walls with mastic and then, because it is
TYPE OF WIRING
AS PER CODE
REQUIREMENTS
CUT HOLE IN
BLOCK WITH
CHISEL TO
ACCOMMODATE
SWITCH OR BOX
SET BOX IN
Figure 5-19 Method showing installation of electrical switches
and outlet boxes in concrete-block walls.
Concrete-Block Construction 91
Figure 5-20 Styrofoam rigid insulation board can be glued to
masonry.
flammable, covered with gypsum drywall or other noncombustible
material (see Figure 5-20).
The Styrofoam may also be used on the exterior of the wall. In
this case, it is secured only to that part of the foundation above the
earth and one foot below. The Styrofoam, in turn, is covered with
cement, or other mixture as specified by the manufacturer.
Another way is by filling the cores of concrete block units in all
outside walls with granulated insulation or, the preferred way, by
inserting rigid foam insulation.
Flashing
Adequate flashing with rust- and corrosion-resisting material is of
the utmost importance in masonry construction, since it prevents
water from getting through the walls at vulnerable points. Points
requiring protection by flashing are:
r Tops and sides of projecting trim
r Under coping and sills
r At intersection of wall and roof
r Under built-in gutters
r At intersection of chimney and roof
r At all other points where moisture is likely to gain entrance
92 Chapter 5
Flashing material usually consists of No. 26-gage (14-ounce) copper
sheet or other approved noncorrodible material.
Floors
In concrete masonry construction, floors may be made entirely of
wood or concrete, although a combination of concrete and wood
is sometimes used. Wooden floors (see Figure 5-21) must be framed
with one governing consideration: they must be made strong enough
to carry the load. The type of building and its use will determine
the type of floor used, the thickness of the sheathing, and approximate spacing of the joists. The girder is usually made of heavy
WOOD JOIST
JAMB BLOCK
WOOD
SUBFLOORING
Figure 5-21 Method of installing wooden floor joists in concrete blocks.
Concrete-Block Construction 93
timber and is used to support the lighter joists between the outside
walls.
Concrete Floors
There are usually two types of concrete floors:
r Cast-in-place concrete
r Precast joists used with cast-in-place or precast concrete units
Cast-in-Place
Cast-in-place concrete floors (Figure 5-22), are used in basements
(and in residences without basements) and are usually reinforced by
means of wire mesh to provide additional strength and to prevent
cracks in the floor. This type of floor is used for small areas. It used
to be popular for porch floors.
Figure 5-23 shows another type of cast-in-place concrete floor.
This floor has more strength because of the built-in joist. It can be
used for larger areas.
Precast Joists
Figure 5-24 shows the precast-joist type. The joists are set in place,
the wooden forms inserted, the concrete floor poured, and the forms
3 5/8 IN. 7 5/8 IN. 15 5/8 IN.
SOLID BLOCK
CONCRETE
BATTS
1 IN. INSULATION
REINFORCED
CONCRETE
SLAB FLOOR
Figure 5-22 Cast-in-place concrete floor supported by the
concrete block wall.
REINFORCING BARS
WOODEN FORM
CONCRETE SLAB
1 IN. INSULATION
JOISTS
3 5/8 IN. 7 5/8 IN. 15 5/8 IN.
SOLID BLOCK
SOLID BLOCK OR CORES FILLED WITH
CONCRETE IN COURSE UNDER JOISTS
IN ACCORDANCE WITH LOCAL
REQUIREMENTS
2 IN. 8 IN. BOARDS
2-2 IN. 4 IN. POSTS
2 IN. 6 IN. 30 IN. O.C.
2-2 IN. 6 IN. LEDGERS
4 FT 0 IN. O.C.
Figure 5-23 Framing construction for cast-in-place concrete
floor.
SPECIAL FILLER UNIT
USED BETWEEN JOISTS
HEADER BLOCK
1 IN. INSULATION
3 5/8 IN. 7 5/8 IN. 15 5/8 IN. SOLID BLOCK
REINFORCING
BARS
CONCRETE
SLAB
FORM
BOARDS
WIRE
HANGERS
2 IN. 4 IN.
SPREADERS
30 IN. O.C.
SOLID BLOCK OR CORES FILLED WITH
CONCRETE IN COURSE UNDER FLOOR UNITS IN
ACCORDANCE WITH LOCAL REQUIREMENTS
Figure 5-24 Illustrating framing of precast concrete-floor
joists.
Concrete-Block Construction 95
3 5/8 IN. 7 5/8 IN. 15 5/8 IN. SOLID BLOCK
1 IN. INSULATION
CONCRETE BATTS
PRECAST CONCRETE FLOOR
UNITS MADE IN PLANT
SOLID BLOCK OR CORES FILLED WITH
CONCRETE IN COURSE UNDER FLOOR
UNITS IN ACCORDANCE WITH LOCAL
REQUIREMENTS.
STANDARD
BLOCK UNITS
Figure 5-25 Method of framing cored concrete-floor units into
concrete walls.
removed. Another type of precast-joist concrete floor (see Figure
5-25) consists of precast concrete joists covered with cast-in-place
concrete slabs. The joists are usually made in a concrete-products
plant.
Usual spacing of the joists is from 27 to 33 inches, depending
upon the span and the load. The cast-in-place concrete slab is usually
2 or 21/2 inches thick, and extends down over the heads of the joists
about 1/2 inch. Precast concrete joists are usually made in 8-, 10-, and
12-inch depths. The 8-inch joists are used for spans up to 16 feet;
the 10-inch joists are for spans between 16 and 20 feet; and the
12-inch joists are for spans from 20 to 24 feet.
It is customary to double the joists under the partition where
masonry partitions do not support a load. Moreover, they are placed
parallel to the joists. If the partition runs at right angles to the joists,
the usual practice is to design the floor to carry an additional load
of 20 pounds per square foot. Precast concrete joists may be left
exposed on the underside and painted, or a suspended ceiling may be
used. An attractive variation in exposed joist treatment is to double
the joists and increase the spacing. Where this is done, the concrete
slab is made 21/2 inches thick for spacings up to 48 inches, and 3
96 Chapter 5
inches thick for spacings from 48 to 60 inches. Joists may be doubled
by setting them close together, or by leaving a space between them
and filling the space with concrete.
Wood Floors
Where wood-surfaced floors are used in homes, any type of hardwood (such as maple, birch, beech, or oak) may be laid over the
structural concrete floor. The standard method of laying hardwood
flooring over a structural-concrete floor slab is to nail the boards to
2-inch × 2-inch or 2-inch × 3-inch sleepers. These sleepers may be
tied to the tops of the stirrups protruding from the precast concrete
joists. They should be placed not more than 16 inches on center,
preferably 12 inches in residential construction. Before the hardwood flooring is nailed to the sleepers, the concrete floor must be
thoroughly hardened and free from moisture. It is also best to delay
laying the hardwood floors until after drywall installers or plasterers
have finished work.
Certain types of parquet and design wood floorings are laid
directly on the concrete, being bonded to the surface with adhesive. The concrete surface should be troweled smooth and be
free from moisture. No special topping is required. The ordinary
level-sidewalk finish provides a satisfactory base. Manufacturer’s
directions for laying this type of wood flooring should be followed
carefully to ensure satisfactory results in the finished floor.
Summary
Concrete blocks provide a very good building material. Blocks are
very reasonable in cost, durable, fire-resistant, and can carry heavy
loads. The thickness of concrete blocks is generally 8 inches (except
for partition blocks), which is generally specified as the minimum
thickness for all exterior walls and for load-bearing interior walls.
Partitions and curtain walls are often made 3, 4, or 6 inches thick.
Concrete blocks are made in several sizes and shapes. For various
openings (such as windows or doors), a jamb block is generally
used to adapt to various frame designs. Building codes require that
concrete block walls above openings shall be supported by arches
of steel or precast masonry lintels. Lintels are usually prefabricated,
but may be made on the job if desired. They are reinforced with
steel bars placed approximately 11/2 inches from the lower side.
In concrete-block construction, floors may be entirely of wood
or concrete, although a combination of the two materials is sometimes used. Joists may be installed in the block wall by using jamb
Concrete-Block Construction 97
blocks, or by installing a sill plate at the top of the wall. Concrete
floors are generally of the cast-in-place, precast unit, or precast-joist
types.
Review Questions
1. What is the general thickness of concrete blocks?
2. What are the standard measurements of a full-size concrete
block?
What are lintels? Why are they used?
What are precast joists?
What are concrete bats?
How is a jamb block different from a regular block?
What are the two types of concrete floors?
How is a partition block different from regular building
blocks?
9. How far do lug sills project into the concrete block?
10. Why are slip sills popular?
3.
4.
5.
6.
7.
8.
Chapter 6
Frames and Framing
Good material and workmanship will be of very little value unless
the underlying framework of a building is strong and rigid. The
resistance of a house to such forces as tornadoes and earthquakes,
and control of cracks caused by settlement, all depends on a good
framework.
Methods of Framing
Although it is true that no two buildings are put together in exactly
the same manner, disagreement exists among architects and carpenters as to which method of framing will prove most satisfactory for
a given condition. Light-framed construction may be classified into
the following three distinct types:
r Balloon frame
r Post-and-beam
r Platform frame
Balloon-Frame Construction
The principal characteristic of balloon framing is the use of studs
extending in one piece from the foundation to the roof (see Figure
6-1). The joists are nailed to the studs and supported by a ledger
board set into the studs. Diagonal sheathing may be used instead of
wallboard to eliminate corner bracing.
Post-and-Beam Construction
The post-and-beam construction is the oldest method of framing
used in the United States. It is still used, particularly where the
builder wants large open areas in a house. This type of framing
is characterized by heavy timber posts (see Figure 6-2), often with
intermediate posts between.
Platform Frame Construction
Platform (or western) framing is characterized by platforms independently framed, the second or third floor being supported by the
studs from the first floor (see Figure 6-3). The chief advantage in
this type of framing (in all-lumber construction) lies in the fact that
if there is any settlement caused by shrinkage, it will be uniform
throughout and will not be noticeable.
99
100 Chapter 6
HIP
TIE TO BE USED ONLY
WHERE ROUGH FLOORING
IS OMITTED
JOIST
RAFTER
PARTITION
CAP
PLATE
BRIDGING
STUD
JOIST
STUD
PARTITION
CAP
ROUGH
FLOORING
DRAFT
STOPPING
BRIDGING
LEDGER
BOARD
OR RIBBON
JOIST
DIAGONAL
BRACING SET
INTO FACES OF
STUDDING
BUILT UP
GIRDER
LEDGER OR
SPIKING
STRIP
SILL
CROSS BRIDGING
CORNER POST
ROUGH FLOORING
MASONRY WALL
WALL BOARD
Figure 6-1 Details of balloon-frame construction.
Framing Terms
The following sections describe terms and concepts commonly used
in reference to framing.
Sills
The sills are the first part of the framing to be set in place. Sills may
rest directly on foundation piers or other type of foundation, and
Frames and Framing 101
RAFTER
SOLID
PLATE
BRACE
JOINT
PIN
FLOOR
BEAM OR
JOIST
SUNK
OR
DROPPED
GIRT
SOLID
CORNER
POST
GIRTH
POST
PIN
GIRTH
JOINT
RAISED
OR FLUSH
GIRT
SILL
JOINT
SOLID
SILL
Figure 6-2 Post-and-beam frame construction. Heavy solid
timbers are fastened together with pegged mortise-and-tenon
joints.
102 Chapter 6
HIP
RAFTER
CROSS
BRIDGING
PARTITION
CAP
ROUGH FLOOR
STUD
BRIDGING
PLATE
JOIST
SOLE
STUD
SOLID
BRIDGING
SOLE
HEADER
PARTITION
CAP
GIRT
BRIDGING
ROUGH FLOOR
JOIST
STUD
SOLE
SOLE
GIRDER
HEADER
LEDGER OR
SPIKING STRIP
CROSS BRIDGING
ROUGH FLOOR
SILL
DIAGONAL BRACING
SET INTO FACE OF STUD
CORNER POST
SHEATHING
MASONRY WALL
Figure 6-3 Details of platform, or western, construction.
usually extend all around the building. When box sills are used, the
part of the sill that rests on the foundation wall is called the sill
plate.
Girders
A girder may be a single beam or built-up thinner lumber (see Figure
6-4). Girders usually support joists, whereas the girders themselves
Frames and Framing 103
are supported by bearing walls or columns. When a girder is supported by a wall or column, it must be remembered that such a
member delivers a large concentrated load to a small section of the
wall or column. Therefore, care must be taken to see that the wall
or column is strong enough to carry the load imposed upon it by
the girder. Girders are generally used only where the joist will not
safely span the distance. The size of a girder is determined by the
span length and the load to be carried.
JOISTS
4 IN. MINIMUM
BEARING
GIRDER
POST
Figure 6-4 Built-up wooden girders.
Joists
Joists are the pieces that make up the body of the floor frame, and
to which the flooring and subflooring are nailed (see Figure 6-5).
They are usually 2 or 3 inches thick, with depth varying to suit
conditions. Joists carry a dead load (composed of the weight of
the joists themselves, in addition to the flooring) and a live load
(composed of the weight of furniture and persons).
Subflooring
A subfloor is laid on the joists and nailed to them (see Figure 6-5).
By the use of subflooring, floors are made much stronger, since the
104 Chapter 6
CORNER POST
STUDS
BUILT
UP
SILL
SOLE
PLYWOOD
SUBFLOOR
SILL
PLATE
JOISTS
ANCHOR
BOLT
Figure 6-5 Detail views of floor joists and subfloor.
floor weight is distributed over a larger area. It may be laid before
or after the walls are framed, but preferably before. The subfloor
can then be used as a floor to work on while framing the walls. The
material for subflooring can be sheathing boards (see Figure 6-6) or
plywood (see Figure 6-5).
Headers and Trimmers
When an opening is to be made in a floor, a header or trimmer holds
the ends of the joists. The header or trimmer should be made heavier
than the joists to carry the extra load. The header must be framed
in between the trimmers to receive the ends of the short joists.
Walls and Partitions
All walls and partitions in which the structural elements are wood
are classed as frame construction. Their structural elements are
closely spaced. They contain a number of vertical members called
studs (see Figure 6-5). These are arranged in a row with their ends
bearing on a long longitudinal member called the bottom plate or
sole plate, and their tops are capped with another plate called the
top plate. The bearing strength of the stud walls is governed by the
length of the studs.
The top plate serves two purposes: to tie the studding together
at the top and form a finish for the walls, and to furnish a support
Frames and Framing 105
SUBFLOOR
HEADER
JOIST
Figure 6-6 Method of laying lumber subflooring.
for the lower end of the rafters. The top plate further serves as a
connecting link between the ceiling and the walls.
The plate is made up of one or two pieces of timber of the same
size as the studs. In cases where studs at the end of the building
extend to the rafters, no plate is used. When it is used on top of
partition walls, it is sometimes called a cap. The sole plate is the
bottom horizontal member on which the studs rest.
Partition walls are any walls that divide the inside space of a
building. In most cases, these walls are framed as a part of the building. In cases where floors are to be installed after the outside of the
building is completed, the partition walls are left unframed. There
are two types of partition walls, bearing and non-bearing. The bearing type (also called load-bearing) supports the structure above. The
nonbearing type supports only itself. It may be put in at any time
after the framework is installed. Only one cap or plate is used.
A sole plate should be used in every case, as it helps to distribute
the load over a large area. Partition walls are framed in the same
manner as outside walls, and inside door openings are framed the
same as outside openings. Where there are corners (or where one
partition wall joins another), corner posts or T-posts are used in
the outside walls. These posts provide nailing surfaces for the inside
wall finish.
106 Chapter 6
GIRDER
LEDGER STRIP
JOIST
LEDGER STRIP
Figure 6-7 Detail of girder and method of supporting joists by
using a ledger strip.
Ledger Plates
In connecting joists to girders and sills where piers are used, a 2-inch
× 4-inch piece is nailed to the face of the sill or girder and flush with
the bottom edge, as shown in Figure 6-7. This is called a ledger.
Braces
Braces are used as a permanent part of the structure. They stiffen
the walls and keep corners square and plumb. Braces also prevent
the frame from being distorted by lateral forces (such as by wind or
by settlement). These braces are placed wherever the sills or plates
make an angle with the corner post or with a T-post in the outside
wall. The brace extends from the sill or sole plate to the top of the
post, forming an angle of approximately 60˚ with the sole plate and
an angle of 30˚ with the post.
Studs
Studs are the main vertical framing members. They are installed between the top and sole plates. Before studs are laid out, the windows
and door openings are laid out. The studs are normally set 16 inches
apart (on centers), but there is a trend today toward 24-inch centers.
In most instances, the studs are nailed to the top and sill plates while
the entire assembly is resting flat on the deck. The wall is then raised
into position.
Frames and Framing 107
Bridging
Walls of frame buildings are bridged in most cases in order to increase their strength. There are two methods of bridging: the diagonal and the horizontal. Diagonal bridging is nailed between the
studs at an angle. It is more effective than horizontal bridging, because it forms a continuous truss and tends to keep the walls from
sagging. Whenever possible, both outside and inside walls should
be bridged alike.
Horizontal bridging is nailed between the studs, halfway between
the sole and top plate. This bridging is cut to lengths that correspond
to the distance between the studs at the bottom. Such bridging not
only stiffens the wall, but also helps straighten the studs.
Metal bridging is made of forged thin strips of metal secured to
tops of joists.
Rafters
In all roofs, the pieces that make up the main body of the framework
are called the rafters. They do for the roof what the joists do for the
floor or the studs do for the wall. The rafters are inclined members,
usually spaced from 16 to 24 inches on center, that rest at the bottom
on the plate and are fastened on center at the top in various ways
according to the form of the roof. The plate forms the connecting
link between the wall and the roof and is really a part of both.
The size of the rafters varies, depending upon the length and the
distance at which they are spaced. The connection between the rafter
and the wall is the same in all types of roofs. They may or may not
extend out a short distance from the wall to form the eaves and to
protect the sides of the building.
Lumber Terms
The basic construction material in carpentry is lumber. There are
many kinds of lumber, and they vary greatly in structural characteristics. Here, we deal with lumber common to construction carpentry,
its application, the standard sizes in which it is available, and the
methods of computing lumber quantities in terms of board feet.
Standard Sizes of Lumber
Lumber is usually sawed into standard lengths, widths, and thicknesses. This permits uniformity in planning structures and in ordering material. Table 6-1 lists the common widths and thicknesses
of wood in rough and in dressed dimensions in the United States.
Standards have been established for dimension differences between
nominal size and the standard size (which is actually the reduced size
108 Chapter 6
Table 6-1 Guide to Size of Lumber
What You Get
What You Order
Dry or Seasoned*
Green or Unseasoned**
1×4
1×6
1×8
1 × 10
1 × 12
2×4
2×6
2×8
2 × 10
2 × 12
4×4
4×6
4×8
4 × 10
4 × 12
3/ × 31/
4
2
3/ × 51/
4
2
3/
1
4 × 7 /4
3/
1
4 × 9 /4
3/ × 111/
4
4
11/2 × 31/2
11/2 × 51/2
11/2 × 71/4
11/2 × 91/4
11/2 × 111/4
31/2 × 31/2
31/2 × 51/2
31/2 × 71/4
31/2 × 91/4
31/2 × 111/4
25/
9
32 × 3 /16
25/
5
32 × 5 /8
25/
1
32 × 7 /2
25/
1/
×
9
32
2
25/
1
32 × 11 /2
19/16 × 39/16
19/16 × 55/8
19/16 × 71/2
19/16 × 91/2
19/16 × 111/2
39/16 × 39/16
39/16 × 55/8
39/16 × 71/2
39/16 × 91/2
39/16 × 111/2
∗ 19 percent moisture content or less.
∗∗ More than 19 percent moisture content.
when dressed). It is important that these dimension differences be
taken into consideration when planning a structure. A good example of the dimension differences may be illustrated by the common
2 × 4. As may be seen in the table, the familiar quoted size (2 × 4)
refers to a rough or nominal dimension, but the actual standard size
to which the lumber is dressed is 11/2 × 31/2.
Framing Lumber
The frame of a building consists of the wooden form constructed
to support the finished members of the structure. It includes such
items as posts, girders (beams), joists, subfloor, sole plate, studs,
and rafters. Softwoods are usually used for lightwood framing and
all other aspects of construction carpentry considered in this book.
They are cut into the standard sizes required for light framing (including 2 × 4, 2 × 6, 2 × 8, 2 × 10, 2 × 12, and all other sizes
required for framework), with the exception of those sizes classed
as structural lumber.
Although No. 1 and No. 3 common are sometimes used for framing, No. 2 common is most often used, and is, therefore, most often
stocked and available in retail lumberyards in the common sizes
for various framing members. However, the size of lumber required
Frames and Framing 109
for any specific structure will vary with the design of the building
(such as light-frame or heavy-frame,) and the design of the particular
members (such as beams or girders).
The exterior walls of a frame building usually consist of three
layers: sheathing, building paper, and siding. Sheathing lumber is
usually 1 × 6 boards or 1 × 8 boards, No. 2 or No. 3 common
softwood. It may be plain, tongue-and-groove, or ship lapped. The
siding lumber may be grade C, which it most often used. Siding is
usually procured in bundles consisting of a given number of square
feet per bundle, and comes in various lengths up to a maximum of
20 feet. Sheathing grade (CDX) plywood is used more often than
lumber for sheathing.
Summary
After the foundation walls have been completed, the first part of
framing is to set the sills in place. The sills usually extend all around
the building. Where double or built-up sills are used, the joints are
staggered and the corner joints are lapped.
Where floor joists span a large distance, girders are used to help
support the load. The size of a girder depends on the span length of
the joists. Girders may be either a steel I-beam, or can be built on
the job from 2 × 8 or 2 × 10 lumber placed side-by-side.
Joists are the pieces that make up the body of the floor frame, and
to which the subflooring is nailed. The joists are usually 2 × 6 or 2 ×
8 lumber commonly spaced 16 or 24 inches apart. The subflooring
is generally installed before the wall construction is started, and in
this manner, the subfloor can serve as a work floor.
Review Questions
Explain the purpose of the sill plate, floor joists, and girder.
What is the purpose of the subflooring?
What is a ledger strip?
What is a sole plate?
Where are headers and trimmers used?
How can light-framed construction be classified?
What is meant by balloon framing?
How is post-and-beam type construction anchored to the foundation?
9. What is a joist?
10. What is a cap?
1.
2.
3.
4.
5.
6.
7.
8.
Chapter 7
Floors, Girders, and Sills
By definition, a girder is a principal beam extending from wall-towall of a building, affording support for the joists or floor beams
where the distance is too great for a single span. Girders may be
either built-up wood (see Figure 7-1) or steel (see Figure 7-2).
Girders
There are girders that have been engineered to fit a particular job.
Shopping malls, churches, and schools all require long girders to
support an open space for a variety of reasons. The construction of
girders and the placement of them are important to carpenters and
designers as well as builders.
Construction of Girders
Girders can be built up of wood if select stock is used. Be sure it
is straight and sound (see Figure 7-1). If the girders are to be built
up of 2 × 8 or 2 × 10 stock, place the pieces on the sawhorses and
nail them together. Use the piece of stock that has the least amount
of warp for the centerpiece and nail other pieces on the sides of the
center stock. Use a common nail that will go through the first piece
and nearly through the centerpiece. Square off the ends of the girder
after the pieces have been nailed together. If the stock is not long
enough to build up the girder the entire length, the pieces must be
built up by staggering the joints. If the girder supporting post is to
be built up, it is to be done in the same manner as described for the
girder.
Table 7-1 is an example of sizes of built-up wood girders for
various loads and spans, based on Douglas fir 4-square framing
lumber. All girders are figured as being made with 2-inch dressed
stock. The 6-inch girder is figured three pieces thick; the 8-inch
girder four pieces thick; the 10-inch girder five pieces thick, and the
12-inch girder six pieces thick. For solid girders, multiply the load in
Table 7-1 by 1.130 when 6-inch girders are used; 1.150 when 8-inch
girders are used; 1.170 when 10-inch girders are used, and 1.180
when 12-inch girders are used. Other woods will require figures
based on the specific wood and grade.
Placing Basement Girders
Basement girders must be lifted into place on top of the piers, and
walls built for them, and set perfectly level and straight from end
111
112 Chapter 7
NOTCH
JOIST
WOOD GIRDER
JOIST
ALLOW SPACE
UNDER JOIST
LEDGER
STAGGERED JOINTS
(A)
SCAB
SPACE
JOIST
LEDGER
WOOD GIRDER
(B)
Figure 7-1 Built-up wood girder: (A) the floor joists are
notched to fit over the girder; (B) a connecting scab is used
to tie joists together.
to end. Some carpenters prefer to give the girders a slight crown
of approximately 1 inch in the entire length, which is a wise plan
because the piers will generally settle. They settle a little more than
the outside walls.
When there are posts instead of brick piers used to support the
girder, the best method is to temporarily support the girder by uprights made of 2 × 4 joists resting on blocks on the ground below.
Floors, Girders, and Sills 113
SCAB (NAIL TO EACH JOIST)
LEDGER
ALLOW
SPACE
BEAM
JOIST
BOLT
(A)
ALLOW SPACE
SCAB
JOIST
STRAP TIES
BLOCKING
(B)
Figure 7-2 Steel beam used as girder: (A) floor joists rest on
wooden ledger bolted to steel I-beam girder; (B) floor joists
rest directly on bottom flange of I-beam. The joists are connected above with a scab board.
When the superstructure is raised, these can be knocked out after
the permanent posts are placed. The practice of temporarily shoring
the girders, and not placing the permanent supports until after the
superstructure is finished, is favored by many builders, and it is a
good idea for carpenters to know just how it should be done. Permanent supports are usually made by using 3- or 4-inch steel pipe
set in a concrete foundation, or footing that is at least 12 inches
deep. They are called Lally columns and are filled with concrete for
greater strength.
114 Chapter 7
Table 7-1 Examples of Girder Sizes
Load per
Linear Foot
of Girder
750
900
1050
1200
1350
1500
1650
1800
1950
2100
2250
2400
2550
2700
2850
3000
3150
3300
Length of Span
6-foot
6 × 8 in.
6×8
6×8
6 × 10
6 × 10
8 × 10
8 × 10
8 × 10
8 × 12
8 × 12
10 × 12
10 × 12
10 × 12
10 × 12
10 × 14
10 × 14
10 × 14
12 × 14
7-foot
6 × 8 in.
6×8
6 × 10
8 × 10
8 × 10
8 × 10
8 × 12
8 × 12
10 × 12
10 × 12
10 × 12
10 × 14
10 × 14
10 × 14
12 × 14
12 × 14
12 × 14
12 × 14
8-foot
6 × 8 in.
6 × 10
8 × 10
8 × 10
8 × 10
8 × 12
10 × 12
10 × 12
10 × 12
10 × 14
10 × 14
10 × 14
12 × 14
12 × 14
12 × 14
9-foot
6 × 10 in.
6 × 10
8 × 10
8 × 10
8 × 12
10 × 12
10 × 12
10 × 12
10 × 14
12 × 14
12 × 14
12 × 14
12 × 14
10-foot
6 × 10 in.
8 × 10
8 × 12
8 × 12
10 × 12
10 × 12
10 × 14
10 × 14
12 × 14
12 × 14
12 × 14
Sills
A sill is that part of the sidewalls of a house that rests horizontally
upon, and is securely fastened to, the foundation. There are various
types of sills and they may be divided into two general classes:
r Solid
r Built-up
The built-up sill has become more or less a necessity because of the
high cost and scarcity of larger-sized timber. The work involved in
sill construction is very important for the carpenter. The foundation
wall is the support upon which the entire structure rests. The sill is
the foundation on which all the framing structure rests, and is the
real point of departure for actual carpentry and joinery activities.
The sills are the first part of the frame to be set in place. They rest
directly on the foundation piers or on the ground, and may extend
all around the building.
Floors, Girders, and Sills 115
Types of Sills
The type of sill used depends upon the general type of construction.
Types of sills include the following:
r Box sills
r T-sills
r Braced-framing sills
r Built-up sills
Box Sills
Box sills are often used with the very common style of platform
framing, either with or without the sill plate (see Figure 7-3). In this
type of sill, the part that lies on the foundation wall or ground is
called the sill plate. The sill is laid edgewise on the outside edge of
the sill plate. It is doubled and bolted to the foundation. Aluminum
is set in asphaltum beneath it as a termite barrier.
STUD
STUD
ROUGH
FLOOR
ROUGH
FLOOR
SOLE
SOLE
HEADER
HEADER
SILL
JOIST
JOIST
MASONRY
WALL
DOUBLE
SILL
STUDS
(A) First floor.
(B) Second floor.
Figure 7-3 Details of platform framing of sill plates and joists
for western frame box-sill construction.
T-Sills
There are two types of T-sill construction, one commonly used in
the South (or in a dry, warm climate), and one used in the North
and East (where it is colder). Their construction is similar, except in
the East, where the T-sills and joists are nailed directly to the studs,
as well as to the sills. The headers are nailed in between the floor
joists.
116 Chapter 7
Braced Framing Sills
With braced framing sills, the floor joists are notched out and nailed
directly to the sills and studs.
Built-Up Sills
Where built-up sills are used, the joints are staggered. If piers are
used in the foundation, heavier sills are used. These sills are of single
heavy timber or are built up of two or more pieces of timber. Where
heavy timber or built-up sills are used, the joints should occur over
the piers. The size of the sill depends on the load to be carried and
on the spacing of the piers. Where earth floors are used, the studs
are nailed directly to the sill plates.
For two-story buildings (and especially in locations subject to
earthquakes or tornadoes), a double sill is desirable, because it affords a larger nailing surface for sheathing brought down over the
sill, and ties the wall framing more firmly to its sills. In cases where
the building is supported by posts or piers, it is necessary to increase
the sill size, since the sill supported by posts acts as a girder.
Since it is not necessary that the sill be of great strength in most
types of construction, the foundation will provide uniformly solid
bearing throughout its entire length. The main requirements are:
r Resistance to crushing across the grain
r Ability to withstand decay and attacks of insects
r Availability of adequate nailing area for studs, joists, and
sheathing
Anchorage of Sill
It is important (especially in locations with strong winds) that buildings be thoroughly anchored to the foundation (see Figure 7-4). Anchoring is accomplished by setting at suitable intervals (6 to 8 feet)
1/ -inch bolts that extend at least 18 inches into the foundation.
2
They should project above the sill to receive a good-sized washer
and nut. With hollow tile, concrete blocks, and material of cellular
structure, particular care should be taken in filling the cells in which
the bolts are placed solidly with concrete.
Setting the Sills
After the girder is in position, the sills are placed on top of the foundation walls, are fitted together at the joints, and leveled throughout.
The last operation can be done either by a sight level or by laying
them in a full bed of mortar and leveling them with the anchor bolts
(see Figure 7-4). On the other hand, it can be left loose and then all
the bolts can be tightened as needed to bring the sill level.
Floors, Girders, and Sills 117
L
SIL
PL
E
AT
ANCHOR BOLT
Figure 7-4 One way to anchor sill to foundation. (Courtesy of the National
Forest Products Assn.)
Sills that are to rest on a wall of masonry should be pressure
treated, or kept up at least 18 inches above the ground, as decaying sills are a frightful source of trouble and expense in wooden
buildings. Sheathing, paper, and siding should, therefore, be very
carefully installed to exclude all wind and wet weather.
Floor Framing
After the girders and sills have been placed, the next operation consists in sawing to size the floor beams or joists of the first floor, and
placing them in position on the sills and girders. If there is a great
variation in the size of timbers, it is necessary to cut the joists 1/2
inch narrower than the timber so that their upper edges will be in
alignment. This sizing should be made from the top edge of the joist
(see Figure 7-5). When the joists have been cut to the correct dimension, they should be placed upon the sill and girders, and spaced 16
inches between centers, beginning at one side or end of a room. This
is done to avoid wasting material.
Connecting Joist to Sills and Girders
Joists can be connected to sills and girders by several methods, but
the prime consideration, of course, is to be sure that the connection
is able to hold the load that the joists will carry.
The placing of the girders is an important factor in making the
connection. The joists must be level. Therefore, if the girder is not
the same height as the sill, the joists must be notched. In placing
joists, always have the crown up, since this counteracts the weight
118 Chapter 7
VERTICAL MEASUREMENT
MEASURE FROM TOP EDGE
TOP
TOP
VARIATION
Figure 7-5 Showing the variation of joist width.
on them. In most cases, there will be no sag below a straight line.
When a joist is to rest on plates or girders, the joist is cut long enough
to extend the full width of the plate or girder.
Bridging
To prevent joists from springing sideways under load (which would
reduce their carrying capacity), they are tied together diagonally by
1 × 3 or 2 × 3 strips, a process called bridging (see Figure 7-6). The
1 × 3 ties are used for small houses, and the 2 × 3 stock on larger
work. Metal bridging may also be used (see Figure 7-7).
Rows of bridging should not be more than 8 feet apart. Bridging
pieces may be cut all in one operation with a miter box, or the
bridging may be cut to fit. Bridging is put in before the subfloor is
laid, and each piece is fastened with two nails at the top end. The
subfloor should be laid before the bottom end is nailed.
A more-rigid (less-vibrating) floor can be made by cutting in solid
2-inch joists of the same depth. They should be cut perfectly square
and a little full (say, 1/16 inch longer than the inside distance between
the joists). First, set a block in every other space, then go back and
put in the intervening ones. This keeps the joists from spreading
and allows the second ones to be driven in with the strain the same
in both directions. This solid blocking is much more effective than
cross bridging (see Figure 7-8). The blocks should be toe nailed, and
not staggered and nailed through the joists.
Headers and Trimmers
The foregoing operations would complete the first-floor framework
in rooms having no framed openings (such as those for stairways,
chimneys, and elevators).
The definition of a header is a short transverse joist that supports the ends of one or more joists where they are cut off at an
Floors, Girders, and Sills 119
Figure 7-6 Metal bridging in place and being installed.
Figure 7-7 Cross bridging
between floor joists made of
1-inch × 3-inch wood.
CROSS BRIDGING
JOIST
CROSS BRIDGING BETWEEN JOISTS
opening. A trimmer is a carrying joist that supports an end of a
header.
Figure 7-9 shows typical floor openings used for chimneys and
stairways. For these openings, the headers and trimmers are set in
place first. The floor joists are installed next. Metal hangers are
available.
120 Chapter 7
Figure 7-8 Solid bridging between joists.
TECO-U-GRIP
JOIST HANGER
TRIMMER
HEADERS
TRIMMER
Figure 7-9 One of many framing fasteners available. These are
joist hangers, but are commonly referred to as Tecos, after the
brand name.
Floors, Girders, and Sills 121
Headers run at right angles to the direction of the joists. They are
doubled. Trimmers run parallel to the joists and are actually doubled
joists. The joists are framed to the headers where the headers form
the opening frame at right angles to the joists. These shorter joists
framed to the headers are called tail beams. The number of headers
and trimmers required at any opening depends upon the shape of
the opening.
Subflooring
With the sills and floor joists completed, it is necessary to install the
subflooring. The subflooring is permanently laid before erecting any
wall framework, since the wall plate rests on it (see Figure 7-10).
This floor is called the rough floor (or subfloor, or deck) and may be
viewed as a large platform covering the entire width and length of the
building. Two layers or coverings of flooring material (subflooring
and finished flooring) are placed on the joists. The subfloor may be
1-inch × 4-inch square-edge stock, 1 × 6 or 1 × 8 shiplap, or 4-foot
× 8-foot sheets of plywood.
PLYWOOD
SUBFLOORING
Figure 7-10 Board subflooring is laid diagonally for greater
strength.
122 Chapter 7
A finished wood floor is in most cases 3/4-inch tongue-and-groove
hardwood (such as oak). Prefinished flooring can also be obtained.
In addition, there are nonwood materials, which will be covered in
detail later in this book.
Summary
A girder is a principal beam extending from wall to wall of a building
to support the joists or floor beams where the distance is too great
for a single span. Girders can be made of wood, which must be
straight and free of knots. Girders are made three, four, five, or six
pieces thick, depending on the load per linear foot and length of the
girder.
A sill is the part of the sidewalls of a house that rests horizontally
upon, and is securely fastened to, the foundation. The sills are the
first part of the framing to be set in place. Therefore, it is important
that the sill be constructed properly and placed properly on the
foundation. There are various types of sills used; which sill depends
on the type of house construction. The size of the sill depends on
the load to be carried and on the spacing of the piers. In some
construction, two sill plates are used, one nailed on top of the other.
After the sill plate and girder have been constructed and installed,
the next operation is to install the floor joists. The joists can be
installed in a variety of ways.
To prevent joists from warping under load (which would reduce
their carrying capacity), they are tied together diagonally with 1 ×
3 or 2 × 3 boards or metal bridging. Bridging is installed before the
subflooring is laid. The subfloor should be laid before the bottom
end is nailed.
After the joists are installed, the subflooring is laid. In most
cases, board subfloor is laid diagonally to give strength and prevent squeaks in the floor. The material generally used for subfloors
is 1 × 6 or 1 × 8 boards, or 4-foot × 8-foot plywood panels.
The finished floor in most cases is 1/2-inch tongue-and-groove
hardwood. To save time and labor, pre-finished flooring can be obtained. Where heavy loads are to be carried on the floor, 2-inch
flooring should be used.
Review Questions
1.
2.
3.
4.
What must be done to align the top edge of floor joists?
What is bridging, and how is it installed?
How should subflooring be laid?
When are headers and trimmers used in floor joists?
Floors, Girders, and Sills 123
5.
6.
7.
8.
9.
10.
What are tail beams?
Why are girders used?
How are sills anchored to the foundation?
Name the various types of sills constructed.
What is the purpose of the sill?
How are engineered girders made?
Chapter 8
Constructing Walls
and Partitions
Constructing walls and partitions involves knowing something
about bracing and working with studs. Partitions must be plumb
and square, while corners must be properly aligned and braced.
Erecting the frame and making it upright and properly braced is
also important in the construction of any building.
Built-Up Corner Posts
Corner posts may be built up in many ways. You can use studding
or larger-sized pieces. Some carpenters form corner posts with two
2-inch × 4-inch studs spiked together to make one piece having a
4 × 4 section. This is suitable for small structures with no interior finish. Figure 8-1 shows various arrangements of built-up posts
commonly used.
INSULATE GAP
FROM INTERIOR
NAILING SURFACES
Figure 8-1 Various ways to build up corner post.
125
126 Chapter 8
Bracing
There are two kinds of permanent bracing. One type is called cut-in
bracing (see Figure 8-2). A house braced in this manner withstood
one of the worst hurricanes ever to hit the eastern seaboard, and
engineers, after an inspection, gave the bracing the full credit for
the survival. The other type of bracing is called plank bracing (see
Figure 8-3). This type is put on from the outside, the studs being
cut and notched so that the bracing is flush with the outside edges
of the studs. This method of bracing is commonly used and is very
effective. Usually bracing is not needed when plywood is used as
sheathing.
Figure 8-2 A 2 x 4 cut between stud bracing. This type of
bracing is called cut-in.
Preparing the Corner Posts and Studding
Studs are cut on a radial-arm saw with a stop clamped to the fence
to ensure that the studs are all the same length.
Erecting the Frame
If the builder is shorthanded, or working alone, a frame can be
crippled together, one member at a time. An experienced carpenter
can erect the studs and toenail them in place with no assistance
whatever. Then the corners are plumbed and the top plates nailed
on from a stepladder. Where enough workers are available, most
Constructing Walls and Partitions 127
PERMANENT BRACE
LET INTO STUDS FLUSH
ON OUTSIDE OF FRAME
OUTSIDE
Figure 8-3 Plank-type bracing.
contractors prefer to nail the sole plates and top plates while the
entire wall is lying on the subfloor. Some even cut all the door and
window openings; after that, the entire gang raises the assembly and
nails it in position. This is probably the speediest of any possible
method, but it cannot be done by only one or two workers. Some
contractors even put on the outside sheathing before raising the wall,
and then use a lift truck or a high-lift excavating machine to raise it
into position.
Framing Around Openings
The openings should be laid out and framed complete. Studding at
all openings must be double to furnish more area for proper nailing
of the trim, and it must be plumb (see Figure 8-4).
It is necessary that some parts of the studs be cut out around
windows or doors in outside walls or partitions. It is imperative to
insert some form of a header to support the lower ends of the top
studs that have been cut off. A member termed a rough sill is located
128 Chapter 8
DEPTH OF HEADER VARIES
WITH SPAN
Figure 8-4 An approved framing for a window opening.
at the bottom of the window openings. This sill serves as a nailer,
but does not support any weight.
Headers
Headers (see Figure 8-5) are of the following two classes:
r Nonbearing headers occur in walls that are parallel with the
joists of the floor above and carry only the weight of the framing immediately above.
r Load-bearing headers occur in walls that carry the end of the
floor joists on plates or rib bands immediately above the openings. They must, therefore, support the weight of the floor or
floors above.
Size of Headers
The determining factor in header sizes is whether they are loadbearing. In general, it is considered good practice to use a double
2 × 4 header placed on edge unless the opening in a nonbearing
partition is more than 3 feet wide. In cases where the trim inside and
outside is too wide to prevent satisfactory nailing over the openings,
it may become necessary to double the header to provide a nailing
base for the trim.
Constructing Walls and Partitions 129
STUDS
DOUBLE HEADER
STUD
DOUBLE STUD
Figure 8-5 Construction of headers when openings over
30 inches between studs appear in partitions or outside walls.
Opening Sizes for Windows and Doors
It is common to frame the openings with dimensions 2 inches more
than the unit dimension. This will allow for the plumbing and leveling of the window. For the rough opening of stock windows, check
the window book from your supplier. For custom windows, the
130 Chapter 8
rough opening should be specified on the drawings. If not, wait
until the windows are on-site to get exact measurements.
Interior Partitions
Interior walls that divide the inside space of the buildings into rooms
or halls are known as partitions. These are made up of studding
covered with plasterboard and plaster, metal lath and plaster, or
drywall (see Figure 8-6).
SILL 2 4
CROSS BEARING
26
PLYWOOD
SUBFLOOR
FLOOR JOIST
Figure 8-6 A method of constructing a partition between two
floor joists.
An interior partition differs from an outside partition in that it
seldom rests on a solid wall. Its support, therefore, requires careful
consideration, making sure it is large enough to carry the required
weight. The various interior partitions may be bearing or nonbearing. They may run at right angles or parallel to the joists upon which
they rest.
Partitions Parallel to Joists
Here the entire weight of the partition will be concentrated on one
or two joists, which perhaps are already carrying their full shares of
the floor load. In most cases, additional strength should be provided.
One method is to provide double joists under such partitions (that
is, to put an extra joist beside the regular ones). Computation shows
that the average partition weighs nearly three times as much as a
single joist should be expected to carry. The usual (and approved)
method is to double the joists under nonbearing partitions. An alternative method is to place a joist on each side of the partition.
Constructing Walls and Partitions 131
Where partitions are placed between and parallel to floor joists,
bridges must be placed between the joists to provide a means of
fastening the partition plate.
BEARER 2 6
CEILING JOIST
11/4 6 NAILING FOR
PLASTER BOARD
2-2 4 PLATE
PLASTER BOARD
PLASTER
STUD 2 4
Figure 8-7 A method of constructing a partition between two
ceiling joists.
Figure 8-7 shows the construction at the top. Openings over
30 inches wide in partitions or outside walls must have heavy headers, as shown in Figure 8-5. The partition wall studs are arranged in
a row with their ends bearing on a long horizontal member called a
bottom plate, and their tops capped with another plate called a top
plate. Double top plates are used in bearing walls and partitions.
The bearing strength of stud walls is determined by the strength of
the studs.
Partitions at Right Angles to Joists
For nonbearing partitions, it is not necessary to increase the size or
number of the joists. The partitions themselves may be braced, but
even without bracing, they have some degree of rigidity.
Engineered Wood and I-Joist Open Metal Web System
The patented SpaceJoist TE combines the best features of an I-joist
and the SpaceJoist open metal-web system. It creates a different
132 Chapter 8
type of floor joist. It can be cut off at the job site, which gives
the installer flexibility. This, combined with the excellent shear and
bearing performance of I-joists, makes the SpaceJoist TE the nearperfect floor joist concept.
The open-web system allows easy passage of ductwork, plumbing, and electrical wiring within the floor. No cutting of plywood
webs is required, and no furring down is necessary to hide mechanicals (see Figure 8-8).
Figure 8-8 Plumbing routed through the metal web of the
joist. (Courtesy of Truswal Systems Corp.)
The webs are made of high-strength galvanized steel. The SpaceJoist TE is built with reliable stress-graded lumber. Each web has
integrally formed metal teeth that are pressed into the sides of the
chords. Each metal web has a patented deep-shape reinforcing rib
that allows the web to be used in compression or tension.
Labor and Material Costs Reduction
On-site, in-place costs are competitive with conventional joist or
truss systems. The SpaceJoist TE design provides a lightweight,
consistent, quality joist for fast placement at any job, dramatically reducing on-site labor costs. On-flat construction gives wide
(21/2-inch) surfaces in order to speed gluing and nailing the floor
Constructing Walls and Partitions 133
sheathing. The joist is custom-engineered using sophisticated computer design software, creating a product that is structurally superior
to conventional framing, far outperforming dimensional lumber. Designs are checked and sealed by registered Professional Engineers
(PEs).
The open-web design and variety of depths allow placement of
12 inches or more of insulation without condensation problems,
and eliminates the need for special air-circulation devices. The designer or architect has freedom to create unique, modern structures, unhampered by the span limitations of conventional floor
joists. The shop-fabricated joists offer a range of depths that provide long, clear spans. The noncombustible webs eliminate a large
portion of the combustible material usually found in the floor. A
variety of fire-endurance assemblies are available to meet fire-rating
requirements.
The newer-type engineered-wood joists serve a number of purposes and improve home safety. It also increases weight-bearing
loads that were not available in conventional joists, as well as offering easy installation. The following illustrations will bear out the
advantages of the latest in construction techniques that add to the
value and soundness of new structures.
Figure 8-9 shows how the portable power handsaw is used to cut
the ends of the joists to fit the span. Figure 8-10 presents a variety
of applications, with depths ranging from 91/4 inches to 153/4 inches.
Figure 8-9 Using a power handsaw to cut joist ends to fit. (Courtesy
of Truswal Systems Corp.)
134
Figure 8-10 Joists mounted over a basement. (Courtesy of Truswal Systems Corp.)
end allows field cutting up
to 12 IN. on both ends to suit on-site needs
• Wide spacing
• Noncombustible high-strength SpaceJoist webs
• Rim board for shear connection, lateral support,
and convenient nailing surface for substrate
• Trimmable
chase openings for easy
placement of heating and air
conditioning duct work
• Wide nailing surfaces
• Interior support detail for multiple-span capability
• Open web design allows easy
installation of pipes, and wiring
• Long clear-span capability
• Large
Constructing Walls and Partitions 135
Figure 8-11 Crawl-space construction on a slab with SpaceJoist TE joists in place. (Courtesy of Truswal Systems Corp.)
4 FT 0 IN. LENGTH 3/4 IN.
REINFORCEMENT
ON BOTH SIDES
TOP MOUNT HANGER
WEB STIFFENER*
RIM BOARD
CLOSURE
LVL
FACE MOUNT HANGER
* Note: If the sides of the hanger do not
extend up to support the top flange
laterally, web stiffeners are required.
RIM BOARD
Attach reinforcement to joist top and
bottom flanges with 8d nails at 6 IN.
o.c. Stagger nails to avoid splitting.
LOAD-BEARING WALL
ABOVE (Must stack
over wall below.)
2 FT 0 IN.
MAXIMUM
Blocking panels may
be required with shear
walls above or below.
OSB Web
2 4 MINIMUM
SQUASH BLOCKS
Cut squash blocks to be 1/16 IN.
greater than depth of joist.
Figure 8-12 Space joist TE details. (Courtesy of Truswal Systems Corp.)
136 Chapter 8
Table 8-1 Maximum Dimensions for Joists in Inches
S
D
H
S
X
W
Y
Z
91/4 in.
11/4 in.
141/4 in.
153/4 in.
D
H
W
S
X
Y
Z (8 in. Z (6 in.
deep) deep)
6.0 in.
7.5 in.
9.9 in.
10.4 in.
3.8 in.
4.7 in.
6.2 in.
7.0 in.
8.1 in.
8.4 in.
11.1 in.
10.3 in.
5.2 in.
6.0 in.
8.0 in.
8.4 in.
6.25 in.
8.25 in.
11.25 in.
12.75 in.
24 in.
24 in.
Varies
Varies
N/A
26 in.
Varies
Varies
26 in.
30 in.
Varies
Varies
Table 8-2 SpaceJoist TE Floor Span Chart
123/4 IN.
7/16 IN.
11/2 IN.
153/4 IN.
21/2 IN.
11/2 IN.
141/4 IN.
7/16 IN.
21/2 IN.
111/4 IN.
11/2 IN.
111/4 IN.
7/16 IN.
21/2 IN.
81/4 IN.
11/2 IN.
91/4 IN.
7/16 IN.
61/4 IN.
21/2 IN.
Spacing
Depth
Deflection 24 in. o.c.
91/4 in. L/480
L/360
111/4 in. L/480
L/360
141/4 in. L/480
L/360
153/4 in. L/480
L/360
14 ft 3 in.
15 ft 9 in.
16 ft 4.5 in.
17 ft 10.5 in.
18 ft 0 in.
18 ft 0 in.
20 ft 0 in.
20 ft 0 in.
19.2 in. o.c.
16 in. o.c.
12 in. o.c.
14 ft 11.5 in.
16 ft 7 in.
17 ft 3 in.
19 ft 4 in.
20 ft 0 in.
21 ft 6 in.
21 ft 6 in.
22 ft 0 in.
15 ft 9 in.
17 ft 4 in.
18 ft 4 in.
20 ft 0 in.
20 ft 10 in.
22 ft 0 in.
22 ft 10 in.
24 ft 0 in.
16 ft 10.5 in.
19 ft 0 in.
19 ft 11 in.
20 ft 0 in.
22 ft 0 in.
22 ft 0 in.
24 ft 0 in.
26 ft 0 in.
40# PSF Live Load. 10# PSF T.C. Dead Load. 5# PSF B.C. Dead Load + 55# PSF
Total Load
Notes:
Up to 12 inches on both ends are trimmable.
Spans shown are based on a floor loading of 40 psf live load and 15 psf dead load
(10 psf T.C., 5 psf B.C.)
Spans shown are out-to-out dimensions and include the bearing length. 13 4-inch
minimum bearing is required at joist ends.
Spans shown assume composite action with single layer of the appropriate
span-rated, glue-nailed wood sheathing for deflection only.
Constructing Walls and Partitions 137
In addition, Figure 8-11 illustrates how the joists are placed in a
crawl-space type of construction.
Table 8-1 shows maximum dimensions for the joists. Table 8-2
shows the floor span and spacing other than 24-inch and 16-inch oncenter. Note the 19.2-inch and 12-inch spacing. Figure 8-12 shows
details of the joists and how they are put to work in a building.
Summary
Bracing is a very important part of outer-wall framing, and there
are generally two types: cut-in and plank.
A carpenter who is working alone can erect each stud and toenail
into the sole plate with no assistance whatsoever. The top plate can
be nailed from a stepladder, after the corners and studs are plumb.
When enough workers are available, most contractors prefer to nail
the sole plates and top plates as the entire wall is lying on the floor
or ground. In many cases, all of the door and window openings are
constructed and nailed in place. Then the wall is raised as one unit
and nailed in position.
Interior walls that divide the inside space into rooms or halls
are generally known as partitions. They are made up of studding
with each joist set 16 inches on-center. Where partitions are to be
placed between and parallel to the floor joists, bridges must be placed
between the joists to provide a means of fastening the partition plate.
Review Questions
1. Why is corner bracing so important?
2. What is the difference between a load-bearing and a nonload-
bearing partition?
3. What is a bearing member?
4. Why should double headers and studs be installed in door and
5.
6.
7.
8.
9.
10.
window openings?
Why are corner-post designs so important?
Name the two kinds of permanent bracing.
How are studs cut?
What is a header?
How are headers classified?
How do you reinforce overloaded floor joists?
Chapter 9
Framing Roofs
As a preliminary to the study of this chapter, you should review
Chapter 17, “Using the Steel Square,” in the book, Audel Carpenters
and Builders Tools, Steel Square, and Joinery (Wiley Publishing,
Inc., 2004) in this series of books (see the Introduction for details
on the series). This tool, which is invaluable to the carpenter in roof
framing, has been explained in detail in that chapter, with many
examples of rafter cutting. Hence, knowledge of how to use the
square is assumed here to avoid repetition.
Types of Roofs
Following are some of the many types of roofs used in construction:
r Shed or lean-to roof—This is the simplest and least-expensive
form of roof and is usually employed for small sheds and outbuildings (see Figure 9-1). It has a single slope.
SMALL PITCH
Figure 9-1 Shed or lean-to
roof used on small sheds or
buildings.
r Gable or pitch roof—This is a very common, simple, and efficient form of roof and is used extensively on all kinds of buildings. It is of triangular section, having two slopes meeting at
the center or ridge and forming a gable (see Figure 9-2). It is
popular because of the ease of construction, relative economy,
and efficiency.
r Gambrel roof—This is a modification of the gable roof, each
side having two slopes (see Figure 9-3).
r Hip roof—A hip roof is formed by four straight sides, all sides
sloping toward the center of the building, and terminating in
a ridge instead of a deck (see Figure 9-4).
r Hip-and-valley roof—This is a combination of a hip roof
and an intersecting gable, so-called because both hip and
valley rafters are required in its construction. There are many
139
140 Chapter 9
Figure 9-2 Gable or pitch roof. (Courtesy of Shetter-Kit, Inc.)
DOUBLE SLOPE
Figure 9-3 Gambrel roof.
Framing Roofs 141
Figure 9-4 Hip roof.
modifications of this roof. Usually the intersection is at right
angles, but it need not be. Either ridge may rise above the other,
and the pitches may be equal or different, thus giving rise to
an endless variety (see Figure 9-5).
r Mansard roof—The straight sides of this roof slope vary
steeply from each side of the building toward the center, and
the roof has a nearly-flat deck on top (see Figure 9-6).
r French or concave mansard roof—This is a modification of
the Mansard roof, its sides being concave instead of straight
(see Figure 9-7).
Roof Construction
The frames of most roofs are made up of timbers called rafters.
These are inclined upward in pairs, their lower ends resting on the
top plate, and their upper ends being tied together with a ridge
board. On large buildings, such framework is usually reinforced by
interior supports to avoid using abnormally large timbers.
The prime objective of a roof in any climate is to keep out water.
The roof must be sloped or otherwise built to shed water. Where
heavy snows cover the roof for long periods, it must be constructed
more rigidly to bear the extra weight. Roofs must also be strong
enough to withstand high winds.
Following are terms used in connection with roofs:
r Span—The span of any roof is the shortest distance between
the two opposite rafter seats. Stated another way, it is the
measurement between the outside plates, measured at right
angles to the direction of the ridge of the building.
r Total rise—The total rise is the vertical distance from the plate
to the top of the ridge.
142 Chapter 9
HIP
VALLEY
90°
UNEQUAL
PITCH
EITHER RIDGE MAY RISE
ABOVE THE OTHER
90°
LESS THAN 90°
Figure 9-5 Various styles of hip-and-valley roofs.
NEARLY FLAT DECKS
STRAIGHT SIDES
Figure 9-6 Mansard roof.
Framing Roofs 143
NEARLY FLAT DECKS
CONCAVE SIDES
Figure 9-7 French or concave Mansard roof.
r Total run—The term total run always refers to the level distance over which any rafter passes. For the ordinary rafter, this
would be one-half the span distance.
r Unit of run—The unit of measurement (1 foot or 12 inches)
is the same for the roof as for any other part of the building.
By the use of this common unit of measurement, the framing
square is employed in laying out large roofs.
r Rise in inches—The rise in inches is the number of inches that
a roof rises for every foot of run.
r Pitch—Pitch is the term used to describe the amount of slope
of a roof.
r Cut of roof—The cut of a roof is the rise in inches and the unit
of run (12 inches).
r Line length—The term line length as applied to roof framing
is the hypotenuse of a triangle whose base is the total run and
whose altitude is the total rise.
r Plumb and level lines—These terms have reference to the direction of a line on a rafter, and not to any particular rafter
cut. Any line that is vertical when the rafter is in its proper
position is called a plumb line. Any line that is level when the
rafter is in its proper position is called a level line.
Rafters
Rafters are the supports for the roof covering and serve in the same
capacity as joists do for the floor or studs do for the walls. Rafters
are sized according to the distance they must span and the load they
must carry.
144 Chapter 9
The carpenter should thoroughly know these various types of
rafters, and be able to distinguish each kind as they are briefly
described. Following are the various kinds of rafters used in roof
construction:
r Common rafter—An example of a common rafter is one extending at right angles from plate to ridge (see Figure 9-8).
RIDGE
R = 90°
COMMON RAFTERS
Figure 9-8 Common rafters.
r Hip Rafter—An example of a hip rafter is one extending diagonally from a corner of the plate to ridge (see Figure 9-9).
r Valley rafter—A rafter that extends diagonally from the plate
to the ridge at the intersection of a gable extension and the
main roof.
r Jack rafter—Any rafter that does not extend from the plate to
the ridge is a jack rafter.
r Hip-jack rafter—A hip-jack rafter extends from the plate to a
hip rafter at an angle of 90◦ to the plate (see Figure 9-9).
r Valley-jack rafter—A valley jack rafter extends from a valley
rafter to the ridge at an angle of 90◦ to the ridge (see Figure
9-10).
r Cripple-jack rafter—A cripple-jack rafter extends from a valley rafter to hip rafter and at an angle of 90◦ to the ridge (see
Figure 9-11).
Framing Roofs 145
RIDGE
TOP CUT
TOP CUT
EXTENDS
DIAGONALLY
TO RIDGE
HIP JACK RAFTER
HIP RAFTERS
CORNER
Figure 9-9 Hip-roof rafters.
90°
VALLEY JACK RAFTER
TOP CUT
BOTTOM CUT
VALLEY RAFTER
Figure 9-10 Valley and valley-jack rafters.
146 Chapter 9
RIDGE
CRIPPLE JACK RAFTERS
TOP CUT
BOTTOM CUT
Figure 9-11 Cripple jack rafters.
r Octagon rafter—An octagon rafter is any rafter that extends from an octagon-shaped plate to a central apex, or
ridgepole.
A rafter usually consists of a main part or rafter proper, and
a short length called the tail, which extends beyond the plate. The
rafter and its tail may be all in one piece, or the tail may be a separate
piece nailed onto the rafter.
Length of Rafter
The length of a rafter may be found in several ways:
r By calculation
r By steel framing square (including the multiposition method,
by scaling, and by aid of the framing table)
r By full-scale layout on the deck
Example
What is the length of a common rafter having a run of 6 feet and
rise of 4 inches per foot?
By calculation (see Figure 9-12):
Framing Roofs 147
TER LE
RAF
G
H OF TRIAN
T
G
LEN USE OF
N
OTE
HYP
ON R
M
COM
C
RISE 4 IN.
PER FT RUN
R
AFTE
RUN = 6 FT
B
A
Figure 9-12 Method of finding the length of a rafter by calculation.
The total rise = 6 × 4 = 24 inches = 2 feet.
Since the edge of the rafter forms the hypotenuse of a right triangle
(whose other two sides are the run and rise) then the length of the
rafter (see Figure 9-12) is calculated as follows:
√
√
√
= run2 + rise2 = 62 + 22 = 40 = 6.33 feet.
Practical carpenters would not consider it economical to find
rafter lengths in this way because it takes too much time and there
is a chance of error. It is to avoid both objections that the framing
square has been developed.
With steel framing square:
The steel framing square considerably reduces the mental effort
and chances of error in finding rafter lengths. An approved method
of finding rafter lengths with the square is with the aid of the rafter
table included on the square for that purpose. However, some carpenters may possess a square, which does not have rafter tables. In
such case, the rafter length can be found either by the multiposition
method (see Figure 9-13), or by scaling (see Figure 9-14). In either
of these methods, the measurements should be made with care because, in the multiposition method, a separate measurement must
be made for each foot run with a chance for error in each measurement.
Problem 1
Lay off the length of a common rafter having a run of 6 feet and a
rise of 4 inches per foot. Locate a point A on the edge of the rafter,
leaving enough stock for a lookout, if any is used. Place the steel
148 Chapter 9
TER
RAF
4th
3rd
2nd
1st
6th
GTH
LEN
5th
G
F
E
D
RAFTER
C
12
RISE 4 IN. PER FT OF RUN
4
B
A
RUN 6 FT
Figure 9-13 Multi-position method of finding rafter length.
LENGTH PER FT RUN
23
22
21
INCH
"
LENGTH COMMON
"
"
RAFTERS PER
101 RAFTER
"
"
FOOT RUN
22
RISE PER FT
21
3
12.3_6
20
8
10
12
14.4_2
15
19.2_0
15.6_2
16.9_7
18
21.6_3
16
20.0_0
20
19
TOTAL LENGTH 6 FT- 311⁄12 IN.
FEET-INCHES
AND TWELFTHS
RAFTERS
3
1
12
12
12
12
12
12
12
PITCH
4 1/6
6 1/4
8 1/3
10 5/12
12 1/2
15 5/8
18 3/4
4
44
4
4
5
5
6
7
2
22
5
9
2
7
4
2
6
13.4_1
4
12.6_4
5
7
8
9
6
11
10
6
5
5
6
6
7
8
9
3
RUN
LENGTH
3
3
1
7
0
2
2
6
0 10
0
1
0
2
6
6
6
7
7
8
9
10
COMMO
3 11
8
6
6
2
9
9
5 10
3
7
9 10
4
Figure 9-14 Rafter-table readings of two well-known makers
of steel framing squares.
Framing Roofs 149
12 (ON SQUARE)
4
3
6
9
12
A
12.65
Figure 9-15 Method of finding rafter length by scaling.
framing square so that division 4 coincides with A, and 12 registers
with the edge of B. Evidently, if the run were 1 foot, distance AB
thus obtained would be the length of the rafter per foot run. Apply
the square six times, for the 6-foot run, obtaining points C, D, E,
F , and G. The distance AG, then, is the length of the rafter for a
given run.
Figure 9-14 shows readings of rafter tables of two well-known
makes of squares for the length of the rafter in the preceding example, one giving the length per foot run, and the other the total length
for the given run.
Problem 2
Given the rise per foot in inches, use two squares, or a square and
a straightedge scale (see Figure 9-15). Place the straightedge on the
square to be able to read the length of the diagonal between the
rise of 4 inches on the tongue and the 1-foot (12-inches) run on
the body as shown. The reading is a little more than 12 inches. To
find the fraction, place dividers on 12 and at point A (see Figure
9-16). Transfer to the hundredths scale and read .65, (see Figure
9-17), making the length of the rafter 12.65 inches per foot run,
which for a 6-foot run is as follows:
12.65 × 6
= 6.33 feet.
12
150 Chapter 9
Figure 9-16 Reading the
straightedge in combination with
the carpenter’s square.
11
12
A
LENGTH OF RAFTER FOR 6 FT RUN
6 = 6.33 FT
_______
= 12.65
12
.65
100 DTHS.
0
1/4
1/2
3/4
1
Figure 9-17 Method of reading hundredths scale.
Problem 3
To find the total rise and run given in feet, let each inch on the
tongue and body of the square equal 1 foot. The straightedge should
be divided into inches and twelfths of an inch so that on a scale, 1
inch = 1 foot. Each division will, therefore, equal 1 inch. Read
the diagonal length between the numbers representing the run and
rise (12 and 4), taking the whole number of inches as feet, and the
fractions as inches. Transfer the fraction with dividers and apply the
hundredths scale, as was done in Problem 2 (see Figure 9-16 and
Figure 9-17).
In estimating the total length of stock for a rafter having a tail,
the run of the tail or length of the lookout must, of course, be
considered.
Framing Roofs 151
Rafter Cuts
All rafters must be cut to the proper angle or bevel at the points
where they are fastened and, in the case of overhanging rafters, also
at the outer end. The various cuts are known as:
r Top or plumb
r Bottom, seat, or heel
r Tail or lookout
r Side or cheek
Common Rafter Cuts
All of the cuts for the various types of common rafters are made
at right angles to the sides of the rafter (that is, not beveled, as in
the case of jacks). Figure 9-18 shows various common rafters from
which the natures of these various cuts are seen.
TOP OR PLUMB CUT
RISE
COMMON RAFTERS
12
RUN
SINGLE BOTTOM OR SEAT CUT
PLATE
Figure 9-18 Various common rafters illustrating types and
names of cuts; showing why one side of the square is set at
12 in laying out the cut.
In laying out cuts from common rafters, one side of the square
is always placed on the edge of the stock at 12 (see Figure 9-18).
This distance 12 corresponds to 1 foot of the run. The other side of
the square is set with the edge of the stock to the rise in inches per
foot run. This is virtually a repetition of Figure 9-13, but it is very
152 Chapter 9
S
FLUSH
(NO TAIL)
R
N
TAIL
N
R
M
(A) Flush (no tail).
(B) Full tail.
SEPARATE
TAIL
(C) Separate tail (reduced tail),
curved or straight.
HEEL CUT
Figure 9-19 Various forms of common rafter tails.
important to understand why one side of the square is set to 12 for
common rafters (that is, not simply to know that 12 must be used).
On rafters having a full tail (see Figure 9-19B), some carpenters do
not cut the rafter tails, but wait until the rafters are set in place so
that they may be lined and cut while in position. Certain kinds of
work permit the ends to be cut at the same time the remainder of
the rafter is framed.
The method of handling the square in laying out the bottom and
lookout cuts is shown in Figure 9-20. In laying out the top or plumb
cut, if there is a ridge board, one-half of the thickness of the ridge
must be deducted from the rafter length. If a lookout or a tail cut is
to be vertical, place the square at the end of the stock with the rise
and run setting (as shown in Figure 9-20), and scribe the cut line LF.
Lay off FS equal to the length of the lookout, and move the square
up to S (with the same setting) and scribe line MS. On this line, lay
Framing Roofs 153
S
RISE
RUN
6
9
12
4
5
R
12
RAFTER
M
4
F
HORIZONTAL
L
S
VERTICAL
N
R
5
6
9
12
4
F
LOOK OUT
M
L
S
F
R
M
N
BIRD’S MOUTH
L
Figure 9-20 Method of using the square in laying out the lower
or end cut of the rafter.
off MR, the length of the vertical side of the bottom cut. Now apply
the same setting to the bottom edge of the rafter, so that the edge of
the square cuts R, and scribe RN, which is the horizontal sideline
of the bottom cut. In making the bottom cut, the wood is cut out
to the lines MR and RN. The lookout and bottom cuts are shown
made in Figure 9-19B, RN being the side that rests on the plate, and
RM the side that touches the outer side of the plate.
Hip and Valley Rafter Cuts
The hip rafter lies in the plane of the common rafters and forms
the hypotenuse of a triangle, of which one leg is the adjacent common rafter, and the other leg is the portion of the plate intercepted
between the feet of the hip and common rafters (see Figure 9-21).
154 Chapter 9
1/2 SPAN
PORTION OF PLATE
12
A
RU
N
16
.97
OF
OR
HI
P
17
RA
FT
ER
45°
12
B
C
COMMON RAFTER
FTER
SE
R
P
HI
HIP
UN OF
17
A
ON RA
ER
FT
RA
PLATE
COMM
HY
R
RAFTE
45°
ER
C
OF N
N MO
RU OM
C
12
NU
TE
PO
PLUMB LINE
PLAN OR HORIZONTAL PROJECTION
OF CENTER LINES
FT
RA
B
PORTION OF PLATE
INTERCEPTED
Figure 9-21 View of hip and common rafters in respect to each
other.
Framing Roofs 155
Problem
In Figure 9-21, take the run of the common rafter as 12, which may
be considered as 1 foot (12 inches) of the run, or the total run of
12 feet (half the span). Now, for 12 feet, intercept on the plate the
hip run inclined to 45◦ to the common run, as in the triangle ABC.
Thus:
AC2 =
AB2 + BC2 =
122 + 122
= 16.97, or approximately 17
Therefore, the run of the hip rafter is to the run of the common
rafter as 17 is to 12. Accordingly, in laying out the cuts, use figure
17 on one side of the square and the given rise in inches per foot
on the other side. This also holds true for top and bottom cuts of
the valley rafter when the plate intercept AB = the run BC of the
common rafter.
The line of measurement for the length of a hip and valley rafter
is along the middle of the back or top edge, as on common and jack
rafters. The rise is the same as that of a common rafter, and the run
of a hip rafter is the horizontal distance from the plumb line of its
rise to the outside of the plate at the foot of the hip rafter (see Figure
9-22).
In applying the source for cuts of hip or valley rafters, use the
distance 17 on the body of the square in the same way as 12 was
used for common rafters. When the plate distance between hip and
common rafters is equal to half the span or run of the common
rafter, the line of run of the hip will lie at 45◦ to the line of the
common rafter (see Figure 9-21).
The length of a hip rafter (as given in the framing table on the
square) is the distance from the ridge board to the outer edge of the
plate. In practice, deduct from this length one-half the thickness of
the ridge board, and add for any projection beyond the plate for
the eave. Figure 9-23A shows the correction for the table length of
a hip rafter to allow for a ridge board, and Figure 9-23B shows
the correction at the plate end that may or may not be made as in
Figure 9-24.
The table length, as read from the square, must be reduced an
amount equal to MS. This is equal to the hypotenuse (ab) of the
little triangle abc, which in value equals
2
ac2 + bc = ac2 × (half thickness of ridge)2 .
R
TE
RA
F
R
RISE PER 12 IN. RUN OF
COMMON SAME AS PER
17 IN. RUN OF HIP RAFTER
M
ON
TE
AF
R
IP
CO
M
H
12 IN.
12
17
12 IN.
17 IN.
RUN OF COMMON RAFTER
RUN OF HIP RAFTER
Figure 9-22 Hip and common rafters shown in the same plane.
This illustrates the use of 12 for the common rafter and 17 for
the hip rafter.
P
HI
S
NG
TH
M
OF
TH
NG E
LE IDG
IN R R
N
IO FO
T
C W
DU LO
EY
RE AL
LL
VA TER
TO
OR F
P RA
HI
b
a
b
E
LE
OF
ON GTH
I
T
EC EN
RR LE L
O
B
C A
T
BL
TA
M
S
COMMON RAFTER
TAIL
E
BL H
TA GT P
N
I
LE F H
O
45°
c
BOTTOM
CUT
a c
HI
P
PLAN
PLATE
(A)
HIP
SIDE VIEW
(B)
Figure 9-23 Correction in table for top cut to allow for half
thickness of ridge board.
156
Framing Roofs 157
TABLE LENGTH
OF VALLEY
TAIL
F
b
L
(+) CORRECTION OF
TABLE LENGTH
c
a
ER
FT
A
YR
LE
L
VA
PLATE
OF R
EW FTE
I
V RA
DE Y
SI LLE
VA
BOTTOM CUT
Figure 9-24 Side view of valley rafter showing bottom and seat
cut at top plate.
In ordinary practice, take MS as equal to half the thickness of
the ridge. The plan and side view of the hip rafter shows the table
length and the correction MS, which must be deducted from the table
length so that the sides of the rafter at the end of the bottom cut will
intersect the outside edges of the plate. The table length of the hip
rafter (as read on the framing square) will cover the span from the
ridge to the outside cover a of the plate, but the side edges of the hip
intersect the plates at b and c. The distance that a projects beyond
a line connecting bc or MS must be deducted (that is, measured
backward toward the ridge end of the hip). In making the bottom
cut of a valley rafter, it should be noted that a valley rafter differs
from a hip rafter in that the correction distance for the table length
must be added instead of subtracted, as for a hip rafter. A distance
MS was subtracted from the table length of the hip rafter (see Figure
9-23B), and an equal distance (LF) was added for the valley rafter
(see Figure 9-24).
After the plumb cut is made, the end must be mitered outward
for a hip (see Figure 9-25) and inward for a valley (see Figure 9-26)
158 Chapter 9
HIP
OUTWARD MITER
TAIL CUT
DOTTED LINES INDICATE
SHEATHING
Figure 9-25 Flush hip-rafter miter cut.
INWARD MITER TAIL CUT
VA
LLE
Y
DOTTED LINES
SHEATHING
Figure 9-26 Flush valley-rafter miter cut.
Framing Roofs 159
TOP CUT
FULL-TAIL HIP
SIDE CUT
FULL-TAIL (CORNER)
MITER CUT
TAIL CUT
SEAT CUT
TOP CUT
FULL-TAIL VALLEY
FULL-TAIL (ANGLE)
MITER CUT
SEAT OR
BOTTOM CUT
SIDE CUT
Figure 9-27 Full-tail hip and valley rafters showing all cuts.
to receive the fascia. A fascia is the narrow vertical member fastened
to the outside ends of the rafter tails. The miter cuts are shown with
full tails in Figure 9-27, which illustrates hip and valley rafters in
place on the plate.
Side Cuts of Hip and Valley Rafters
These rafters have a side or cheek cut at the ridge end. In the absence
of a framing square, a simple method of laying out the side cut for
a 45◦ hip or valley rafter is as follows.
Measure back on the edge of the rafter from point A of the top
cut (see Figure 9-28). Distance AC is equal to the thickness of the
rafter. Square across from C to B on the opposite edge, and scribe
line AB, which gives the side cut. FA is the top cut, and AB is the side
cut. Here A, the point from which half the thickness of the rafter is
measured, is seen at the top end of the cut. This rule does not hold
for any angle other than 45◦ .
Backing of Hip Rafters
By definition, the term backing is the bevel on the top side of a
hip rafter that allows the roofing boards to fit the top of the rafter
without leaving a triangular hole between it and the back of the
roof covering. The height of the hip rafter (measured on the outside
surface vertically upward from the outside corner of the plate) will be
the same as that of the common rafter measured from the same line,
whether the hip is backed or not. This is not true for an unbacked
valley rafter when the measurement is made at the center of the
timber.
160 Chapter 9
SIDE OR CHEEK CUT
EY
THICKNESS
OF RAFTER
L
AL
P
HI
V
OR
45°
C
C
B
D
A
A
RIDGE
B
THICKNESS
OF RAFTER
F
PLUMB CUT
Figure 9-28 A method of obtaining a side cut of 45◦ hip or
valley rafter without aid of a framing table.
RIDGE
COMMON RAFTER
A
O
E
RIS
SE
RI
B
F
E
N
J
M
H
D
G
O
N
J
WOOD TO BE CUT AWAY
(SOLID BLACK SECTIONS)
J
N
M
SECTION OF RAFTER
S
O
O
C
Figure 9-29 Graphical method of finding length of rafters and
backing of hip rafters.
Framing Roofs 161
Figure 9-29 shows the graphical method of finding the backing of
hip rafters. Let AB be the span of the building, and OD and OC the
span of two unequal hips. Lay off the given rise as shown. Then DE
and CF are the lengths of the two unequal hips. Take any point, such
as G on DE, and erect a perpendicular cutting DF at H . Revolve
GH to J (that is, make HJ = GH), draw NO perpendicular to OD
and through H . Join J to N and O, giving a bevel angle NJO,
which is the backing for rafter DE. Similarly, the bevel angle NJO
is found for the backing of rafter CF.
Jack Rafters
There are several kinds of jack rafters, and they are distinguished
by their relation with other rafters of the roof. These various jack
rafters are known (see Figure 9-30) as follows:
RIDGE
VALLEY RAFTER
CRIPPLE RAFTERS
HIP RAFTERS
COMBINED HIP JACK
AND COMMON RAFTER
PLATE
COMMON
RAFTERS
VALLEY JACK RAFTERS
HIP JACK RAFTERS
COMBINED HIP JACK AND COMMON RAFTER
BOTTOM CUT
TOP CUTS
Figure 9-30 A perspective view of hip and valley roof showing
the various kinds of jack rafters, and enlarged detail of combined hip-jack and common rafters showing cuts.
r Hip jacks—Rafters that are framed between a hip rafter and
the plate.
162 Chapter 9
r Valley jacks—Rafters that are framed between the ridge and a
valley rafter.
r Cripple jacks—Rafters that are framed between hip and valley
rafters.
The term cripple is applied because the ends or feet of the rafters
are cut off (the rafter does not extend the full length from ridge
to plate). From this point of view, a valley jack is sometimes erroneously called cripple. It is virtually a semi-cripple rafter, but confusion is avoided by using the term cripple for rafters framed between
the hip and valley rafters.
Jack rafters are virtually discontinuous common rafters. They
are cut off by the intersection of a hip or valley (or both) before
reaching the full length from plate to ridge. Their lengths are found
in the same way as for common rafters (the number 12 being used
on one side of the square and the rise in inches per foot run on the
other side). This gives the length of jack rafter per foot run, and is
true for all jacks (hip, valley, and cripple).
In actual practice, carpenters usually measure the length of hip
or valley jacks from the long point to the ridge, instead of along
the center of the top, with no reduction being made for one-half the
diagonal thickness of the hip or valley rafter. Cripples are measured
from long point to long point, with no reduction being made for the
thickness of the hip or valley rafter.
Because no two jacks are of the same length, various methods of
procedure are employed in framing, including the following:
r Beginning with shortest jack
r Beginning with longest jack
r Using framing table
Shortest-Jack Method
Begin by finding the length of the shortest jack. Take its spacing
from the corner, measured on the plates, which, in the case of a 45◦
hip, is equal to the jack’s run. The length of this first jack will be
the common difference that must be added to each jack to get the
length of the next longer jack.
Longest-Jack Method
Where the longest jack is a full-length rafter (that is, a common
rafter), first find the length of the longest jack, then count the spaces
between jacks and divide the length of the longest jack by the number
of spaces. The quotient will be the common difference. Then frame
Framing Roofs 163
the longest jack and make each jack shorter than the preceding jack
by this common difference.
Framing-Table Method
On various steel squares, there are tables giving the length of the
shortest jack rafters corresponding to the various spacings (such as
16, 20, and 24 inches) between centers for the different pitches. This
length is also the common difference and thus serves for obtaining
the length of all the jacks.
Example
Find the length of the shortest jack or the common difference in the
length of the jack rafters, where the rise of the roof is 10 inches
per foot and the jack rafters are spaced 16 inches between centers;
also, when spaced 20 inches between centers. Figure 9-31 shows
the reading of the jack table on the square for 16-inch centers, and
Figure 9-32 shows the reading on the square for 20-inch centers.
10 IN. RISE PER FT
23
22
21
20
LENGTH OF MAIN RAFTERS PER FOOT RUN
" HIP OR VALLEY "
"
"
"
DIFFERENCE IN LENGTH OF 16 INCHES CENTERS
"
"
"
" 2 FEET
"
SIDE CUT OF JACKS USE THE MARKS ^ ^ ^ ^
****
" " HIP OR VALLEY "
"
22
21
20
19
19
12
11
16 95
78
25
94
18
17
16
20
21
32
10
10
28
22
704
56
8 7⁄8
10 1⁄5
15
19
20
31
9
62
70
83
24
9 1⁄4
10 3⁄8
8
LENGTH SHORTEST JACK 16 IN. CENTER
Figure 9-31 Square showing table for shortest jack rafter at
16 inches on center.
Jack-Rafter Cuts
Jack rafters have top and bottom cuts that are laid out the same as
for common rafters, and side cuts that are laid out the same as for a
hip rafter. To lay off the top or plumb cut with a square, take 12 on
the tongue and the rise in inches (of common rafter) per foot run on
the blade, and mark along the blade (see Figure 9-33). The following
example illustrates the use of the framing square in finding the side
cut.
Example
Find the side cut of a jack rafter framed to a 45◦ hip or valley for
a rise of 8 inches per foot run. Figure 9-34 shows the reading on
the jack side-cut table of the framing square, and Figure 9-35 shows
the method of placing the square on the timber to obtain the side
164 Chapter 9
LENGTH SHORTEST JACK
1 7
6
46
__
__
1802
72
__
__
2080
12
18
__
2475
1 6
1 5
INCH
DIF IN
''
LENGTH OF JACKS
''
''
20 INCH CENTERS
''
''
1 6
1 5
10 IN. RISE PER FT RUN
1 4
3
20 5/8
4
21 1/8
8
24
10
26
15
32
16
33 3/8
1 4
6
22 3/8
1 3
DIF IN
12
28 1/4
LENGTH OF JA
18
36
24 INCH CENT
1 2
Figure 9-32 Square showing table for shortest jack rafter at
20 inches on center.
12
RISE IN IN. PER FT OF RUN
12
8
F
TOP OR
PLUMB CUT
L
Figure 9-33 Method of finding plumb and side cuts of jack
framed to 45◦ hip or valley.
cut. It should be noted that different makers of squares use different
setting numbers, but the ratios are always the same.
Method of Tangents
The tangent value is made use of in determining the side cuts of jack,
hip, or valley rafters. By taking a circle with a radius of 12 inches,
the value of the tangent can be obtained in terms of the constant of
the common rafter run.
Considering rafters with zero pitch (see Figure 9-36), if the common rafter is 12 feet long, the tangent MS of a 45◦ hip is the same
length. Placing the square on the hip, setting to 12 on the tongue
Framing Roofs 165
JACK SIDE CUT
11
4
25 1/4
10
31 1/4
16
40
6
26 7/8
12
34
12
43 1/4
10
FIGURES GIVEN
SIDE CUT
10
`
INCH
''
''
''
''
''
OF JACKS
9
8 IN. RISE PER FT RUN
9
8
4
8 99 1/4
10
8
10 12 10 13
16
15
10 16 9 15
3
7 3/4
8
6
9
10
FIGURES GIVEN
12
12
SIDE CUT
OF HIP ON
17
18
10
18
VALLEY RAFTER
7
6
Figure 9-34 A framing square showing readings for side cut of
jack corresponding to 8-inch rise per foot run.
7
6
INCH
3 4
,, 7, 7 1/8 7, 7 1/4
,,
8 10
,,
9,10 13,15
9
R
SIDE CUT
10
L
JACK
F
PLUMB CUT
Figure 9-35 Method of placing a framing square on jack to lay
off side cut for an 8-inch rise.
and 12 on the body will give the side cut at the ridge when there is
no pitch (at M), as shown in Figure 9-37. Placing the square on the
jack with the same setting numbers (12, 12) as at S, will give the
face cut for the jack when framed to a 45◦ hip with zero pitch (that
is, when all the timbers lie in the same plane).
Octagon Rafters
On an octagon (or eight-sided) roof, the rafters joining the corners
are called octagon rafters and are a little longer than the common
rafter and shorter than the hip or valley rafters of a square building of the same span. Figure 9-38 shows the relation between the run
166 Chapter 9
PLATE
S
45
TANGENT 12 FT (=RUN)
ZERO PITCH
°H
IP
12 FT
M
COMMON RAFTER
Figure 9-36 A roof with zero pitch shows the common rafter
and the tangent as being the same length.
ZERO PITCH
12
12
12-12
(45° HIP)
12
M
12
R 45°
FACE CUT
S
FACE CUT
12
12
Figure 9-37 Zero-pitch square 45◦ roof shows application of
the framing square to give side cuts at the ridge.
Framing Roofs 167
F
TANGENT
5 FT
RUN COMMON RAFTER 12
12
R
GON
CTA 13
NO
S
3
ER 1
AFT
RU
L M
17
DE
SI
N
GO
TA
OC
OF
Figure 9-38 Details of an octagon roof showing relation in
length between common and octagon rafters.
of an octagon and a common rafter as being as 13 is to 12. That
is, for each foot run of a common rafter, an octagon rafter would
have a run of 13 inches. Hence, to lay off the top or bottom cut of
an octagon rafter, place the square on the timber with the 13 on the
tongue and the rise of the common rafter per foot run on the blade
(see Figure 9-39). Figure 9-40 shows the method of laying out the
top and bottom cut with the 13-rise setting.
The length of an octagon rafter may be obtained by scaling the
diagonal on the square for 13 on the tongue and the rise in inches
per foot run of a common rafter, and multiplying by the number of
feet run of a common rafter. The principle involved in determining
the amount of backing of an octagon rafter (or any other polygon) is
the same as for hip rafters. The backing is determined by the tangent
of the angle whose adjacent side is one-half the rafter thickness and
whose angle is equivalent to one-half the center angle.
Trusses
There are definite savings in material and labor requirements with
preassembled wood roof trusses. They make truss framing an
168 Chapter 9
COMMON RAFTER
OCTAGON RAFTER
12
RISE
13
12
13
Figure 9-39 For equal rise, the run of octagon rafters is 13
inches, to 12 inches for the common rafters.
RI
SE
13
SE
13
F
L
RI
M
OCTAGON RAFTER
BOTTOM CUT
S
TOP CUT
Figure 9-40 Method of laying-off bottom and top cuts of an
octagon rafter with a square using the 13 rise setting.
effective means of cost reduction in small-dwelling construction (see
Figure 9-41). In a 26-foot × 32-foot dwelling, for example, the use
of trusses can result in a substantial cost savings and a reduction in
use of lumber of almost 30 percent as compared with conventional
rafter-and-joist construction. In addition to cost savings, roof trusses
Framing Roofs 169
offer other advantages of increased flexibility for interior planning,
and added speed and efficiency in site erection procedures. Today,
most homes built in the United States use trusses. Not only may the
framing lumber be smaller in dimension than in conventional framing, but trusses may also be spaced 24 inches on center as compared
to the usual 16-inch spacing of rafter and joist construction.
16
DOUBLE 1 6
2 4 TOP CHORD
16
DOUBLE 1 6
24
16
16
2 4 BOTTOM CHORD
Figure 9-41 Wood roof truss for small dwellings.
Trusses are built of stress-rated lumber fastened together with
gang nail plates. The clear span of truss construction permits use
of nonbearing partitions so that it is possible to eliminate the extra
top plate required for bearing partitions used with conventional
framing. It also permits a small floor girder to be used for floor
construction since the floor does not have to support the bearing
partition and help carry the roof load.
Aside from direct benefits of reduced cost and savings in material and labor requirements, roof trusses offer special advantages
in helping to speed up site erection and overcome delays caused by
weather conditions. These advantages are reflected not only in improved construction methods but also in further reductions in cost.
With preassembled trusses, a roof can be put over the job quickly
to provide protection against the weather. Trusses are made and delivered to the job site by specialty manufacturers who also provide
design services.
Dormers
The term dormer is given to any window protruding from a roof.
The general purpose of a dormer may be to provide light or to add
to the architectural effect.
In general construction, the following are three types of dormers:
r Dormers with flat-sloping roofs, but with less slope than the
roof in which they are located (see Figure 9-42)
170 Chapter 9
DORMER RAFTER
DOUBLE
HEADER
HIP RAFTER
LOCATION OF CEILING
FURRING IF USED
PLYWOOD
SHEATHING
PLATE
STUD
CORNER
POST
STUD
RAFTER
RAFTER
TYING
DOUBLE
TRIMMER
STUD
JOISTS
PLATE
METHOD OF BRACING ROOF
WHERE RAFTERS ARE AT
RIGHT ANGLES TO JOISTS
Figure 9-42 Detail view of a flat-roof dormer.
r Dormers with roofs of the gable type at right angles to the
roof
r A combination of these types, which gives the hip-type dormer
(see Figure 9-43)
When framing the roof for a dormer window, an opening is provided in which the dormer is later built. As the spans are usually
short, light material may be used.
Framing Roofs 171
DOUBLE
HEADER
DORMER
RAFTER
RIDGE
JACK
RAFTER
RAFTER
RAFTER
CORNER
POST
LOCATION
OF CEILING
FURRING IF USED
PLATE
DOUBLE
TRIMMER
STUD
STUD
PLYWOOD
SHEATHING
PLATE
STUD
Figure 9-43 Detail view of a hip-roof dormer.
Summary
There are numerous forms of roofs and an endless variety of roof
shapes. The frames of most roofs are made up of timbers called
rafters. The terms used in connection with roofs are span, total rise,
total run, unit of run, rise in inches, pitch, cut of roof, line length,
and plumb and level lines.
Rafters are the supports for the roof covering and serve in the
same manner, as do joists for floors or do studs for the walls. Rafters
are constructed from ordinary 2-inch × 6-inch, 2 × 8, or 2 × 10 lumber, spaced 16 to 24 inches on center. Various kinds of rafters used in
roof construction are common, hip, valley, jack, and octagon. The
length of a rafter may be found in several ways (by calculation, with
a steel framing square, or with the aid of a framing table).
Definite savings in material and labor with preassembled wood
roof trusses make truss framing an effective means of cost reduction in small buildings. In addition to cost savings, roof trusses
172 Chapter 9
offer advantages of increased flexibility for interior planning, and
added speed and efficiency in site-erection procedures. Light-wood
trusses have been developed that permit substantial savings because
they may be spaced 24 inches on center, as compared to the usual
16-inch spacing.
Review Questions
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Name the various kinds of rafters used in roof construction.
Name the various terms used in connection with roofs.
What is preassembled truss roofing?
What are some advantages of preassembled truss roofing?
What are jack rafters and octagon rafters?
How can the length of a rafter be found?
Where would an octagon rafter be used?
List three common rafter tails.
Why would you have need for a flush hip rafter miter cut?
Where is the bird’s eye on a rafter?
Jack rafters are virtually
common rafters.
Why is the term cripple applied to a rafter?
Chapter 10
Framing Chimneys and
Fireplaces
Although the carpenter is ordinarily not concerned with the building
of the chimney, it is necessary to be acquainted with the methods
of framing around it (see Figure 10-1). Many contemporary homes
have pre-fabricated fireplaces installed with their own set of instructions included for the carpenter and the crew.
The following minimum requirements are recommended:
r No wooden beams, joists, or rafters should be placed within
2 inches of the outside face of a chimney. No woodwork
should be placed within 4 inches of the back wall of any
fireplace.
r No studs, furring, lathing, or plugging should be placed against
any chimney or in the joints thereof. Wooden construction
should be set away from the chimney, or the plastering should
be directly on the masonry, on metal lathing, or on noncombustible furring material.
r The walls of fireplaces should never be less than 8 inches thick
if brick, or 12 inches if stone.
Prefabricated Fireplaces
A minimum amount of framing is necessary for prefabricated fireplaces (see Figure 10-2). They are placed on the slab or on the prepoured spot in the case of a basement in the house. Some use brick
or tile on the floor underneath the fireplace wood-burning section.
Wood, of course, must be kept at a distance from the chimney’s path
up to the roof and into its enclosure on the roof.
The fireplace being installed in Figure 10-3 is sitting on concrete
blocks and will have a gas-fed piece of pipe with holes along the top
to furnish an ignition for logs laid on top of it. This one came with
firebrick inside the fire chamber. These have dampers that are easily
operated. The damper can control or stop the escape of room-heat
when not in use.
Contemporary Design
Figure 10-4 shows an example of a very contemporary fireplace. This
type is one that is usually installed after the house has been built and
173
174 Chapter 10
TILE FLUE
LINING
TILE FLUE
LINING
DOUBLE
HEADER
DOUBLE
HEADER
DOUBLE
TRIMMER
JOIST
(A)
DOUBLE
TRIMMER
(B)
EXTERIOR WALL
EXTERIOR WALL
HEARTH
DOUBLE HEADER
DOUBLE TRIMMER
DOUBLE HEADER
(D)
(C)
DOUBLE
TRIMMER
EXTERIOR WALL
DOUBLE
HEADER
(E)
DOUBLE
TRIMMER
Figure 10-1 Framing around chimneys and fireplaces: (A) roof
framing around chimney; (B) floor framing around chimney;
(C) framing around chimney above fireplace; (D) floor framing
around fireplace; (E) framing around concealed chimney above
fireplace.
lived in for some time. The rocks (encased in a box) provide some
protection from flying embers. The damper can be easily controlled
by the butterfly knob at the junction of the fireplace with the exhaust
tube. In this case, the fireplace is more a piece of furniture than a
functional source of heat.
Framing Chimneys and Fireplaces 175
Figure 10-2 Framed-in prefab fireplace sitting on bricks. Note
the double exhaust pipe where once the house would have had
a solid masonry construction. This type is primarily for decoration. However, it can be used for heat if necessary.
176 Chapter 10
Figure 10-3 Prefab fireplace sitting on concrete blocks.
Framing Chimneys and Fireplaces 177
Figure 10-4 A contemporary fireplace, usually installed after
a house is built.
Summary
The minimum requirements recommended for fireplaces include the
following:
r No wooden beams, joists, or rafters should be placed within
2 inches of the outside face of a chimney.
r No studs, furring, lathing, or plugging should be placed against
any chimney or in the joints thereof.
r The walls of fireplaces should never be less than 8 inches thick
if brick, or 12 inches if stone.
A minimum amount of framing is necessary for prefabricated
fireplaces. They are placed on the slab or on the prepoured spot in
the case of a basement in house. Some prefabricated fireplaces use
brick or tile on the floor underneath the fireplace’s wood-burning
section.
178 Chapter 10
Many freestanding fireplaces (in contemporary surroundings) are
nothing more than a piece of furniture and are chosen for their ability
to contribute to the decor of the room.
The floor around a contemporary fireplace may be covered with
small rocks to protect from flying sparks. Of course, this isn’t necessary if the floor is tiled, or is made of brick or concrete.
Review Questions
1. What type of fireplace is used today in modern house-building?
2. How far should wooden beams, joists, or rafters be kept from
the outside face of a chimney?
3. The walls of fireplaces should never be less than
inches
thick if brick, or 12 inches if stone.
4. Why are double trimmers or double headers needed around a
fireplace?
5. Where is the hearth located in a fireplace installation?
Chapter 11
Roofs and Roofing
A roof includes the roof cover (the outer layer that protects against
rain, snow, and wind), the sheathing to which it is fastened, and the
framing (rafters) that supports the whole structure.
The term roofing (or roof cover) refers to the outermost part of a
roof. Because of its exposure, roofing usually has a relatively limited
life. It is made to be readily replaceable. It may be made of many
different materials, including the following:
r Wood—These are usually in the form of shingles that are uniform, machine-cut; or hand-cut shakes (see Figure 11-1).
Figure 11-1 Wood shakes handsomely top this lovely home.
Wood shingles, which give a uniform appearance, are also available. (Courtesy of Scholz Homes, Inc.)
r Metal or aluminum—This simulates other kinds of roofing.
r Slate—This may be the natural product, or rigid manufactured
slabs, often of cement-asbestos.
r Tile—This is a burned clay or shale product. Several standard
types are available.
r Built-up covers of asphalt- or tar-impregnated felts—These
may have moppings of hot tar or asphalt between the plies
179
180 Chapter 11
and a mopping of tar or asphalt overall. However, with tarfelt roofs, the top is usually covered with embedded gravel or
crushed slag.
r Roll roofing—As the name implies, this is marketed in rolls
containing approximately 108 square feet. Each roll is usually
36 inches wide and may be plain or have a coating of colored
mineral granules. The base is a heavy asphalt impregnated felt.
r Asphalt shingles—These are usually in the form of strips with
two, three, or four tabs per unit. These shingles are asphalt,
with the surface exposed to the weather heavily coated with
mineral granules. Because of their fire-resistance, cost, and
reasonably good durability, this is the most popular roofing
material for residences (see Figure 11-2). Asphalt shingles are
available in a wide range of colors, including back and white.
Figure 11-2 Asphalt shingles being installed on a wood-shingle
roof. Asphalt is now the most popular roofing.
r Glass-fiber shingles—These are made partly of a glass-fiber
mat that is waterproof and partly of asphalt. Like asphalt shingles, glass-fiber shingles come with self-sealing tabs and carry
a Class-A fire-resistance warranty (see Figure 11-3). For the
do-it-yourselfer, they may be of special interest because they
are lightweight, about 220 pounds per 100 square feet (see
Figure 11-4).
Figure 11-3 Glass-fiber shingles are light in weight and have a
high fire-resistance rating. (Courtesy of Owens-Corning)
Figure 11-4 These shingles look like slate, but they are actually
glass fiber. (Courtesy of Owens-Corning)
181
182 Chapter 11
Slope of Roofs
The slope of the roof is a factor in the choice of roofing materials and
in the method used to put them in place. The lower the pitch of the
roof, the greater is the chance of wind and water getting under the
shingles. Interlocking cedar shingles resist this wind prying better
than the standard asphalt shingles. For roofs with less than a 4-inch
slope per foot, do not use standard asphalt. Roll roofing can be
used with pitches down to 2 inches. For very low-pitched slopes,
use built-up roofing.
Aluminum strip roofing virtually eliminates the problem of wind
prying, but it is noisy. Most homeowners object to the noise during
a rainstorm. Even on porches, this noise is often annoying inside the
house.
Spaced roofing boards are sometimes used with cedar shingles as
an economy measure and to allow an air space for ventilation.
For drainage, most roofs should have a certain amount of slope.
Roofs with tar-and-gravel coverings are theoretically satisfactory
when built level, but standing water may ultimately do harm. If you
can avoid a flat roof, do so. Level roofs are common on industrial
and commercial buildings.
Selecting Roofing Materials
Roofing materials are commonly sold by dealers or manufacturers
based on quantities sufficient to cover 100 square feet. This quantity
is commonly termed one square. When ordering roofing material, it
will be well to make allowance for waste (such as in hips, valleys,
and starter courses). This applies in general to all types of roofing.
The slope of the roof and the strength of the framing are the first
determining factors in choosing a suitable covering. If the slope is
slight, there will be danger of leaks with a wrong kind of covering,
and excessive weight may cause sagging, which is unsightly and adds
to the difficulty of keeping the roof in repair. The cost of roofing
depends largely on the type of roof to be covered. A roof having
ridges, valleys, dormers, or chimneys will cost considerably more to
cover than one having a plain surface. Very steep roofs are also more
expensive than those with a flatter slope, but most roofing materials
last longer on steep grades than on low-pitched roofs. Frequently,
nearness to supply centers permits the use (at lower cost) of the more
durable materials instead of the commonly lower-priced, shorterlived ones.
In considering cost, you should keep in mind maintenance,
repair, and the length of service expected from the building. A
Roofs and Roofing 183
permanent structure warrants a good roof, even through the first
cost is somewhat high. When the cost of applying the covering is
high in comparison with the cost of the material, or when access to
the roof is hazardous, the use of long-lived material is warranted.
Unless insulation is required, semi-permanent buildings and sheds
are often covered with low-grade roofing.
Frequently, the importance of fire resistance is not recognized,
and at other times it is wrongly stressed. It is essential to have a covering that will not readily ignite from glowing embers. The building
regulations of many cities prohibit the use of certain types of roofing in congested areas where fires may spread rapidly. Underwriters
Laboratories, Inc., has grouped many different kinds and brands of
roofing in classes from A to C according to the protection offered
against spread of fire. Class A is the best.
The appearance of a building can be changed materially by using
the various coverings in different ways. Wood shingles and slate are
often used to produce architectural effects. The roofs of buildings
in a farm group should harmonize in color, even though similarity
in contour is not always feasible.
All coal-tar pitch roofs should be covered with a mineral coating,
because when fully exposed to the sun, they deteriorate. Observation
has shown that, in general, roofing materials with light-colored surfaces absorb less heat than those with dark surfaces. Considerable
attention should be given to the comfort derived from a properly
insulated roof. A thin uninsulated roof gives the interior little protection from heat in summer and cold in winter. Discomfort from
summer heat can be lessened to some extent by ventilating the space
under the roof. None of the usual roof coverings have any appreciable insulating value. If it is necessary to reroof, consideration
should be given to the feasibility of installing extra insulation under
the roofing.
Roll Roofing
Roll roofing (see Figure 11-5) is an economical cover especially
suited for roofs with low pitches. It also is sometimes used for
valley flashing instead of metal. Roll roofing has a base of heavy,
asphalt-impregnated felt with additional coatings of asphalt, which
are dusted to prevent adhesion in the roll. The weather surface may
be plain or covered with fine mineral granules. Many different colors are available. One edge of the sheet is left plain (no granules)
where the lap cement is applied. For best results, the sheathing must
be tight (preferably 1 × 6 tongue-and-groove, or plywood). If the
sheathing is smooth, with no cupped boards or other protuberance,
184 Chapter 11
CEMENT
SECOND SHEET
FIRST SHEET
Figure 11-5 First and second strips of roll roofing installed.
the slate-surfaced roll roofing will withstand a surprising amount of
abrasion from foot traffic, although it is not generally recommended
for that purpose. Windstorms are the most relentless enemy of roll
roofing. If the wind gets under a loose edge, almost certainly a section will be blown off.
The Built-Up Roof
A built-up roof is constructed of sheathing paper, a bonded base
sheet, perforated felt, asphalt, and surface aggregates (see Figure
11-6). The sheathing paper comes in 36-inch-wide rolls and has approximately 500 square feet per roll. It is a rosin-size paper and is
used to prevent asphalt leakage to the wood deck. The base sheet
ASPHALT
SHEATHING PAPER
BASE SHEET
PERFORATED FELT
Figure 11-6 Sectional plan of a built-up roof.
AGGREGATE
Roofs and Roofing 185
is a heavy, asphalt-saturated felt that is placed over the sheathing
paper. It is available in 1-, 11/2-, and 2-square rolls. The perforated felt is one of the primary parts of a built-up roof. It is saturated with asphalt and has tiny perforations throughout the sheet.
The perforations prevent air entrapment between the layers of felt.
The perforated felt is 36 inches wide and weighs approximately
15 pounds per square. Asphalt is also one of the basic ingredients of a
built-up roof. There are many different grades of asphalt, but the
most common are:
r Low melt
r Medium melt
r High melt
r Extra-high melt
Prior to the application of the built-up roof, the deck should be
inspected for soundness. Wood board decks should be constructed
of 3/4-inch seasoned lumber. Any knotholes larger than 1 inch should
be covered with sheet metal. If plywood is used as a roof deck, it
should be placed at right angles to the rafters and be at least 1/2 inch
in thickness.
The first step in the application of a built-up roof is the placing
of sheathing paper and base sheet. The sheathing paper should be
lapped 2 inches and secured with just enough nails to hold it in place.
The base sheet is then placed with 2-inch side laps and 6-inch end
laps. The base sheet should be secured with 1/2-inch-diameter–head
galvanized roofing nails placed 12 inches on center on the exposed
lap. Nails should also be placed down the center of the base sheet.
The nails should be placed in two parallel rows 12 inches apart.
Each sheet is then coated with a uniform layer of hot asphalt.
While the asphalt is still hot, layers of roofing felt are placed.
Each sheet should be lapped 19 inches, leaving an exposed lap of
17 inches.
Once the roofing felt is placed, a gravel stop is installed around
the deck perimeter (see Figure 11-7). Two coated layers of felt should
extend 6 inches past the roof decking where the gravel stop is to be
installed. When the other plies are placed, the first two layers are
folded over the other layers and mopped in place. The gravel stop
is then placed in a 1/8-inch-thick bed of flashing cement and securely
nailed every 6 inches. The ends of the gravel stop should be lapped
6 inches and packed in flashing cement.
After the gravel stop is placed, the roof is flooded with hot asphalt and the surface aggregate is embedded in the flood coat. The
186 Chapter 11
AGGREGATE
GRAVEL STOP
ASPHALT
ROOF CEMENT
NAILS - 3 IN. O.C.
Figure 11-7 Illustrating the gravel stop.
aggregates should be hard, dry, opaque, and free of any dust or foreign matter. The size of the aggregates should range from 1/4 inch
to5/8 inch. When the aggregate is piled on the roof, it should be
placed on a spot that has been mopped with asphalt. This technique
ensures proper adhesion in all areas of the roof.
Wood Shingles
The better grades of wood shingles are made of cypress, cedar, and
redwood and are available in lengths of 16 and 18 inches and thicknesses at the butt of 5/16 inch and 7/16inch, respectively. They are packaged in bundles of approximately 200 shingles in random widths
from 3 to 12 inches.
An important requirement in applying wood shingles is that each
shingle should lap over the two courses below it, so that there
will always be at least three layers of shingles at every point on
the roof. This requires that the amount of shingle exposed to the
weather (the spacing of the courses) should be less than one-third
the length of the shingle. Thus in Figure 11-8, 51/2 inches is the
maximum amount that 18-inch shingles can be laid to the weather
and have an adequate amount of lap. This is further shown in
Figure 11-9A.
If the shingles are laid more than one-third of their length to the
weather, there will be a space, as shown by MS in Figure 11-9B,
where only two layers of shingles will cover the roof. This is
Roofs and Roofing 187
51
/2 I
N.
51
/2 I
N.
18
51
/2 I
IN
.
N.
51
/2 I
N.
LAP 1 1/2 IN.
Figure 11-8 Section of a shingle roof illustrating the amount
of shingle that may be exposed to the weather, as governed by
the lap.
.
18
IN
.
1 /2
P
IN
E
1
LA
.
N
8I
.
1 /2
IN
AC
SP
.
1 /2
IN
6
S
51
/2
IN
.
1
ER
OV
b
M
a
61
/2
IN
.
5
(A) Correct lap.
(B) Incorrect lap.
Figure 11-9 The amount of lap is an important factor in applying wood shingles.
188 Chapter 11
objectionable, because if the top shingle splits above the edge of
the shingle below, water will leak through. The maximum spacing
to the weather for 16-inch shingles should be 47/8 inches, and for
18-inch shingles should be 51/2 inches. Strictly speaking, the amount
of lap should be governed by the pitch of the roof. The maximum
spacing may be followed for roofs of moderate pitch, but for roofs
of small pitch, more lap should be allowed, and for a steep pitch
the lap may be reduced somewhat, but it is not advisable to do so.
Wood shingles should not be used on pitches less than 4 inches per
foot.
Table 11-1 shows the number of square feet that 1000 shingles
(five bundles) will cover for various exposures. This table does not
allow for waste on hip and valley roofs.
Table 11-1 Space Covered by 1000 Shingles
Exposure to Weather, in inches
Area Covered, in Sq. Ft
41/4
41/2
43/4
5
51/2
6
118
125
131
138
152
166
Shingles should not be laid too close together, for they will swell
when wet, causing them to bulge and split. Seasoned shingles should
not be placed with their edges nearer than 3/16 inches when laid. It
is advisable to soak the bundles thoroughly before opening.
Great care must be used in nailing wide shingles. When they are
more than 8 inches in width, they should be split and laid as two
shingles. The nails should be spaced such that the distance between
them is as small as is practical, thus directing the contraction and
expansion of the shingle toward the edges. This lessens the danger of
wide shingles splitting in or near the center and over joints beneath.
Shingling is always started from the bottom and laid from the eaves
or cornice up.
There are various methods of laying shingles, the most common
known as:
r The straightedge
r The chalk-line
r The gage-and-hatchet
Roofs and Roofing 189
The straightedge method is one of the oldest. A straightedge having a width equal to the spacing to the weather or the distance
between courses is used. This eliminates measuring, it being necessary only to keep the lower edge flush with the lower edge of the
course of shingles just laid. The upper edge of the straightedge is
then in line for the next course. This is considered the slowest of the
three methods.
The chalk-line method consists of snapping a chalk line for each
course. To save time, two or three lines may be snapped at the same
time, making it possible to carry two or three courses at once. It is
faster than the straightedge method, but not as fast as the gage-andhatchet method.
The gage-and-hatchet method is extensively used in western
states. The hatchet used is either a lathing or a box-maker’s hatchet
(see Figure 11-10). Figure 11-11 shows hatchet gages used to measure the space between courses. The gage is set on the blade at a
distance from the hatchet poll equal to the exposure desired for the
shingles.
Nail as close to the butts as possible if the nails will be well
covered by the next course. Only galvanized shingle nails should be
used. The third shingle nail is slightly larger in diameter than the
third common nail, and has a slightly larger head.
(A) Lathing hatchet.
(B) Box-maker's hatchet.
Figure 11-10 Hatchets used in shingling.
190 Chapter 11
CORRUGATED
FACE
GAUGE
GAUGE
(A) Adjustable type.
(B) Fixed type.
Figure 11-11 Shingling hatchets and gages.
Hips
The hip is less likely to leak than any other part of the roof, because
the water runs away from it. However, since it is so prominent, the
work should be well done. Figure 11-12 shows the method of cutting
shingle butts for a hip roof. After courses 1 and 2 are laid, the top
corners over the hip are trimmed off with a sharp shingling hatchet
kept keen for that purpose. Shingle 3 is trimmed with a butt cut so
as to continue the straight line of courses, and again on dotted line
4, so that shingle A, of the second course, squares against it. This
process is repeated from side to side, each alternately lapping at the
hip joint. When gables are shingled, this same method may be used
up the rake of the roof if the pitch is moderate to steep. It cannot be
effectively used with flat pitches. The shingles used should be ripped
to uniform width.
For best construction, metal shingles should be laid under the hip
shingles (see Figure 11-13). These metal shingles should correspond
in shape to that of the hip shingles. They should be at least 7 inches
wide and large enough to reach well under the metal shingles of the
course above, as at w. At a, the metal shingles are laid so that the
lower end will just be covered by the hip shingle of the course above.
Valleys
In shingling a valley, first a strip of sheet metal or roll roofing (ordinarily 20 inches wide) is laid in the valley. Figure 11-14 illustrates an
open-type valley. Here the dotted lines show the aluminum or other
Roofs and Roofing 191
4
A
3
2
1
Figure 11-12 Hip-roof shingling.
A
W
Z
Figure 11-13 Method of installing metal shingles under
wooden shingles.
192 Chapter 11
SHINGLE LATH OR RIB
TIN
VA
L
L EY
RIBS
Figure 11-14 Method of shingling a valley.
material used as flashing under the shingles. If the pitch is above 30◦ ,
then a width of 16 inches is sufficient; if flatter, the width should be
more. In a long valley, its width between shingles should increase
in width from 1 inch at the top to 2 inches at the bottom. This is
to prevent ice or other objects from wedging when slipping down.
The shingles taper to the butt (the reverse of the hip) and need no
reinforcing, because the thin edge is held and protected from splitting
off by the shingle above it. Care must always be taken to nail the
shingle nearest the valley as far from it as practical by placing the
nail higher up.
Asphalt Shingles
Asphalt shingles are made in strips of two, three, or four units or tabs
joined together, as well as in the form of individual shingles. When
laid, strip shingles furnish practically the same pattern as individual
shingles. Both strip and individual types are available in different
shapes, sizes, and colors to suit various requirements.
Asphalt shingles must be applied on slopes having an incline
of 4 inches or more to the foot. Before the shingles are laid, the
underlayment should be placed. The underlayment should be 15pound asphalt-saturated felt. This material should be placed with
Roofs and Roofing 193
2-inch side laps and 4-inch end laps (see Figure 11-15). The underlayment serves two purposes:
r It acts as a secondary barrier against moisture penetration.
r It acts as a buffer between the resinous areas of the decking
and the asphalt shingles.
4 IN. END LAP
2 IN. SIDE LAP
UNDERLAYMENT
DRIP EDGE
SHEATHING
FASCIA
Figure 11-15 Application of the underlayment.
A heavy felt should not be used as underlayment. The heavy felt
would act as a vapor barrier and would permit the accumulation of
moisture between the underlayment and the roof deck.
The roof deck may be constructed of well-seasoned 1-inch × 6inch tongue-and-groove sheathing or plywood. The boards should
be secured with two 8d nails in each rafter. Plywood should be placed
with the long dimension perpendicular to the rafters. The plywood
should never be less than 5/8 inch thick.
To efficiently shed water at the roof’s edge, a drip edge is usually installed. A drip edge is constructed of corrosion-resistant sheet
metal. It extends 3 inches back from the roof edge. To form the
drip-edge the sheet metal is bent down over the roof edges.
The nails used to apply asphalt shingles should be hot galvanized nails with large heads, sharp points, and barbed shanks. The
nails should be long enough to penetrate the roof decking at least
3/ inch.
4
To ensure proper shingle alignment, horizontal and vertical chalk
lines should be snapped on the underlayment. It is usually recommended that the lines be placed 10 or 20 inches apart. The first
course of shingles placed is the starter course. This is used to back
194 Chapter 11
up the first regular course of shingles and to fill in the spaces between the tabs. It is placed with the tabs facing up the roof and is
allowed to project 1 inch over the rake and eave (see Figure 11-16).
To ensure that all cutouts are covered, 3 inches should be cut off the
first starter shingle.
CHALKED LINE
RAKE EDGE
INVERTED COURSE
EAVE LINE
Figure 11-16 The starter course.
Once the starter course has been placed, the different courses of
shingles can be laid. The first regular course of shingles should be
started with a full shingle; the second course with a full shingle,
minus one-half a tab; the third course is started with a full shingle
(see Figure 11-17); and the process is repeated. As the shingles are
placed, they should be properly nailed (see Figure 11-18). If a threetab shingle is used, a minimum of four nails per strip should be used.
The nails should be placed 55/8 inches from the bottom of the shingle
and should be located over the cutouts. The nails on each end of the
shingle should be located one inch from the end. The nails should
be driven straight and flush with the surface of the shingle.
UNDERLAYMENT
CHALKED LINE
SHINGLE MINUS ONE TAB
SHINGLE MINUS 1/2 TAB
FULL SHINGLE
Figure 11-17 Application of the starter shingles.
Roofs and Roofing 195
1 IN.
5 5/8 IN.
Figure 11-18 The proper placement of nails.
Figure 11-19 shows two roofers bringing up the air-hose to drive
their stapler in anchoring the shingles to the sheathing. Figure 11-20
shows the mess that can accumulate if the roofers do not properly
dispose of the wrappings of the shingles. This type of environment
can become a safety hazard very quickly. If the wind starts to build
up speed, the paper will create a public-relations nightmare for the
builder as the neighbors start complaining.
If there is a valley in the roof, it must be properly flashed. The two
materials that are most often used for valley flashing are 90-pound
mineral-surfaced asphalt roll roofing or sheet metal. The flashing
Figure 11-19 Roofers pulling up their air hose to continue upward in the application of shingles.
196 Chapter 11
Figure 11-20 Shingle wrappings create a safety hazard and
become unsightly.
is 18 inches in width. It should extend the full length of the valley.
Before the shingles are laid to the valley, chalked lines are placed
along the valley. The chalk lines should be 6 inches apart at the top
of the valley and should widen 1/8 inch per foot as they approach the
eave line. The shingles are laid up to the chalked lines and trimmed
to fit.
Hips and ridges are finished by using manufactured hip and ridge
units, or hip and ridge units cut from a strip shingle. If the unit is
cut from a strip shingle, the two cut
lines should be cut at an angle (see Figure 11-21). This will prevent the projection of the shingle past the overlaid shingle. Each shingle should be
bent down the center so that there
is an equal distance on each side. In
cold weather, the shingles should be
warmed before they are bent. Starting
at the bottom of the hip or at the end
of a ridge, the shingles are placed with
Figure 11-21 Hip shin- a 5-inch exposure. To secure the shingles, a nail is placed on each side of the
gle.
Roofs and Roofing 197
shingle. The nails should be placed 51/2 inches back from the exposed
edge and 1 inch up from the side.
If the roof slope is particularly steep (specifically if it exceeds
60◦ or 21 inches per foot), then special procedures are required for
securing the shingles (see Figure 11-22).
Two other details are worth noting. For neatness when installing asphalt shingles, the courses should meet in a line above
any dormer (see Figure 11-23). In addition, of course, ventilation must be provided for an asphalt roof. All roofs should be
ventilated.
Slate
Slate is not used as much as it once was, but it is still used. The process of manufacture is to split the quarried slate blocks horizontally
to a suitable thickness, and to cut vertically to the approximate sizes
required. The slates are then passed through planers and, after the
operation, are ready to be reduced to exact dimensions on rubbing
beds, or by air tools and other special machinery.
Roofing slate is usually available in various colors and in standard
sizes suitable for the most exacting requirements. On all boarding
to be covered with slate, asphalt-saturated rag felt of certain specified thickness is required. This felt should be laid in a horizontal
layer with joints lapped toward the eaves and at the ends at least
2 inches. A well-secured lap at the end is necessary to hold the
felt in place properly, and to protect the structure until covered
by the slate. In laying the slate, the entire surface of all main and
porch roofs should be covered with slate in a proper and watertight
manner.
The slate should project 2 inches at the eaves and 1 inch at all
gable ends, and should be laid in horizontal courses with the standard 3-inch head lap. Each course should break joints with the preceding one. Slates at the eaves or cornice line should be doubled
and canted 1/4 inch by a wooden cant strip. Slates overlapping sheetmetal work should have the nails so placed as to avoid puncturing
the sheet metal. Exposed nails should be used only in courses where
unavoidable. Neatly fit the slate around any pipes, ventilators, and
so on.
Nails should not be driven in so far as to produce a strain on the
slate. Cover all exposed nails heads with elastic cement. Hip slates
and ridge slates should be laid in elastic cement spread thickly over
unexposed surfaces. Build in, place all flashing pieces furnished by
the sheeting contractor, and cooperate with him or her in doing the
work of flashing. On completion, all slate must be sound, whole,
198
No. 15 felt
Starter strip
ASPHALT ADHESIVE CEMENT INSTALLED
WHEN SHINGLES ARE APPLIED
Three tab − one spot under each tab
Two tab − 2 spots under each tab
No cutout − 3 spots under shingle
Self-sealing
shingle
FOR SLOPES GREATER THAN
60° OR 21 IN. PER FOOT
Drip edge
Roof deck
Figure 11-22 When a roof has a severe slope, special installation procedures are required
for asphalt shingles.
Nail as recommended by
roofing manufacturers–
4-6 nail per shingle
Roofs and Roofing 199
Courses must meet
in line above dormer.
CHALK LINES
Figure 11-23 Arrangement of shingles when there is a
dormer.
and clean, and the roof should be left in every respect tight and a
neat example of workmanship.
Gutters and Downspouts
Most roofs require gutters and downspouts to carry the water
away from the foundation (see Figure 11-24). They are made of
10
14
1
3
2
15
4
5
6
7
9
8
11
DOWNSPOUT
SECTIONS
1. LEFT END CAP
8. END PIECE
2. GUTTER
9. GUTTER SCREEN
3. SPIKE & FERRULE
10. RIGHT END CAP
4. SLIP JOINT
11. ELBOW
5. INSIDE MITRE
12. DOWNSPOUT
6. OUTSIDE MITRE
13. DOWNSPOUT BAND
7. CROSSBAR HANGER
14. STRAINER
12
13
11
15. HIDDEN HANGER
Figure 11-24 Various metal gutter downspouts and fittings. (Courtesy of Billy Penn Gutters)
200 Chapter 11
aluminum, steel, wood, or plastic. In regions of heavy snowfall,
the outer edge of the gutter should be 1/2 inch below the extended
slope of the roof to prevent snow banking on the edge of the
roof and causing leaks. The hanging gutter is best adapted to such
construction.
Downspouts should be large enough to remove the water from
the gutters. A common fault is to make the gutter outlet the same
size as the downspouts. At 18 inches below the gutter, a downspout
has nearly four times the water-carrying capacity of the inlet at the
gutter. Therefore, a good-sized ending to the downspout should be
provided. Wire baskets or guards should be placed at gutter outlets
to prevent leaves and trash from collecting in the downspouts and
causing damage during freezing weather.
The most popular kind of gutter is
made of aluminum. It comes in two
common gages, 0.027 and 0.032, with
the thicker material better, of course.
Standard lengths are 10 feet, and they
are joined by special connectors (see
Figure 11-25) using either sheet-metal
screws or blind rivets (blind rivets are
simplest).
Any connection, however, represents an area that can leak. It is better to get so-called seamless gutter.
Fabricators will custom-cut to fit. You
Figure 11-25 A gutterwill also save installation time. Seamsection connector.
less gutter is commonly 0.032-gage.
Gutters should have the proper slope for good runoff of water—
about 1/2 inch to every 10 feet (see Figure 11-26). Some people make
the mistake of sloping one gutter according to the way the house
10 FT
1/2
IN. DROP IN
10 FT
Figure 11-26 Gutter should slope 1/2 inch per 10 feet.
Roofs and Roofing 201
appears. However, this can lead to errors because a house, although
it may look level, never really is.
Summary
The roof of a building includes the roof cover (which is protection
against rain, snow, and wind), the sheathing (which is a base for
the roof cover), and the rafters (which are the support for the entire
roof structure).
The term roofing refers to the outermost part of the roof. There
are various types of roofing used, such as wood (which generally
is in the form of shingles or shakes), aluminum, tile, roll roofing,
asphalt, and glass fiber.
Various types and styles of flashing are used when a roof connects to any vertical wall (such as chimneys, outside walls, and
so on). Flashing around chimneys and skylights is installed in the
same general manner as for vertical walls. It is generally made from
roll-roofing material, sheet metal, or aluminum bent to fit the contour of the vertical wall. It is essential for sealing joints.
Most roofs require rain gutters and downspouts to carry the water to the sewer or outlet. Gutters and downspouts are usually built
of aluminum. Seamless 0.032 gutter is best. Downspouts should be
large enough to remove the water from the gutters. Much gutter
deterioration is caused by freezing water in low areas, rust, and
restricted sections caused by leaves or other debris.
Review Questions
1. Name various types of roofing material.
2. What is flashing and why is it used?
3. Why can corrugated metal roofs be installed without roof
sheathing?
4. How much coverage in square feet is one square of roofing?
5. What is a drip cap?
6. Why is the slope of the roof a factor in the choice of roofing
7.
8.
9.
10.
material?
True or false, asphalt shingles come in strips.
Where is roll roofing acceptable for use?
What is a built-up roof?
The better grades of wood shingles are made of cypress, cedar,
.
and
Chapter 12
Skylights
A skylight is any window placed in the roof of a building or ceiling
of a room for the admission of light and/or ventilation. Skylights
are essential to lighting and ventilating top floors where roofs are
flat (such as in factories) and where there is not much side lighting.
In the home, they are often placed at the top of stairs or in a room
where no side window is available.
Figure 12-1 shows a simple hinged skylight and detail of the
hinge. The skylight may be operated from below by the control
device, which has an adjustment eye in the support for securing the
hinged sash at various degrees of opening. A skylight is often placed
at the top of a flight of stairs leading to the roof, the projecting
structure having framed in it the skylight and a doorway (see Figure 12-2).
Figure 12-1 Hinged skylight framed into roof.
203
204 Chapter 12
Figure 12-2 View of entrance to roof, or projection framework
containing framed opening for skylight and doorway.
Where fireproof construction is required, skylights are made of
metal. Figure 12-3 shows side-pivoted sash skylights. This is a type of
skylight desirable for engine and boiler rooms where a great amount
of steam and heat is generated. A storm coming in through them
would do little harm if the skylights were thoughtlessly left open. The
sash may be operated separately by pulleys, or all on one adjuster.
The ends may be stationary.
Wire glass should be used for factory skylights so that, if broken,
it will not fall and possibly injure someone below. Wire glass is cast
with the wire netting running through its center and is manufactured
in many styles and sizes.
Skylights are becoming more popular in residential dwellings (see
Figure 12-4). They come double insulated and can be opened for
ventilation. They are set in waterproof frames, which are permanently installed and sealed in the roof. A skylight can often help
Skylights 205
Figure 12-3 Metal fireproof ventilating skylight.
Figure 12-4 Skylight in a residence. It floods dark areas with
light and can even help heat the home.
heat a house. A significant amount of radiant heat from the sun gets
through.
Residential Skylights
The skylight shown in Figure 12-5 is positioned in this home to
provide an openness and free-space look for the entrance, foyer,
and family room. As can be seen, the makeshift ladder placed on
206 Chapter 12
Figure 12-5 Skylight viewed from inside during house construction.
top of the scaffolding makes for a dangerous working condition
when it is located over 25 feet off the floor. The octagonal design is
incorporating (from a design standpoint) a square-domed skylight.
This type of skylight does have the disadvantage of providing extra
heat in the house during summer days. They are also noisy. The noise
Skylights 207
from traffic nearby can be both annoying and tiring. The skylight
pictured does not open. The area from the roof to the ceiling, by
way of the attic, must be finished off with drywall and painted.
The skylight shown in Figure 12-6 is a smaller type that serves
well in a kitchen to make it a lighter and roomier place for cooking
and serving food. This one is fixed. It requires a large light tunnel
to be framed in and drywalled through the attic.
Figure 12-6 Smaller skylight used to brighten up a kitchen
area.
Skylight Maintenance
Condensation may appear on the inner dome surface with sudden temperature changes or during periods of high humidity. These
droplets are condensed moisture. Condensation will evaporate as
conditions of temperature and humidity normalize.
Figure 12-7 shows how light-shaft installations can be used to
present the light from the skylight to various parts of the room
below. Figures 12-8 and 12-9 show how the original installations
are made in houses under construction. Details and basic sizes are
given, along with the roof pitch and slope chart. These will help you
plan the installation from the start.
208
(B) Angled light shaft
(90° to porch pitch)
(C) Tunnel flare light shaft
(shaft flared at head & 90° to ceiling
at sill)
Figure 12-7 Suggested light shaft installations. (Courtesy of Andersen)
(A) Tunnel light shaft
(90° to ceiling on all four sides)
Where a roof window is installed above a flat ceiling, a light shaft will be needed. Typical installations
are shown below. Flaring the shaft will give broader light distribution. Shaft construction by others.
(D) Wide angle light shaft
(flared on all four sides)
Skylights 209
(A) Vertical detail
vent unit
OPTIONAL
WATER DEFLECTOR
12
8
9 IN. FLASHING
APPLY CAULKING
INSULATION
SASH
FRAME
OPERATOR SCREEN
DOUBLE PANE
TEMPERED
HIGH PERFORMANCE
INSULATING GLASS
VAPOR BARRIER
HANDLE
HEAD
6 IN. FLASHING
N.
1 /2 I
PINE
EXTENSION JAMBS
BY OTHERS
3 4I
1/
3 /8 I
N.
HT
EIG T
N H EIGH
O
I
H
S
EN ING
DIM PEN
IT
O
UN GH
U
RO
N.
N.
3 /8 I
DOUBLE PANE
TEMPERED
HIGH PERFORMANCE
INSULATING GLASS
SILL
N.
1 /2 I
SCALE 1 1/2 IN. = 1FT 0 IN.
34°- 8/12 Roof pitch shown. For
complete specifications see
installation instructions.
(B) Horizontal detail
vent unit
6 IN. STEP
FLASHING
3 11/32 IN.
APPLY CAULKING
INSULATION
PINE
EXTENSION JAMBS
BY OTHERS
VAPOR BARRIER
JAMB
JAMB
3/
8
IN.
3/
8
UNIT DIMENSION WIDTH
ROUGH OPENING WIDTH
INCLINE CURB FLASHING
IN.
(C) Vertical detail
vent unit
BATT INSULATION
HEADER
VAPOR BARRIER ROOF ESS
N
THICK
HEAD
1/
2
SILL
BLOCKING
IN. DRYWALL
NING
H OPE
ROUG
T
HEIGH
K
T-BAC
ER SE
HEAD INED BY
M
DETER ICKNESS
TH
ROOF
Figure 12-8 Roof-window vent unit, in place. (Courtesy of Andersen)
210 Chapter 12
(D) Basic sizes
UNIT DIM.
RGH. OPG.
∗
GLASS VENT.
1 FT
9 1/4
IN.
1 FT 10 IN.
15 1/16 IN.
2 FT
5 1/8
IN.
2 FT 5 7/8 IN.
23 IN.
3 FT 5
5/16
IN.
3 FT 6 IN.
(E) Incline curb flashing
rough openings
WHEN INSTALLING UNITS WITH
INCLINE CURB FLASHING USE THESE
ROUGH OPENINGS.
35 3/16 IN.
WIDTH
DIM. A
2 FT 9 1/2 IN.
2 FT 10 1/4 IN.
27 1/8 IN.
UNIT
*Unobstructed glass sizes
shown in inches.
37 3/4 IN.
3 FT 8 3/4 IN.
3 FT 8 1/16 IN.
RW2133V
2133
2144
2944
2957
4144
4157
34 3/4 IN.
21 5/8 IN.
45 1/2 IN.
45 1/2 IN.
29 1/2 IN.
58 3/4 IN.
29 1/2 IN.
45 1/2 IN.
41 3/4 IN.
41 3/4 IN.
58 3/4 IN.
HEADER SET BACK
ROOF
THICKNESS
DIM. C
13/16 IN.
6 1/2 IN.
8 1/2 IN.
1 1/8 IN.
10 1/2 IN.
1 1/2 IN.
12 1/2 IN.
1 13/16 IN.
(F) Roof pitch/slope chart
50 3/4 IN.
4 FT 9 3/4 IN.
4 FT 9 1/16 IN.
RW2144V RW2944V RW4144V
ROOF PITCH
ROOF SLOPE
2/12
9° 26'
14°
18° 26'
22° 37'
26° 34'
30° 15'
33° 41'
36° 52'
39° 48'
42° 30'
45°
49° 24'
59°
70°
80°
3/
12
RW2957V RW4157V
4/12
5/
12
6/
12
7/12
8/
12
9/12
10/12
11/12
12/
12
14/12
20/12
40/12
68/12
Incline curb flashing is recommended for roof installations less than
3/12
HEIGHT
DIM. B
21 5/8 IN.
18 1/2° (4/12 pitch)
to 9° (2/12 pitch) minimum.
roof pitch (14°) shown. For complete specifications see installation instructions.
Figure 12-8 (continued)
If the dome is made of plastic, the outer dome surface may be polished with paste wax for added protection from outdoor conditions.
If it is made of glass, you may want to wash it before installation and
then touch up the finger marks after it is in place. Roofing mastic can
be removed with rubbing alcohol or lighter fluid. Avoid petroleumbased or abrasive cleaners, especially on clear plastic domes. Roof
(A) Vertical detail
stationary unit
12
DOUBLE PANE TEMPERED
HIGH PERFORMANCE
INSULATING GLASS
8
9 IN. FLASHING
FRAME
APPLY CAULKING
INSULATION
VAPOR BARRIER
HEAD
6 IN. FLASHING
SCALE 1 1/2 IN. = 1 FT 0 IN.
PINE
EXTENSION JAMBS
BY OTHERS
T
IGH
HE GHT
N
I
SIO HE
EN NG
IM NI
T D OPE
I
UNIT DIM.
UN UGH
RO
3 FT 5 5/16 IN.
1 FT 10 IN.
2 FT 5 7/8 IN.
3 FT 6 IN.
GLASS STAT*
18 5/16 IN.
26 3/16 IN.
38 7/16 IN.
RW2944S
RW4144S
RW2957S
RW4157S
30 9/16 IN.
34° - 8/12 Roof pitch shown. For
complete specifications see installation
instructions.
2 FT 5 1/8 IN.
RGH. OPG.
2 FT 9 1/2 IN.
SILL
(C) Basic sizes
1 F T 9 1/4 IN.
2 FT 10 1/4 IN.
3/8 IN.
3/8 IN.
41 3/16 IN.
3 FT 8 3/4 IN.
3 FT 8 1/16 IN.
RW2133S
(B) Horizontal detail
stationary unit
54 3/16 IN.
4 FT 9 3/4 IN.
4 FT 9 1/16 IN.
DOUBLE PANE
TEMPERED
HIGH PERFORMANCE
INSULATING GLASS
RW2144S
* Unobstructed glass sizes shown in inches.
STEP FLASHING
CAULK
INSULATION
DRYWALL RETURN
(BY OTHERS)
JAMB
UNIT DIMENSION WIDTH
JAMB
ROUGH OPENING WIDTH
Figure 12-9 Roof-window stationary unit, in place. (Courtesy of Andersen)
Figure 12-10 Skylight installation. (Courtesy of ODL, Inc.)
Skylights 213
inspection should be conducted every two years to determine potential loosening of screws, cracked mastic, and other weatherrelated problems that may result from normal exposure to outdoor
conditions.
Tube-Type Skylights
Newer tube-type skylights can be installed during house construction or added later. They are designed to provide maximum light
throughput from a relatively small unit. They are right for areas
where a larger, standard skylight may not be practical (see Figure 12-10).
Tube-type skylights come in a kit with everything needed, including illustrated instructions for the do-it-yourselfer. They install in a
few hours with basic hand tools. There is no framing, drywalling,
mudding, or painting required. They are available in both 10-inch
and 14-inch diameters and therefore fit easily between 16-inch or
24-inch on-center rafters (see Figure 12-11).
Most people are concerned about skylights because they have
heard of them leaking, especially during the winter with snow piling
up, then melting. The skylight shown in Figure 12-12 has a one-piece
roof flashing that eliminates leaks. Flashing is specific to the roof
type and ensures a perfect fit. The 14-inch skylight spreads light up
to 300 square feet. There is also an electric light kit available that
makes the skylight into a standard light fixture at night and during
dark periods of the day. It is designed to work from a wall switch
and is a UL-approved installation (see Figure 12-13).
Installation
To install a tube-type skylight, follow these steps:
1. Locate the diffuser position on the ceiling.
2. Check the attic for any obstructions or wiring.
3. Locate the position on the roof for flashing and dome. If the
4.
5.
6.
7.
8.
skylight is being installed in new construction, you can make
sure plumbing and electrical take the skylight into consideration during the construction phase.
Measure and cut an opening in the roof.
Loosen shingles and install the flashing. In new construction, it
may be best to install the flashing before shingles are in place.
Insert the adjustable tube.
Attach the dome (see Figure 12-14).
Measure and cut an opening in the ceiling.
214 Chapter 12
(A)
(B)
Figure 12-11 (A) The dome above the roof line; (B) the dome
reflects the sunlight coming from any angle throughout the day
in any season. (Courtesy of ODL, Inc.)
9. Install the ceiling trim ring.
10. Attach the diffuser. In the attic, assemble, adjust, and install
the tubular components. In colder climates, it is necessary to
insulate the tube shaft.
Skylights 215
Figure 12-12 Exploded
view of the skylight. (Courtesy of
SOLAR LENS* DOME
FLASHING (ASPHALT TYPE)
ODL, Inc.)
15-IN. ADJUSTABLE TUBE
WITH REFLECTIVE LINING
20-IN. EXTENSION TUBE
WITH REFLECTIVE LINING
15-IN. ADJUSTABLE TUBE
WITH REFLECTIVE LINING
TUBE RING SEAL
CEILING TRIM RING
LOW-PROFILE DIFFUSER
Figure 12-13 Conversion of
skylight to a light fixture. (Courtesy of
ODL, Inc.)
216 Chapter 12
Figure 12-14 Installation of the skylight.
(Courtesy of ODL, Inc.)
Summary
Skylights are becoming more popular in residential dwellings. Skylights come double insulated, and some can be opened for ventilation.
A skylight is often placed at the top of a flight of stairs leading to
the roof, or in an inside room where no side windows are available.
Skylights may also be used in areas where the sun penetrates the
glass for heating rooms. In some cases, the sun is used to heat water
stored in ceiling tanks.
Review Questions
1.
2.
3.
4.
What are some of the advantages of a skylight?
Why are skylights used in some dwellings?
Where are skylights placed in dwellings?
What are some disadvantages of skylights?
Skylights 217
Where are skylights located?
What makes it easy to install tube-type skylights?
How often should you check the skylight after installation?
How do you clean the mastic off the dome and other parts of
the skylight?
9. How do you protect the plastic dome on the skylight?
10. Why would you want a skylight that opens to the outside?
5.
6.
7.
8.
Chapter 13
Cornice Details
The cornice is that projection of the roof at the eaves that forms a
connection between the roof and the sidewalls. Following are four
general types of cornice construction:
r Box
r Closed
r Wide box
r Open
Box Cornices
The typical box cornice (see Figure 13-1) utilizes the rafter projection
for nailing surfaces for the facia and soffit boards. The soffit provides
a desirable area for inlet ventilators. A frieze board is often used at
the wall to receive the siding. In climates where snow and ice dams
may occur on overhanging eaves, the soffit of the cornice may be
sloped outward and left open 1/4 inch at the facia board for drainage.
SHINGLES
ROOF
FELT
RAFTER
FACIA
BOARD
1/4- IN.
DRAINAGE GAP
SOFFIT BOARD
FRIEZE
BOARD
Figure 13-1 Box-cornice construction.
Closed Cornices
The closed cornice (see Figure 13-2) has no rafter projection. The
overhang consists only of a frieze board and a shingle or crown
219
220 Chapter 13
SHINGLES
FRIEZE
BOARD
ROOF
FELT
RAFTER
SHINGLE
MOLDING
SIDING
Figure 13-2 Closed-cornice construction.
molding. This type is not so desirable as a cornice with a projection,
because it gives less protection to the sidewalls.
Wide Box Cornices
The wide box cornice (see Figure 13-3) requires forming members
called lookouts, which serve as nailing surfaces and supports for the
soffit board. The lookouts are nailed at the rafter ends and are toenailed to the wall sheathing and directly to the studs. The soffit can
be of various materials (such as beaded ceiling, plywood, or bevel
siding). A bed molding may be used at the juncture of the soffit and
frieze. This type of cornice is often used in hip-roofed houses, and
the facia board usually carries around the entire perimeter of the
house.
Open Cornices
The open cornice (see Figure 13-4) may consist of a facia board
nailed to the rafter ends. The frieze is either notched or cut out to fit
between the rafters and is then nailed to the wall. The open cornice is
often used for a garage. When it is used on a house, the roof boards
are visible from below from the rafter ends to the wall line, and
should consist of finished material. Dressed or matched V-beaded
boards are often used.
Cornice Details 221
RAFTER
ROOF FELT
SHINGLES
FACIA
BOARD
LOOKOUT
VENTILATOR
SOFFIT
FRIEZE
BOARD
BED MOLDING
Figure 13-3 Wide cornice construction.
ROOF FELT
SHINGLES
FRIEZE
BOARD
FACIA BOARD
OPEN RAFTER
BED MOLDING
SIDING
Figure 13-4 Open cornice construction.
Cornice Returns
The cornice return is the end finish of the cornice on a gable roof.
The design of the cornice return depends to a large degree on the
rake or gable projection, and on the type of cornice used. In a closed
222 Chapter 13
rake (a gable end with very little projection), it is necessary to use
a frieze or rake board as a finish for siding ends (see Figure 13-5).
This board is usually 11/8 inches thick and follows the roof slope to
meet the return of the cornice facia. Crown molding or other type
of finish is used at the edge of the shingles.
Figure 13-5 Closed cornice
return.
CROWN
MOLDING
FRIEZE BOARD
FACIA
BOARD
CORNER
BOARD
When the gable end and the cornice have some projection (see
Figure 13-6), a box return may be used. Trim on the rake projection
is finished at the cornice return. A wide cornice with a small gable
BOX
RAKE
BOX CORNICE
SLOPE AND
FLASH
Figure 13-6 Box cornice return.
Cornice Details 223
projection may be finished as shown in Figure 13-7. Many variations
of this trim detail are possible. For example, the frieze board at the
gable end might be carried to the rake line and mitered with a facia
board of the cornice. This siding is then carried across the cornice
end to form a return.
SIDING
FRIEZE
BOARD
Figure 13-7 Wide cornice return.
Rake or Gable-End Finish
The rake section is that trim used along the gable end of a house.
Following are three general types commonly used:
r Closed
r Box with a projection
r Open
The closed rake (see Figure 13-8) often consists of a frieze or
a rake board with a crown molding as the finish. A 1-inch ×
2-inch square edge molding is sometimes used instead of the crown
molding. When fiberboard sheathing is used, it is necessary to use a
narrow frieze board that will leave a surface for nailing the siding
into the end rafters.
If a wide frieze is used, nailing blocks must be provided between
the studs. Wood sheathing does not require nailing blocks. The trim
used for a box-rake section requires the support of the projected roof
224 Chapter 13
SHINGLES
Figure 13-8 Closed-end finish
at the rake.
ROOFING
FELT
CANT STRIP
CROWN
MOLDING
FRIEZE BOARD
SIDING
boards (see Figure 13-9). In addition, lookouts or nailing blocks are
fastened to the sidewall and to the roof sheathing. These lookouts
serve as a nailing surface for both the soffit and the facia boards.
The ends of the roof boards are nailed to the facia. The frieze board
is nailed to the sidewall studs, and the crown and bed moldings
complete the trim. The underside of the roof sheathing of the openprojected rake (see Figure 13-10) is generally covered with linerboards (such as 5/8-inch beaded ceiling). The fascia is held in place
by nails through the roof sheathing.
RAKE
SECTION
ROOF
BOARDS
FACIA BOARD
SOFFIT (RAKE)
LOOKOUT BLOCK
BED MOLDING
SHEATHING
Figure 13-9 Box-end finish at the rake.
Summary
The cornice is that part of the roof at the eaves that forms a connection between the roof and sidewalls. There are generally four styles
of cornice construction: box, closed, wide box, and open.
Cornice Details 225
Figure 13-10 Open-end
finish at the rake.
END
RAFTER
FINISH CEILING
CANT
STRIP
FACIA
BOARD
STUD
The box cornice construction generally uses the rafter ends as
a nailing surface for the facia and soffit board. A board called the
frieze board is used at the wall to start the wood siding. Wide box
cornices require framework called lookouts, which serve as nailing
surfaces and support the soffit board. The lookouts are nailed at the
rafter end and nailed at the other end to the wall stud.
On the closed cornice, there is no rafter projection. There is no
overhang, only a frieze board and molding. There is no protection from the weather for the sidewalls with this type of construction.
Review Questions
Name four types of cornice construction.
What is a frieze board?
Explain the purpose of the facia board.
What is the lookout block and when is it used?
What is the soffit board?
The
cornice has no rafter projection.
The
cornice requires forming members called lookouts.
The
cornice may consist of a facia board nailed to the
rafter ends.
9. True or false, the cornice return is the end finish of the cornice
on a gable roof.
10. The
section is that trim used along the gable end of a
house.
1.
2.
3.
4.
5.
6.
7.
8.
Chapter 14
Doors
Doors (both exterior and interior) may be considered sash, flush, or
louver. Flush doors may also be solid core or hollow core.
Manufactured Doors
For all practical purposes, doors can be obtained from the mill in
stock sizes much cheaper than they can be made by hand. Stock
sizes of doors cover a wide range, but those most commonly used
are 2 feet, 4 inches × 6 feet, 8 inches; 2 feet, 8 inches × 6 feet,
8 inches; 3 feet, 0 inches × 6 feet, 8 inches and 3 feet, 0 inches ×
7 feet, 0 inches. These sizes are either 13/8-inches (interior) or
13/4-inches (exterior) thick.
Sash and Paneled Doors
Panel and sash doors have for component parts a top rail, bottom
rail, and two stiles that form the sides of the door (see Figure 14-1).
The rails and stiles of a door are generally mortised-and-tenoned,
the mortise being cut in the side stiles (see Figure 14-2). Top and
bottom rails on paneled doors differ in width, with the bottom rail
being considerably wider. Intermediate rails are usually the same
width as the top rail. Paneling material is usually plywood (which
is set in grooves or dadoes in the stiles and rails), with the molding
attached on most doors as a finish.
Flush Doors
Flush doors are usually perfectly flat on both sides. Solid planks
are rarely used for flush doors. Flush doors are made with solid or
hollow cores with two or more plies of veneer glued to the cores.
Solid-Core Doors
Solid-core doors are made of short pieces of wood glued together
with the ends staggered very much like in brick laying. One or two
plies of veneer are glued to the core. The first section (about 1/8
inch thick) is applied at right angles to the direction of the core, and
the other section, 1/8 inch or less, is glued with the grain vertical. A
3/ -inch strip (the thickness of the door) is glued to the edges of
4
the door on all four sides. Figure 14-3 shows this type of door
construction.
Hollow-Core Doors
Hollow-core doors (which are flush) have wooden grids or other
honeycomb material for the base, with solidwood edging strips on
227
228 Chapter 14
Figure 14-1 Sash door with glazed sash.
RAIL
WEDGE
TENON IN
MORTISE
BLIND MORTISE
STILE
Figure 14-2 Door constructions showing mortise joints.
Doors 229
GLUED SECTION
(CORE)
FINISH
SURFACE
Figure 14-3 Construction of a laminated or veneered door.
all four sides. The face of this type door is usually 3-ply veneer
instead of two single plies. The hollow-core door has a solid block
on both sides for installing doorknobs and to permit the mortising
of locks. The honeycomb-core door is for interior use only.
Louver Doors
This type of door has either stationary or adjustable louvers. It may
be used as an interior door, room divider, or closet door. The louver
door comes in many styles, such as those shown in Figure 14-4.
Installing Mill-Built Doors
A door frame may be constructed in numerous ways. A door frame
consists of the following essential parts (see Figure 14-5):
r Sill
r Threshold
230 Chapter 14
Figure 14-4 Two styles of louver doors.
r Side and top jamb
r Casing
Door Frames
Before the exterior siding is placed on the outside walls, the door
openings are prepared for the frames. To prepare the openings,
square off any uneven pieces of sheathing and wrap heavy building paper around the sides and top. Since the sill must be worked
into a portion of the subflooring, no paper is put on the floor. Position the paper from a point even with the inside portion of the stud
to a point about 6 inches on the sheathed walls, and staple it down.
Outside door frames are constructed in several ways. In morehasty constructions, there will be no door frame. The studs on each
side of the opening act as the frame and the outside casing is applied to the walls before the door is hung. The inside door frame is
constructed the same way as the outside frame.
Doorjambs
Doorjambs are the lining to the framing of a door opening. Casings
and stops are nailed to the jamb, and the door is securely fastened
Doors 231
B
JAM
NES
D LI
EAD
—H
TE
DOT
AP
PC
DRI
GO
N
ASI
DC
HEA
E
RAV
HIT
RC
RA
BS
M
E JA
SID
S
ING
E
SID
CAS
LD
O
ESH
THR
SILL
Figure 14-5 View of a door frame showing the general construction.
by hinges at one side. The width of the jamb will vary in accordance
with the thickness of the walls. Doorjambs are made and set in the
following manner:
1. Regardless of how carefully the rough openings are made, be
sure to plumb the jambs and level the heads when the jambs
are set.
232 Chapter 14
2. Rough openings are usually made 21/2 inches larger each way
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
than the size of the door to be hung. For example, a 2-foot,
8-inch × 6-foot, 8-inch door would need a rough opening of
2 feet, 101/2 inches × 6 feet, 101/2 inches. This extra space
allows for the jamb, the wedging, and the clearance space for
the door to swing.
Level the floor across the opening to determine any variation
in floor heights at the point where the jamb rests on the floor.
Cut the head jamb with both ends square, allowing for the
width of the door plus the depth of both dadoes and a full 3/16
inch for door clearance.
From the lower edge of the dado, measure a distance equal to
the height of the door plus the clearance wanted at the bottom.
Do the same thing on the opposite jamb. Only make additions
or subtractions for the variation in the floor.
Nail the jambs and jamb heads together through the dado into
the head jamb (see Figure 14-6).
Set the jambs into the opening and place small blocks under
each jamb on the subfloor just as thick as the finish floor will
be. This will allow the finish floor to go under the door.
Plumb the jambs and level the jamb head.
Wedge the sides to the plumb line with shingles between the
jambs and the studs, and then nail securely in place.
Take care not to wedge the jambs unevenly.
Use a straightedge 5 to 6 feet long inside the jambs to help
prevent uneven wedging.
Check each jamb and the head carefully. If a jamb is not plumb,
it will have a tendency to swing the door open or shut, depending on the direction in which the jamb is out of plumb.
Door Trim
Door-trim material is nailed onto the jambs to provide a finish between the jambs and the wall material. This is called the casing. Sizes
vary from 1/2 to 3/4 inch in thickness, and from 21/2 to 6 inches in
width. Most casing material has a concave back, to fit over uneven
wall material. In miter work, care must be taken to make all joints
clean, square, neat, and well-fitted. If the trim is to be mitered at the
top corners, a miter box, miter square, hammer, nail set, and block
plane will be needed. Door openings are cased up in the following
manner:
HE
AD
ST
JA
MB
11/2 IN.
Doors 233
SIDE
JAMB
7/8 IN.
OP
Figure 14-6 Details showing upper head-jamb dadoes into side
jamb.
1. Leave a 1/4-inch margin between the edge of the jamb and the
casing on all sides.
2. Cut one of the side casings square and even with the bottom
3.
4.
5.
6.
of the jamb.
Cut the top or mitered end next, allowing 1/4-inch extra length
for the margin at the top.
Nail the casing onto the jamb and set it even with the 1/4-inch
margin line, starting at the top and working toward the bottom.
Nails along the outer edge will need to be long enough to
penetrate the casing and wall stud.
Set all nail heads about 1/8-inch below the surface of the wood.
234 Chapter 14
7. Apply the casing for the other side of the door opening in the
same manner, followed by the head (or top) casing.
Hanging Doors
If flush or sash doors are used, install them in the finished door
opening as described here:
1. Cut off the stile extension (if any) and place the door in the
frame. Plane the edges of the stiles until the door fits tightly
against the hinge side and clears the lock side of the jamb by
about 1/16 inch. Be sure that the top of the door fits squarely
into the rabbeted recess and that the bottom swings free of the
finished floor by about 1/2 inch. The lock stile of the door must
be beveled slightly so that the edge of the door will not strike
the edge of the doorjamb.
2. After the proper clearance of the door has been made, set the
door in position and place wedges as shown in Figure 14-7.
Mark the position of the hinges on the stile and on the jamb
with a sharp pointed knife. The lower hinge must be placed
slightly above the lower rail of the door. The upper hinge of
the door must be placed slightly below the top rail to avoid
cutting out a portion of the tenons of the door rails. There are
three measurements to mark: the location of the hinge on the
jamb, the location of the hinge on the door, and the thickness
of the hinge on both the jamb and the door.
3. Mortise the door butt hinges into the door and frame (see
Figure 14-8). Three hinges are usually used on full-length doors
to prevent warping and sagging.
4. Use the butt as a pattern, mark the dimension of the butts on
the door edge and the face of the jamb. The butts must fit
snugly and exactly flush with the edge of the door and the face
of the jamb. A device called a butt marker can be helpful here.
After placing the hinges and hanging the door, mark off the position for the lock and handle. The lock is generally placed about
36 inches from the floor level. Hold the lock in position on the stile
and mark off with a sharp knife the area to be removed from the
edge of the stile. Mark off the position of the doorknob hub. Bore
out the wood to house the lock, and chisel the mortises clean. After
the lock assembly has been installed, close the door and mark the
jamb for the striker plate.
Doors 235
FRAME
DOOR
CLEARANCE 1/16 IN.
WEDGES
WEDGE
WEDGES
CLEARANCE 1/8 IN.
Figure 14-7 Sizing a door for an opening.
Swinging Doors
Frequently, it is desirable to hang a door so that it opens as you
pass through from either direction, yet remains closed at all other
times. For this purpose, you can use swivel-style spring hinges. This
type of hinge attaches to the rail of the door and to the jamb like an
ordinary butt hinge. Another type is mortised into the bottom rail
of the door and is fastened to the floor with a floor plate. In most
cases, the floor-plate hinge (see Figure 14-9) is best because it will
not weaken and let the door sag. It is also designed with a stop to
hold the door open at right angles, if so desired.
Sliding Doors
Sliding doors are usually used for walk-in closets. They take up very
little space, and they allow a wide variation in floor plans. This type
236 Chapter 14
THICKNESS OF HINGE
Figure 14-8 Marking for hinges.
of door usually limits the access to a room or closet unless the doors
are pushed back into a wall. Very few sliding doors are pushed back
into the wall because of the space and expense involved. Figure 1410 shows a double and a single sliding door track.
Garage Doors
Garage doors are made in a variety of sizes and designs. The principal advantage of any garage door is, of course, that it can be rolled
Doors 237
Figure 14-9 Two kinds of swivel-type spring hinges.
up out of the way. In addition, the door cannot be blown shut by
the wind, and it is not obstructed by snow and ice.
Standard residential garage doors are usually 9 feet × 7 feet for a
single-car garage and 16 feet × 7 feet for a double. Residential-type
garage doors are usually 13/4-inches thick.
When ordering doors for the garage, the following information
should be forwarded to the manufacturer:
r Width of opening between the finished jambs
r Height of the ceiling from the finished floor under the door to
the underside of the finished header
FINISH
238 Chapter 14
7/8 IN.
7/8 IN.
DOOR
Figure 14-10 Two types of sliding-door tracks.
Figure 14-11 Typical 18-foot overhead residential garage door.
Doors 239
(A) Fiberglass.
(B) Steel.
(C) Wood.
Figure 14-12 Three types of garage doors.
r
r
r
r
r
r
r
r
Thickness of the door
Design of the door (number of glass windows and sections)
Material of jambs (they must be flush)
Headroom from the underside of the header to the ceiling, or
to any pipes, lights, and so forth
Distance between the sill and the floor level
Proposed method of anchoring the horizontal track
Depth to the rear from inside of the upper jamb
Inside face width of the jamb buck, angle, or channel
This information applies for overhead doors only. It does not
apply to garage doors of the sliding, folding, or hinged type. Doors
240 Chapter 14
can be furnished to match any style of architecture and may be
provided with suitable size windows if desired (see Figure 14-11).
If your garage is attached to your house, the door often represents
from one-third to one-fourth of the face of your house. Style and
material should be considered to accomplish a pleasant effect with
masonry or wood architecture. Figure 14-12 shows three types of
overhead garage doors that can be used with virtually any kind of
architectural design. Many variations can be created from combinations of raised panels with routed or carved designs (see Figure
14-13). These panels may also be combined with plain raised panels
to provide other dramatic patterns and color combinations.
Figure 14-13 Variations in carved or routed panel designs.
Automatic garage-door openers were once a luxury item. However, recently the price has been reduced and failure minimized to
the extent that many new installations include this feature. Automatic garage-door openers save time and eliminate the need to stop
the car and get out in all kinds of weather. You also save the energy
and effort required to open and close the door by hand.
The automatic door opener is a radio-activated, motor-driven
power unit that mounts on the ceiling of the garage and attaches to
the inside top of the garage door (see Figure 14-14). Electric impulses
from a wall-mounted pushbutton, or radio waves from a transmitter
in your car, start the door mechanism. When the door reaches its
limit of travel (up or down), the unit turns off and awaits the next
Doors 241
Horizontal and vertical reinforcement
is needed for lightweight garage doors
(fiberglass, steel, aluminum, door with
glass panels, etc.).
FINISHED CEILING
Support bracket &
fastening hardware
is required.
Slack in chain tension
is normal when
garage door is closed.
HEADER WALL
EXTENSION SPRING
OR
TORSION SPRING
ACCESS DOOR
DOOR CENTER
SAFETY
REVERSING
SENSOR
FLOOR MUST BE LEVEL
ACROSS WIDTH OF DOOR.
SAFETY REVERSING SENSOR
Figure 14-14 Typical automatic garage-door opener.
(Courtesy of
Stanley Door Corporation)
command. Most openers on the market have a safety factor built in.
If the door encounters an obstruction in its travel, it will instantly
stop, or stop and reverse its travel. The door will not close until the
obstruction has been removed. When the door is completely closed,
it is automatically locked and cannot be opened from the outside,
making it burglar resistant. The unit has a light, which turns on
when the door opens to light up the inside of the garage.
Summary
Most doors (both exterior and interior) are classified as sash, flush,
or louver.
Sash and panel doors are made in many styles. The rails and
stiles are generally mortised-and-tenoned. Top and bottom rails on
paneled doors differ in width, with the bottom rail considerably
wider. The center rail is generally the same width as the top rail.
The panel material is usually plywood, which is set in grooves or
dadoes in the stiles and rails.
Solid-core doors are made of short pieces of wood glued together
with the ends staggered very much like brick laying. Hollow-core
242 Chapter 14
doors have wooden grids or some type of honeycomb material for
the base, with solid wood edging strips on all four sides. Glued to
the cores of these doors are two or three layers of wood veneer,
which make up the door panel. The honeycomb-core door is made
for interior use only.
Review Questions
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Name the various types of doors.
Why are honeycomb-core doors made for interior use only?
What is a doorstop?
When hanging a door, how much clearance should there be at
top, bottom, and sides?
How are solid-core doors constructed?
The rails and stiles of a door are generally
-andtenoned.
The doorframe consists of the following essential parts: sill,
.
threshold, side and top jambs, and
Doorjambs are the
to the framing of a door opening.
What is the door casing?
True or false: most casing material has a convex back.
Chapter 15
Windows
Windows in any building structure not only provide a means for
illuminating the interior, but also provide a decorative touch to the
structure. Following are the three main window types:
r Double-hung
r Casement
r Gliding
There are also awning, bow, and bay windows (see Figure
15-1). Windows consist essentially of two parts:
r Frame
r Sash
(C) Gliding window.
(A) Double hung window.
(B) Casement window.
(D) Awning window.
(F) Bay window.
(E) Bow window.
Figure 15-1 Window types.
The frame is made up of four basic parts: the head, two jambs,
and the sill.
243
244 Chapter 15
Window Framing
The window sash fits into the window frame. It is set into a rough
opening in the wall framing and is intended to hold the sash in place.
Double-Hung Windows
The double-hung window holds two pieces of sash: (an upper and
lower), which slide vertically past each other (see Figure 15-2).
PARTING STRIP
JAMB
BLIND STOP
CASING
CASING
SASH
BEAD
STOP
STOOL
SILL
APRON
PLASTER
SIDING
ROUGH SILL
Figure 15-2 Three-quarter view of window frame.
Windows 245
This type of window has some advantages and some disadvantages.
Screens can be installed on the outside of the window without interfering with its operation. For full ventilation of a room, only
half of the area of the window can be utilized, and any current
of air passing across its face is, to some extent, lost in the room.
Double-hung windows are sometimes more involved in their frame
construction and operation than the casement window. Ventilation
fans and air conditioners can be placed in the window with it partly
closed.
Hinged or Casement Windows
There are two types of casement windows:
r Out swinging
r In swinging
These windows may be hinged at the side, top, or bottom. The
casement window that opens out requires the screen to be located
on the inside. This type of window, when closed, is more efficient
as far as waterproofing. The in-swinging casement windows, like
double-hung windows, are clear of screens, but they are extremely
difficult to make watertight. Casement windows have the advantage
of their entire area being opened to air currents, thus catching a
parallel breeze and deflecting it into a room. Casement windows
are considerably less complicated in their construction than doublehung units are. Sill construction is very much like that for a doublehung window, however, but with the stool much wider and forming
a stop for the bottom rail of the sash. When there are two casement
windows in a row in one frame, they are separated by a vertical
double jamb (called a mullion), or the stiles may come together in
pairs like a French door. The edges of the stiles may be a reverse
rabbet, a beveled reverse rabbet with battens, or beveled astrogals.
The battens and astrogals ensure better weather tightness.
Gliding, Bow, Bay, and Awning Windows
Gliding windows consist of two sashes that slide horizontally right
or left. They are often installed high up in a home to provide light
and ventilation without sacrificing privacy.
Awning windows have a single sash hinged at the top and open
outward from the bottom. They are often used at the bottom of a
fixed picture window to provide ventilation without obstructing the
view. They are popular in ranch homes.
Bow and bay windows add architectural interest to a home. Bow
windows curve gracefully, while bay windows are straight across
246 Chapter 15
the middle and angled at the ends. They are particularly popular in
Georgian-style and Colonial-style homes.
Wood windows are better than metal ones for insulation purposes, simply because metal conducts heat better than wood. Nevertheless, even more important is double-glazing, which contains a
dead air space that inhibits heat escaping (or getting in, should you
have air conditioning). The second pane can be incorporated in the
window (see Figure 15-3) or it can be removable. If you live in an
area where heating costs are very high, consider triple glazing (three
panes of glass with air spaces between). Tinted or reflective glass is
good for warding off the sun’s rays in warmer climates.
Figure 15-3 Insulated glass.
Window Sash
A sash is a framework that holds the glass lights. The lights are
divided by thin strips called muntins. There are two general types of
wood sash: fixed (or permanent) and movable. Fixed window sash
are removable only with the aid of a carpenter. Movable sash may
be of the variety that slide up and down in channels in the frame
Windows 247
(called double-hung). Casement-type sash swing in or out and are
hinged on the sides.
Sash Installation
Place the upper double-hung sash in position and trim off a slight
portion of the top rail to ensure a good fit, and tack the upper sash
in position. Fit the lower sash in position by trimming off the sides.
Place the lower sash in position, and trim off a sufficient amount
from the bottom rail to permit the meeting rails to meet on a level.
In most cases, the bottom rail will be trimmed on an angle to permit
the rail and sill to match inside and outside (see Figure 15-4).
SCRIBED-OFF
Figure 15-4 Marking bottom-rail trim to match sill plate.
Sash Weights
If sash weights are used, remove each sash after it has been properly
cut and sized. Select sash weights equal to one-half the weight of
each sash and place in position in the weight pockets. Measure the
proper length of sash cord for the lower sash and attach it to the
stiles and weights on both sides. Adjust the length of the cord so
that the weight will not strike the pulley or bottom of the frame
when the window is moved up and down. Install the cords and
weights for the upper sash and adjust the cord so that the weights
run smoothly. Close the pockets in the frame and install the blind
stop, parting strip, and bead stop.
There are many other types of window lifts (such as spring-loaded
steel tapes, spring-tension metal guides, and full-length coil springs).
248 Chapter 15
Glazing Sash
The panes of glass (or lights, as they are called) are generally cut
1/ inch smaller on all four sides to allow for irregularities in cutting
8
and in the sash. This leaves an approximate margin of 1/16 inch
between the edge of the glass and the sides of the rabbet. Figure 155 shows two lights or panes of glass in position for glazing. To install
the window glass properly, first spread a film of glazing compound
close to the edge on the inside portion of the glass. After the glass
has been inserted, drive or press in at least two glaziers’ points on
each side (see Figure 15-6).
SIDE OF RABBET
MUNTIN
GLASS
GLAZIERS' POINTS
GLASS
PUTTY
FILM OF PUTTY
1/16 IN.
MARGIN
Figure 15-5 Glaziers’ points, which are removed to replace
broken glass.
When the glass is firmly secured with the glaziers’ points, the
compound (which is soft) is put on around the glass with a putty
knife and beveled (see Figure 15-6). Do not project the compound
beyond the edge of the rabbet so that it will be visible from the other
side.
Figure 15-7 shows double-hung windows, with small panes simulated by having spacers inserted between the two pieces of glass
that make up the window. This way, the windows are easier to
clean, with one piece of glass rather than numerous small panes.
Windows 249
Figure 15-6 Push
glaziers’ points in with
putty knife.
Figure 15-7 Double-hung windows capped off with semicircular stationary “half-moons.”
Note the stationary-type semicircle windows on top to add style to
the double-hung box appearance. Windows of all shapes and sizes
are now available, so architects have great freedom in their design
work.
250 Chapter 15
Shutters
In coastal areas where damaging high winds occur frequently, shutters are necessary to protect large plate-glass windows from being
broken. The shutters are mounted on hinges and can be closed at
a moment’s notice. Throughout the Midwest, shutters are generally
installed for decoration only and are mounted stationary to the outside wall. There are generally two types of shutters: the solid panel
and the slat (or louver) type. Louver shutters can have stationary or
movable slats.
Summary
Many styles and sizes of windows are used in various house designs, but the main ones are double-hung, casement, and gliding. A
window consists generally of two parts: the frame and the sash.
Double-hung windows are made up of three parts: the upper and
lower sash (which slide vertically past each other) and the frame.
Only half of the area of the window can be used for ventilation,
which is a disadvantage.
Shutters serve a purpose near the coastline, but are only decorative in most of the country.
Review Questions
1. Name the various window classifications.
2. What size should the rough opening be for a double-hung
3.
4.
5.
6.
7.
8.
9.
10.
window?
What are some advantages of casement windows?
Name a few advantages in using window shutters.
What are glazier points, and why should they be used when
installing window glass?
Gliding windows consist of two sash that slide
right
and left.
A
is a framework that holds the glass lights.
If sash
are used, remove each sash after it has been
properly cut and sized.
How do you install glazers’ points?
True or false: the panes of glass, or strips, as they are called,
are generally cut 1/8 inch smaller on all four sides.
Chapter 16
Siding
Sheathing is nailed directly to the framework of the building. Its
purpose is to strengthen the building, to provide a base material to which finish siding can be attached, to act as insulation,
and, in some cases, to be a base for further insulation. Some of
the common types of sheathing include fiberboard, wood, and
plywood.
Fiberboard Sheathing
Fiberboard usually comes in 2-foot × 8-foot or 4-foot × 8-foot
sheets that are tongue-and-grooved and generally coated or impregnated with an asphalt material that increases water resistance.
Thickness is normally 1/2 or 25/32 inch, and fiberboard may be
used where the stud spacing does not exceed 16 inches. Fiberboard sheathing should be nailed with 2-inch galvanized roofing
nails or other type of noncorrosive nails. If the fiberboard is used
as sheathing, most builders will use plywood at all corners, in the
same thickness as the sheathing, to strengthen the walls (see Figure 16-1).
Wood Sheathing
Wood wall sheathing can be obtained in almost all widths, lengths,
and grades. Generally, widths are from 6 to 12 inches, with lengths
selected for economical use. Almost all solid-wood wall sheathing
used is 25/32 to 1 inch in thickness. This material may be nailed on
horizontally or diagonally (see Figure 16-2). Wood sheathing is laid
on tight, with all joints made over the studs. If the sheathing is to
be put on horizontally, it should be started at the foundation and
worked toward the top. If the sheathing is installed diagonally, it
should be started at the corners of the building and worked toward
the center or middle.
Diagonal sheathing should be applied at a 45◦ angle. This method
of sheathing adds greatly to the rigidity of the wall and eliminates the need for corner bracing. It also provides an excellent
tie to the sill plate when it is installed diagonally. There is more
lumber waste than with horizontal sheathing because of the angle
cut, and the application is somewhat more difficult. Figure 16-3
shows the wrong way and the correct way of laying diagonal
sheathing.
251
252 Chapter 16
PLYWOOD
FIBERBOARD
2 ⫻ 8 FT
OR
4 ⫻ 8 FT
Figure 16-1 Method of using plywood on all corners as bracing
when using fiberboard as exterior sheathing.
Plywood Sheathing
Plywood as a wall sheathing is highly recommended because of its
size, weight, and stability, plus the ease and rapidity of installation
(see Figure 16-4). It adds considerably more strength to the frame
structure than the conventional horizontal or diagonal sheathing.
When plywood sheathing is used, corner bracing can also be omitted. Large-size panels effect a major savings in the time required
for application and still provide a tight, draft-free installation that
contributes a high insulation value to the walls. The thickness of
plywood wall sheathing is 1/2 inch for 16-inch stud spacing, and
5/ inch to 3/ inch for 24-inch stud spacing. The panels should be
8
4
installed with the face grain parallel to the studs. However, a little
more stiffness can be obtained by installing them across the studs,
but this requires more cutting and fitting. Nail spacing should not
be more than 6 inches on the center at the edges of the panels, and
not more than 12 inches on center elsewhere. Joints should meet on
the centerline of framing members.
Siding 253
DIAGONAL
HORIZONTAL
Figure 16-2 Two methods of nailing on wood sheathing.
254 Chapter 16
(A) Wrong.
(B) Correct.
Figure 16-3 (A) Wrong way of laying wood sheathing, and
(B) correct way.
Urethane and Fiberglass
With the accent in recent years on saving energy, a number of other
insulations have been developed that have high insulating value. For
example, there is urethane, a 11/4 -inch-thick material that, when
combined with regular insulation, yields a resistance (R) factor of
22 (see Figure 16-5). There is also fiberglass insulation with an R
factor of 4.8. Such insulations are particularly good on masonry
construction, because brick itself has very little insulating value and
requires whatever insulation can be built in.
Sheathing Paper
Sheathing paper should be used on a frame structure when wood
or plywood sheathing is used. It should be water-resistant, but
Siding 255
Figure 16-4 Plywood is a popular sheathing.
(Courtesy American Plywood
Assn.)
not vapor-resistant. These exterior air-infiltration barriers block air
movement, but let water vapor pass. Two common brand names
are Tyvek and Typar. It should be applied horizontally, starting
at the bottom of the wall. Succeeding layers should lap about
4 inches, and lap over strips around openings. Strips about 6
inches wide should be installed behind all exterior trim or exterior
openings.
Wood Siding
One of the materials most characteristic of the exteriors of American
houses is wood siding. The essential properties required for wood
siding are good painting characteristics, easy working qualities, and
freedom from warp. These properties are present to a high degree
in the cedars, Eastern white pine, sugar pine, Western white pine,
cypress, and redwood.
Material used for exterior siding should preferably be of a select grade, and should be free from knots, pitch pockets, and wavy
edges. Vertical-grain wood has better paint-holding and weathering
characteristics than flat-grain wood. The moisture content at the
256 Chapter 16
Green for Sun Side
Rigid Urethane
Laminated Aluminum Foil
on Kraft Paper Interlaced
With Fiber Glass
Backside (Stud Side)
With Factory Built-in
Vent Channels
Mineral Fiber Batting
Studs (2 IN. ⫻ 4 IN.)
11/4 IN. Suprathane
Sheathing Board
(Non-structural)
Gypsum Wallboard
Siding
Corner Bracing
(1 IN. ⫻ 4 IN.)
or Flat Metal
Total "R" (Resistance) = 22
Figure 16-5 Urethane in combination with batt insulation
here produces an R factor of 22.
time of application should be that which it would attain in service.
This would be approximately 12 percent, except in the dry Southwestern states, where the moisture content should average about
9 percent.
Bevel Siding
Plain bevel siding (see Figure 16-6) is made in nominal 4-, 5-, and
6-inch widths with 7/16-inch butts; and 6-, 8-, and 10-inch widths
with 9/16- and 11/16-inch butts. Bevel siding is generally furnished in
random lengths varying from 4 to 20 feet.
Drop siding is generally 3/4 inch thick and is made in a variety of
either patterns with matched or shiplap edges. Figure 16-7 shows
three common patterns of drop siding that are applied horizontally.
V-rustic siding (see Figure 16-7A) may be applied vertically (for
example, at the gable ends of a house). Drop siding (see Figure 167B) is designed to be applied directly to the studs, and it thereby
serves as sheathing and exterior-wall covering. It is widely used in
this manner in farm structures (such as sheds and garages) in all parts
of the country. When used over or in contact with other material
Siding 257
Figure 16-6 Bevel siding.
LA
P
EX
PO
SU
RE
(such as sheathing or sheathing paper), water may work through the
joints and be held between the sheathing and the siding. This sets
up a condition conducive to paint failure and decay. Such problems
can be avoided when the sidewalls are protected by a good roof
overhang.
Square-Edge Siding
Square-edge, or clapboard, siding made of 25/32-inch board is occasionally selected for architectural effects. In this case, wide boards
are generally used. Some of this siding is also beveled on the back at
the top to allow the boards to lie rather close to the sheathing, thus
providing a solid nailing surface.
Vertical Siding
Vertical siding is commonly used on the gable ends of a house, over
entrances, and sometimes for large wall areas. The type used may
be plain-surfaced matched boards, patterned matched boards, or
square-edge boards covered at the joint with a batten strip. Matched
vertical siding should preferably not be more than 8 inches wide and
should have 2 eight-penny nails not more than 4 feet apart. Backer
blocks should be placed between studs to provide a good nailing
base. The bottoms of the boards should be undercut to form a water
drip.
Batten-type siding is often used with wide square-edged boards,
which, because of their width, are subjected to considerable
258 Chapter 16
(A)
(B)
(C)
Figure 16-7 Types of drop siding: (A) V-rustic, (B) drop, (C)
rustic drop.
expansion and contraction. The batten strips used to cover the joints
should be nailed to only one siding board so the adjacent board
can swell and shrink without splitting the boards or the batten
strip.
Plywood Siding
Plywood is often used in gable ends, sometimes around windows
and porches, and occasionally as an overall exterior wall covering.
The sheets are made either plain or with irregularly cut striations. It
can be applied horizontally or vertically. The joints can be molded
Siding 259
Table 16-1 Suggested Thickness of Plywood Siding
Minimum Thickness
Maximum Stud Space
3/
8
1/
2
5/
8
16 inches on center
20 inches on center
24 inches on center
inch
inch
inch
batten, V-grooves, or flush. Sometimes it is installed as lap siding.
Plywood siding should be of exterior grade. For unsheathed walls,
the thickness shown in Table 16-1 is suggested.
Preservative Treatment
Houses are often built with little or no overhang of the roof, particularly on the gable ends. This permits rainwater to run down freely
over the face of the siding. Under such conditions water may work
up under the laps in bevel siding or through joints in drop siding
by capillary action, providing a source of moisture that may cause
paint blisters or peeling.
A generous application of a water-repellent preservative to the
back of the siding will be quite effective in reducing capillary action
with bevel siding. In drop siding, the treatment would be applied
to the matching edges. Dipping the siding in the water repellent
would be still more effective. The water repellent should be applied
to all end cuts, at butt points, and where the siding meets door and
window trim.
Wood Shingles and Shakes
Cedar shingles and shakes come in a variety of grades. They may
be applied in several ways. You may get them in random widths
18 to 24 inches long, or in a uniform 18 inches. The shingles may
be installed on regular sheathing or on an under course of shingles
(which produces a shadowed effect). Cedar stands up to the weather
well and does not have to be painted.
Installation of Siding
The spacing for siding should be carefully laid out before the first
board is applied. The bottom of the board that passes over the top
of the first-floor windows should coincide with the top of the window cap (see Figure 16-8). To determine the maximum board spacing or exposure, deduct the minimum lap from the overall width
of the siding. The number of board spaces between the top of the
260 Chapter 16
SIDING FLUSH
WITH TOP OF DRIP
FLASHING SET FIRST
METAL FLASHING
OVER DRIP CAP
BUILDING PAPER
AROUND WINDOW
OPENING UNDER
FRAME
SCRIBE TIGHT
AGAINST WINDOW
CASING
FOUNDATION
WALL
JOIST
BUILDING PAPER
UNDER SIDING
4 IN. LAP
Figure 16-8 Installation of bevel siding.
window and the bottom of the first course at the foundation wall
should be such that the maximum exposure will not be exceeded.
This may mean that the boards will have less than the maximum
exposure.
Siding starts with the bottom course of boards at the foundation
(see Figure 16-9). Sometimes the siding is started on a water table,
which is a projecting member at the top of the foundation to throw
off water (see Figure 16-10). Each succeeding course overlaps the
upper edge of the lower course. The minimum head lap is 1 inch
for 4- and 6-inch widths, and 11/4 inch for widths over 6 inches.
The joints between boards in adjacent courses should be staggered
as much as possible. Butt joints should always be made on a stud,
or where boards butt against window and door casings and corner
Siding 261
STUD
HEADER
SIDING
PLATE
SUBFLOOR
SHEATHING
BLOCKING
EXTEND SIDING
BELOW BLOCKING
JOIST
PLATE
FOUNDATION
WALL
GRADE
Figure 16-9 Installation of the first or bottom course.
WATER TABLE
Figure 16-10 A water table, which is sometimes used.
262 Chapter 16
boards. The siding should be carefully fitted and be in close contact with the member or adjacent pieces. Some carpenters fit the
boards so tight that they have to spring the boards in place, which
assures a tight joint. Loose-fitting joints allow water to get behind
the siding, thereby causing paint deterioration around the joints
and setting up conditions conducive to decay at the ends of the
siding.
Types of Nails
Nails cost very little compared to the cost of siding and labor, but
the use of good nails is important. It is poor economy to buy siding
that will last for years and then use nails that will rust badly within a
few years. Rust-resistant nails will hold the siding permanently and
will not disfigure light-colored paint surfaces.
There are two types of nails commonly used with siding, one
having a small head and the other a slightly larger head. The smallhead casing nail is set (driven with a nail set) about 1/16 inch below the
surface of the siding. The hole is filled with putty after the prime coat
of paint is applied. The large-head nail is driven flush with the face
of the siding, with the head being later covered with paint. Ordinary
steel wire nails tend to rust in a short time and cause a disfiguring
stain on the face of the siding. In some cases, the small-head nail
will show rust spots through the putty and paint. Noncorrosivetype nails (galvanized, aluminum, and stainless steel) that will not
cause rust stains are readily available.
Bevel siding should be face-nailed to each stud with noncorrosive
nails, the size depending upon the thickness of the siding and the
type of sheathing used. The nails are generally placed about 1/2 inch
above the butt edge, in which case they pass through the upper edge
of the lower course of siding. Another method recommended for
bevel siding by most associations representing siding manufacturers
is to drive the nails through the siding just above the lap so that the
nail misses the thin edge of the piece of siding underneath. The latter
method permits expansion and contraction of the siding board with
seasonal changes in moisture content.
Corner Treatment
The method of finishing the wood siding at the exterior corners
is influenced somewhat by the overall house design. Corner boards
are appropriate to some designs, and mitered joints to others. Wood
siding is commonly joined at the exterior corners by corner boards,
mitered corners, or metal corners.
Siding 263
SIDING
Figure 16-11 Corner
treatment for bevel siding using
the corner board.
CORNER
BOARDS
Corner Boards
Corner boards (see Figure 16-11) are used with bevel or drop siding
and are generally made of nominal 1- or 11/4-inch material, depending upon the thickness of the siding. They may be either plain or
molded, depending on the architectural treatment of the house. The
corner boards may be applied vertically against the sheathing, with
the siding fitting tightly against the narrow edge of the corner board.
The joints between the siding and the corner boards and trim should
be caulked or treated with a water repellent. Corner boards and trim
around windows and doors are sometimes applied over the siding,
a method that minimizes the entrance of water into the ends of the
siding.
Mitered Corners
Mitered corners (see Figure 16-12)
must fit tightly and smoothly for the
full depth of the miter. To maintain a
tight fit at the miter, it is important
that the siding is properly seasoned before delivery, and is stored at the site
to be protected from rain. The ends Figure 16-12 The
should be set in oil-based paint when mitered corner
the siding is applied, and the exposed treatment.
faces should be primed immediately after it is applied. At interior
corners, shown in Figure 16-13, the siding is butted against a corner
strip of nominal 1- or 11/4-inch material, depending upon the thickness of the siding.
Metal Corners
Metal corners (see Figure 16-14) are made of 8-gage metals (such
as aluminum and galvanized iron). They are used with bevel siding
as a substitute for mitered corners, and can be purchased at most
lumberyards. The application of metal corners takes less skill than
is required to make good mitered corners, or to fit the siding to
a corner board. Metal corners should always be set in white lead
paint.
264 Chapter 16
BUTT JOINTS TO BE MADE
OVER CENTER OF STUD
6 IN. MIN
.
Figure 16-13 The construction of an interior corner using
bevel siding.
Metal Siding
The metal most popular of those used
in siding is aluminum. It is installed
over most types of sheathing with an
aluminum building paper (for insulation) nailed on between the sheathing
and siding or insulation built onto the Figure 16-14 Corner
siding. Its most attractive characteris- treatment for bevel
tic is the long-lasting finish. The cost siding using the corner
of painting and maintenance has made metal caps.
this type of siding doubly attractive.
Aluminum siding can be installed over old siding that has cracked
and weathered, or where paint will not hold up.
Vinyl Siding
Also popular is vinyl siding (see Figure 16-15). This comes in a wide
variety of colors, textures, and styles. As with aluminum siding, the
big advantage of vinyl siding is that it does not need to be painted and
will not corrode, dent, or pit. It is relatively susceptible to cracking
if hit when it is very cold.
Siding 265
Figure 16-15 Solid vinyl siding comes in various colors and
textures. It never needs to be painted.
Summary
Sheathing is nailed directly to the framework of the building. The
purpose of sheathing is to strengthen the structure, to provide a
nailing base for siding, and to act as insulation. Types of sheathing
include fiberboard, wood, plywood, urethane, and fiberglass.
Fiberboard is generally furnished in 2-foot × 8-foot or 4-foot ×
8-foot sheets and is usually coated with an asphalt material to make
it waterproof. When fiberboard sheathing is used, most builders will
use plywood at all corners to strengthen the walls. Fiberboard is
normally 1/2- or 25/32-inch thick and generally tongue-and-grooved.
Wood sheathing is generally any size from 1 inch × 6 inches to
1 inch × 12 inches in width. The material may be installed horizontally or diagonally with all joints made over a stud. Diagonal
sheathing should be applied at a 45o angle. This adds greatly to the
rigidity of the walls and eliminates the need for corner bracing. More
lumber waste is realized than when applying horizontal sheathing,
but an excellent tie to the sill plate is accomplished when installed
diagonally.
One of the most popular exterior-wall finishes of American
houses is wood siding. Various types or styles include bevel, drop,
square-edge, and vertical siding. A number of methods are used as
266 Chapter 16
a corner treatment when using wood bevel siding. Some corners are
designed to use a vertical corner board, which is generally 1- or
11/4-inch material. Mitered corners are sometimes used, or the same
effect can be obtained by using metal corners.
Of the metal sidings, aluminum is the most popular.
Review Questions
1. What is fiberboard and how is it used as sheathing?
2. What are some advantages in using wood sheathing placed
3.
4.
5.
6.
7.
8.
9.
10.
diagonally?
Name the various styles of wood siding.
How are corners on wood siding treated?
What is a water table?
What is the advantage of having fiberboard with tongue-andgrooved edges?
At what angle is diagonal sheathing applied?
What is the advantage of applying sheathing diagonally?
Sheathing paper should be used on a frame structure when
sheathing is used.
wood or
True or false: vertical siding is commonly used on the gable
ends of a house.
Appendix A
Professional and Trade
Associations
Table A-1 shows some professional and trade associations in the
fields of doors and windows.
Table A-1 Professional and Trade Associations
Organization
Address
Web Site
American Architectural
Manufacturers
Association
1827 Walden Office
Square, Suite 104,
Schaumburg, lL
60175-4628
801 North Plaza
Drive, Schaumburg, IL
60175-4977
555 Lexington
Avenue, 17th Floor,
New York, NY 10017
14150 Newbrook
Drive, Suite 200,
Chantilly, VA
20151-2225
2945 SW Wanamaker
Drive, Suite A, Topeka,
KS 66614-5521
1500 Spring Street,
Suite 500, Silver
Spring, MD 20910
8200 Greensboro
Drive, McLean, VA
22102
1400 East Touhy
Avenue, Suite 470, Des
Plaines, IL 60018
401 North Michigan
Avenue, Chicago, IL
60611
50200 Detroit Road,
Cleveland, OH
44145-1967
1500 Sumner Avenue,
Cleveland, OH
44115-2851
www.aamanet.org
American Hardware
Manufacturers
Association
Builders Hardware
Association
Door and Hardware
Institute
Glass Association of
North America
National Fenestration
Rating Council
National Glass
Association
National Wood Window
and Door Association
Sealed Insulating Glass
Manufacturing
Association
Steel Door Institute
Steel Window Institute
www.ahma.org
www.builders
hardware.com
www.dhi.org
www.glasswebsite.
com
www.nfrc.org
www.glass.org
www.nwwda.org
www.sigmaonline.
org/sigma/
www.steeldoor.org
www.steelwindows.
com
267
Index
A
adjustable metal stake spreader,
12
adjustment screws, 69, 70
aluminum
for extension ladders, 43, 45
as siding, 264
as termite barrier, 115
aluminum building paper, 64
aluminum ladder jacks,
51–52, 53
aluminum roofing, 182
anchor bolts, 87
anchoring
of footings, 37
of ladders, 55
of scaffolding, 67
of sills, 116, 117
arches, stripping concrete forms
for, 36, 38
ashlars line, 2, 7
asphalt
on built-up roof, 185–186
grades of, 185
asphalt-impregnated felts,
179–180
asphalt-saturated rag felt,
197
asphalt shingles
alignment of, 193–194
application of, 192–197,
198–199
bending, 196
description of, 180
and dormers, 197, 199
drip edge for, 193
finishing hips and ridges with,
196–197
flashing valleys for, 195–196
nailing, 193, 194–195,
196–197
packaging of, 192, 195, 196
qualities of, 180
and slope of roof, 182, 192, 197,
198
starter course for, 194
underlayment for, 192–193
ventilation of roofs with,
197
wrappings for, 195, 196
awning windows, 243, 245
B
backer blocks, 257
backing
defined, 159
of hip rafters, 159–161
of octagon rafters, 167
balloon-frame construction, 99,
100
base course, 11
basement foundations, 21, 24
basement girders, 111–113
basements, concrete floors in,
93–94
basement walls
face line of, 1, 6–7
thickness of, 87
batten strips, 258
batten-type siding, 257–258
batter boards
erecting, 4
and layout lines, 6
for slab-on-grade foundations,
16
batt insulation, 256
bay windows, 243, 245–246
beams, adjusting size of, 27
bevel siding
attaching to studs, 256, 258
corner boards for, 263
corner treatment of, 265–266
drop siding, 256, 258
installation of, 260–261
metal corners for, 263, 264
nailing, 262
resistance to water, 256–257,
259
sizes of, 256
V-rustic siding, 256, 258
269
270 Index
blind stops, 244
bolts
for anchoring sills to
foundations, 116
for attaching plates to masonry
walls, 87
for industrial machinery, 39–40
in ladders, 55
bottom cuts, 152–153
bow windows, 243, 245
box cornices, 219, 223, 225
box rake, 223–224
box returns, 222
box sills
attaching to foundation, 115
in frames, 102
sill plates of, 115
uses of, 115
braced framing sills, 116
brace joints, 101
braces, 106
bracing
of concrete framework,
26–27
importance of, 137
lateral, 27
thickness of, 26
types of, 126, 127
versus wall ties, 26
brackets, 71
bridging
in balloon-frame construction,
100
cutting, 118–119
diagonal, 107
diagram of, 120
horizontal, 107
metal, 118
methods of, 107
nailing, 118
of partitions parallel to floor
joists, 131
in platform frame construction,
102
preventing spreading of, 119
purpose for, 118
spacing of rows of, 118
building codes, for concrete block
walls, 96
building lines
diagram of, 6
grade lines, 5
laying out, 6
laying out with method of
diagonals, 3
laying out with surveyor’s
instrument, 2–3
types of, 1–2, 6–7
buildings
ashlars line for, 7
clearing site for, 9
and contour of ground, 5
cost of concrete frames for, 27
face line for, 6–7
and groundwater, 6
laying out foundations for,
4–5
laying out site for, 6
line of excavation for, 6
selecting site for, 1
staking out site for, 1–5
built-up corner posts, 125
built-up roofs
application of, 185–186
asphalt on, 185–186
gravel stop of, 185, 186
makeup of, 184–185
perforated felt of, 185
sheathing paper for, 184–185
built-up sills
construction of, 114
and corner joints, 109
importance of, 114
joints for, 116
built-up wood girders
in balloon-frame construction,
100
construction of, 111, 112
sizes of, 114
squaring off ends of, 111
supported by walls, 103
bull-nose blocks, 74
butt joints, 260, 262
butt markers, 234
Index 271
C
cabinetmakers, problems
encountered by, xvii
calculations
for rafter lengths, 146–150,
160–161, 171
for rise in inches, 147
for total rise, 147, 150
for total run, 150
for total run of hip rafters,
155
cant strips, 197
carpenters
cutting rafter tails, 152
economical concerns for, 27
erecting walls by self, 137
problems encountered by, xvii
professional and trade
associations for, 267
carpentry
basic construction material in,
107
equipment for, 43
professional and trade
associations for, 267
casement-type sash, 247
casement windows, 243, 245
casing nails, 262
casings
for doors, 232–234
materials for, 232
sizes of, 232
tools for, 232
for windows, 244
casters
adjustment screws for, 69
brakes for, 60, 70
diagram of, 68
diameters of, 60
and horizontal braces, 62
with plain stems, 70
on uneven ground, 68
cast-in-place concrete floors,
93–94, 95–96
CDX plywood, 109
cedar shingles. See wood shingles
ceiling joists, 131
cement blocks. See concrete blocks
chalk-line method, 189
chimneys
floor openings for, 119–121
requirements for frames around,
173, 177
clapboard siding, 257
clean-out hold, 31, 32
closed cornices, 219–220, 225
closed rake, 223, 224
coal-tar pitch roofs, 183
column-form clamps, 33
columns
adjusting size of, 27
girders supported by, 103
making forms for, 31–32, 33
comer posts, 125
common rafters
calculating length of, 146–150
cuts in, 151–153
example of, 144
and hip rafters, 154
and octagon rafters, 165, 167
tails of, 152
concave Mansard roofs, 141, 143
concrete
air pockets in, 13
for crawl space foundations, 20
curing, 15
darby for, 13, 14
delivery versus mixing of, 20
floating, 13
form boards for (see form
boards)
forms for (see concrete forms;
wooden forms)
and freeze line, 25–26
below ground level, 25
jitterbugging, 13
leveling, 19
mixing, 20, 41
placement of, 12
pouring in forms, 19
pouring in masonry walls, 85–86
practicality of, 31–34
producing round on, 13, 14
rebar for, 19
272 Index
concrete (continued)
removal of forms from, 34,
36–38
rough finish of, 34
screeding, 13
for slab-on-grade foundations,
12–15
smooth finish of, 34
stopping at horizontal groove,
34
stresses on, 30–31
texture of, 34
and time constraints, 31
troweling, 13, 15
weight of, 25
working, 12–13
concrete blocks
aggregates, 74
applying mortar to, 78
basic block-laying for, 77–79,
80, 81
building masonry walls with,
85–96
building methods with, 77–85
bull-nose, 74
compressive strength of, 75
corner, 74
face thickness of, 75
importance of, 73, 96
jamb block for, 96–97
laying at corners, 79–80, 81
laying between corners, 80–85
laying for door and window
frames, 81–82, 83, 84
makeup of, 73
mortar for, 76–77
placing, 78, 79
poured concrete, 74
pouring concrete in, 85–86
reinforcement of, 96
setting, 78–79, 80
shapes of, 74, 75, 76, 96
sizes of, 74, 75, 76, 96
solid forms of, 74
standard units of, 74–76
supporting walls of, 82–83, 84,
96
thickness of, 96
tooling mortar joints on, 79, 81
concrete floors
cast-in-place, 93–94, 95–96
on masonry walls, 93–96
precast joists, 93–96
types of, 97
wood floors over, 96
concrete forms
bracing, 25, 26
building, 28, 29, 30
cardboard box for, 38
cleaning, 37
cost of, 25, 27
design of, 25, 27, 37
economical use of, 27
encased in concrete, 37
fastening, 28, 29, 30
form ties for, 28
below freeze line, 25–26
lumber for (see wooden forms)
and lumber lengths, 27
materials for, 25, 26, 41
moldings in, 32, 33
nails for, 28
necessity of, 25
oiling, 37, 41
planning for, 25
prefabricated, 39, 40, 41
recessed grooves in, 32–33
removal of, 26, 34, 36–38
restrictions for, 35
reuse of, 25, 34, 37
size of ties for, 34
spacing of ties for, 34
special types of, 32, 38–40
spreaders for, 34, 35
steel, 25, 26
strength of, 25–26, 41
stripping, 34, 36–38
swelling in, 31–32
and texture of concrete, 34
tying down, 25
wedges for, 28, 30
concrete masonry, 73
concrete slabs, 95–96. See also
slab-on-grade foundations
Index 273
condensation, on skylights, 207
connecting scab, 112
contemporary fireplaces
covering floor around, 178
example of, 177
function of, 173–174
protection from embers of,
174
corner blocks, 74
corner boards, 262–263
corner posts
built-up, 125
preparing, 126
cornice returns
box, 222
closed, 222
defined, 221
design of, 221–223
wide, 223
cornices
box returns for, 222
box-type, 219, 225
closed-type, 219–220, 225
defined, 219, 224
for gable-end finish, 223–224
open-type, 220, 221
for rake finish, 223–224
returns in, 221–223
styles of, 224
types of, 219
wide box-type, 220, 221, 225
coupling pins, 56
crawl space, using SpaceJoist TE
for, 135
crawl space foundations
concrete for, 20
constructing, 15, 20
footings for, 15, 20
form boards for, 20
height of, 20
cripple-jack rafters, 144, 146,
162
cross braces
connecting to end frames, 57
diagram of, 57, 62, 68
double-hole, 59
function of, 56
and planks, 59
between putlogs or trusses, 71
for rolling scaffold towers, 71
safety rules for, 67
securing to end frames, 58
single-hole, 59
sizes of, 59
straddle, 59, 62
types of, 59
cross bridging, 118
crown molding, 222
culverts, stripping concrete forms
for, 36, 38
curing, 15
curtain walls, 96
cut-in bracing, 126
cutting
of jack rafters, 163–164
of octagon rafters, 167, 168
of rafters, 151–159
D
dampers, 173, 174
damp-proofing, 21
darby, 13, 14
dead loads, 103
design wood floorings, 96
diagonal bracing, 102
diagonal bridging, 107
diagonal sheathing
applying, 251, 254
benefits of, 251, 265
diagram of, 253
eliminating corner bracing with,
99, 100, 251, 265
lumber waste from, 251, 265
do-it-yourselfers
problems encountered by, xvii
roofing for, 180–181
skylight kits for, 213, 214
door frames
exterior, 230
hanging doors in, 234–235,
236
parts of, 229
positioning hinges on, 234
preparing openings for, 230
274 Index
doorjambs
casings and stops for, 230–231
checking, 232
construction of, 231–232,
233
cutting head jamb of, 232
dadoes of, 232
defined, 230
marking dimension of butts on,
234
nailing, 232, 233
nailing trim to, 232
openings for, 232
width of, 231
doors
casing openings for, 232–234
construction of doorjambs for,
230–232, 233
construction of frame for,
229–230
construction of trim for,
232–234
flush, 227, 229
for garages, 236–241
hanging, 234–235, 236
hollow-core, 241–242
installing locks in, 234
laminated, 229
lock stile of, 234
louver, 229
manufactured, 227–229
marking dimensions of butts for,
234
in masonry walls, 81–82,
83, 84
mortise joints in, 228
mortising hinges for, 234,
236
openings for, 232
opening sizes for, 129–130
paneled, 227, 228
positioning hinges for, 234
preparing openings for, 230
professional and trade
associations for, 267
sash, 227, 228
sizes of, 227
sliding, 235–236, 238
solid-core, 241
swinging, 235, 237
types of, 227, 241
door trim
casing of, 232–234
nailing to jambs, 232, 233
dormers
and asphalt shingling, 197,
199
defined, 169
flat-roof, 169–170
hip-type, 170, 171
purpose of, 169
types of, 169–171
double-headed nails, 28, 29
double-hole braces, 59, 62
double-hung windows, 243
advantages and disadvantages
of, 245
diagram of, 244
glass panes in, 248–249
parts of, 250
sash in, 244
screens for, 245
ventilation from, 245
dowels, 46
downspouts
connections of, 200
fittings for, 199
guards for, 200
materials for, 199–200
sections of, 199
sizes of, 200
draft stopping, 100
drain tiles, 21
drip edges, 193
dropped girth, 101
drop siding
corner boards for, 263
diagram of, 258
patterns of, 256, 258
preservative treatment of,
259
thickness of, 256
ducts, installing in masonry walls,
88, 90
Index 275
E
edgers, 13, 14
electrical outlets, in masonry
walls, 88, 90
end frames
connecting to cross braces, 57
for sectional scaffolding, 56, 60
selecting correct number of,
64–67
sizes of, 56, 60
toggle pins for, 56
equations, method of diagonals,
3–4
excavation line, 6
extension frames, 56
extension ladders
extension above roofline, 55
metal, 43, 45
placing, 55
push-up, 43, 44
sizes of, 43, 45
wooden, 44
extension planks, 53, 54
exterior walls. See masonry walls;
walls
F
face-shell bedding, 78–79
factory skylights, 204
fascia
defined, 159
and rake boards, 224
fiberboard sheathing
coating on, 251
and frieze boards, 223
nailing, 251
sizes of, 251, 265
strengthening, 251, 252
fiberglass insulation, 254
fiberglass ladders
function of, 45
New York extension trestles, 48
fiberglass strands, 12
fiberglass tape, 2
fireplaces
contemporary, 173, 177, 178
dampers in, 173
framing, 173, 174, 175–176, 177
freestanding, 178
prefabricated, 173, 175–176
requirements for frames around,
173, 177
thickness of walls of, 173
fire resistance
of roofing materials, 183
of skylights, 204, 205
fixed window sash, 246
flashings
around chimneys, 201
for masonry walls, 91–92
materials for, 195–196, 201
purpose of, 91
for skylights, 213, 215
for slate roofs, 197, 199
on valley roofs, 195–196
flat-roof dormer, 169–170
floating, 13
floor framing
bridging, 118–119, 120
around chimneys, 174
for concrete floors, 93–96
connecting joists to sills and
girders, 117–118
cutting joists for, 117, 118
around fireplace, 174
headers and trimmers in, 104,
119–121
increasing rigidness of, 118–119
openings in, 104
subflooring, 121–122 (see also
subflooring)
floor girders, 169
flooring
hardwood, 96
parquet, 96
prefinished, 122
See also subflooring
floor joists
and braced framing sills, 116
bridging, 118–119, 120
connecting to sills and girders,
117–118
construction of partition
between, 130
276 Index
floor joists (continued)
cutting for frames, 117, 118
function of, 109
and girders, 109, 112, 113
headers and trimmers in,
119–121
on masonry walls, 92–93
notching, 117
placing, 117–118
post-and-beam frame
construction, 101
preventing spring in, 118
preventing warping in,
122
solid bridging between,
118–119, 120
spacing of, 92–93
tail beams, 121
floor-plate hinges, 235, 237
floors
concrete, 93–96, 97
framing (see floor framing)
installing in masonry walls,
92–96
flush doors
hanging, 234–235, 236
hollow-core, 227, 229
materials for, 227
solid-core, 227, 229
types of, 227
footings
anchoring, 37
for crawl space foundations 15,
20
depth of, 11
forming, 20
and frost line, 11
projection past foundation wall,
15, 20
reinforcing, 12
thickness of, 20
trenches for, 17
width of, 11
form boards
for crawl space foundations, 20
economical considerations with,
27
kickers for, 11
pouring concrete in, 19
for slab-on-grade foundations,
11, 16, 18
specially ripped, 27
See also concrete forms; wooden
forms
form ties, 28
foundations
anchoring sills to, 116, 117
basement, 21, 24
cost of concrete frames for, 27
crawl space, 15, 20
defined, 9
forms of, 9, 10, 23
for industrial machinery, 38–40
laying in cold weather, 22
layout of, 1, 4–5
for pedestals, 37, 38
for piers, 38–40
pile, 9, 10, 22
requirements for, 116
slab-on-grade, 9–15
spread, 9, 10
types of, 9, 10, 23
wood, 9, 10, 22–23
foundation walls
for basement foundations, 21
parging, 21
preventing seepage of moisture
through, 21
projection of footings past, 15,
20
securing to footing, 20
sills on, 114
frames
balloon-frame construction of,
99, 100
braces for, 106
bridging of, 107
around chimneys and fireplaces,
173–178
construction methods for,
99–102
erecting, 126–127
girders in, 102–103, 109
headers in, 104, 128
Index 277
joists in, 103, 104, 109
ledger plates in, 106
lumber for, 107–109
nailing sheathing to, 265
around openings, 104, 127–130
openings of floors of, 104
partitions in (see partitions)
platform frame construction of,
99, 102
plywood sheathing for, 252, 254
post-and-beam construction of,
99, 101
rafters in, 107
of roofs, 141
sills in, 100, 102, 109
sizes of openings for windows
and doors in, 129–130
studs in, 106
subflooring in, 103–104, 105,
109
walls in (see walls)
framing
balloon-frame, 99, 100
braces for, 106
bridging methods for, 107
of floor openings, 104
girders in, 102–103, 109
headers for, 104
joists for, 103, 104, 109
ledger plates for, 106
lumber for, 107–109
methods of, 99–102
of partitions, 104–105
platform, 99, 102
post-and-beam, 99, 101
rafters for, 107
sills for, 100, 102, 109
studs for, 106
subflooring for, 103–104, 105,
109
of walls, 104–105
framing lumber
for girders, 111, 114
for sheathing, 109
for siding, 109
sizes, 108–109
softwoods, 108
for trusses, 169
types of, 108–109
for walls, 109
framing squares
for cuts in octagon rafters, 167,
168
for cutting rafters, 151–153
finding proper length of rafters
with, 147
importance of, 139
for jack rafters, 163, 164
for method of tangents, 164–165
multiposition method with, 147,
148
reading hundredths scale on, 150
reading straightedge in
combination with, 149, 150
scaling method with, 147, 148
freestanding fireplaces, 178
free-standing scaffold towers, 70
freeze line, 25–26
French roofs, 141, 143
friction piles, 22
frieze boards
and cornices, 219–220
and fiberboard sheathing, 223
function of, 225
juncture with soffits, 220
for siding ends, 222
and wood sheathing, 223–224
furring, 173
G
gable roofs
cornice return on, 221–223
description of, 139, 140
finishes for, 223–224
laying wood shingles on, 190
gage-and-hatchet method, 189
gambrel roofs, 139, 140
garage door openers, 240–241
garage doors
automatic openers for, 240–241
design of, 240
furnishing, 239–240
for house-attached garages, 240
image of, 238
278 Index
garage doors (continued)
importance of, 236–237
materials for, 239
ordering, 237, 239–240
safety factor in, 240–241
standard size of, 237
types of, 239
windows in, 238, 240
garden walls, 85
girders
basement, 111–113
built-up wood, 100, 103, 111,
112
connecting joists to, 117–118
construction of, 111, 112
defined, 111, 122
in frames, 102–103
function of, 102, 109, 122
with ledger strip, 106
on masonry walls, 92–93
materials for, 109, 111, 112,
113, 122
placing, 117
in platform frame construction,
102
shoring, 113
sizes of, 103, 114
squaring off ends of, 111
supports for, 103, 112–113
thickness of, 122
girth joints, 101
glass-fiber shingles
description of, 180
pictures of, 181
glaziers’ point, 248, 249
glazing sash, 248–249
gliding windows, 243, 245
grade levels, 5
grade lines, 5–6
granulated insulation, 91
gravel stops, 185, 186
groundwater
checking levels of, 1
problems with, 6
guardrail posts, 58–59,
61, 68
gutters
connections of, 200
deterioration of, 201
fittings for, 199
guards for, 200
materials for, 199–200
seamless, 200
sections of, 199
slope of, 200–201
and snow banking, 200
standard lengths of, 200
H
handsaws, 133
hardwood flooring, 96
hatchets, 189–190
headers
angle of, 121
classes of, 128
defined, 119
diagram of, 120
for floor openings, 119–121
framing, 104
function of, 104
load-bearing, 128
nonbearing, 128
for openings in partitions or
walls, 131
in platform frame construction,
102
and siding installations, 261
sizes of, 128
of T-sills, 115
heating ducts, installing in
masonry walls, 88, 90
hinged skylights, 203
hinged windows, 245
hip-and-valley rafters, 155
hip-and-valley roofs
description of, 139, 141
figure of, 142
jack rafters in, 161–162
hip-jack rafters, 144, 145, 161,
162
hip rafters
backing of, 159–161
in balloon-frame construction,
100
Index 279
and common rafters, 154
cuts in, 153–159
description of, 144, 153–154
example of, 144, 145
flush cut of, 158
full-tail, 159
length of, 155, 156
method of tangents for cuts in,
164–165, 166
in platform frame construction,
102
side cuts of, 159, 160
table length of, 157
total run of, 155–157
versus valley rafters, 157
hip roofs
and asphalt shingles,
196–197
cornices for, 220
description of, 139, 141
laying wood shingles on, 190,
191
hip-type dormers, 170, 171
hoist standard, 59, 63
hollow-core doors
base of, 227
description of, 241–242
edging strips for, 227, 229
face of, 229
installing doorknobs and locks
in, 229
horizontal braces
function of, 69
for rolling scaffold towers, 60,
62, 68
spacing of, 62, 69, 71
horizontal bridging, 107
household stepladders, 46, 47
house pads, 51, 52
houses
foundations of (see foundations)
frames of (see frames)
preservative treatment of, 259
selecting site for, 1
skylights in, 204–207
strength of, 99
trusses for, 167–169
I
industrial machinery
bolts for, 39–40
laying foundations for, 38–40
insulated glass, 246
insulation
with aluminum building paper,
264
batt, 256
fiberglass, 254
granulated, 91
of masonry walls, 90–91
of plywood sheathing, 252
rigid foam, 91
of roofs, 183
in SpaceJoist TE, 133
Styrofoam, 90–91
urethane, 254, 256
interior partitions
bottom plate of, 131
constructing between ceiling
joists, 131
costs reduction for, 132–133,
137
versus outside partitions, 130
parallel to joists, 130–131
at right angles to joists, 131
SpaceJoist TE for, 131–137
support of, 130
top plate of, 131
weight of, 130
J
jack rafters
cripple jacks, 162
cuts in, 163–164
defined, 144
framing, 162–163
framing-table method for, 163
hip jacks, 161, 162
on hip-roof dormer, 171
longest-jack method for,
162–163
method of tangents for cuts in,
164–165, 166
shortest-jack method for, 162
side cut of, 163–164
280 Index
jack rafters (continued)
types of, 161–162
valley jacks, 162
jamb blocks, 96–97
jitterbugging, 13
joints
for built-up sills, 116
for siding, 260, 262
between siding and corner
boards, 263
joist hangers, 120
joists
in balloon-frame construction,
99, 100
and chimneys, 173
concrete, 95
cutting, 133
dead load of, 103
doubling, 95, 96
in frames, 103, 104
function of, 103, 109
girders for, 109
installing in masonry walls,
96–97
live load of, 103
maximum dimensions for, 136
mounted over basement, 134
open-web system of, 132
partitions at right angles to,
131
partitions parallel to, 130–131
in platform frame construction,
102
providing additional strength for,
130
and siding installations, 261
SpaceJoist TE, 131–137
spacing of, 95
supporting with ledger plate,
106
thickness of, 103
for western frame box-sill
construction, 115
K
keyways, 20
kickers, 11
L
ladder hooks, 53, 54
ladder jacks
adjusting, 51
aluminum, 51–52, 53
installing, 51–52
side-rail, 52, 53
ladders
accessories for, 51, 52
accident-proofing, 55
adjusting feet of, 55
aluminum jacks for, 51–52,
53
anchoring, 55
attachments for, 71
balancing, 55
carrying tools on, 55
climbing, 55
correct angle for, 55
distance from house, 49, 55
and electrical lines, 45
extension, 43, 45
extension above roofline, 55
fiberglass, 45
function of, 71
hooks for, 53, 54
magnesium, 45
materials for, 71
metal extension, 43, 45
New York extension, 47–49
pail shelf for, 52
placement of, 49
planks for, 53, 54
pole lash for, 52
preventing sliding of, 51, 52
push-up, 43
raising, 49, 50, 71
ratings for, 55
safety precautions for, 55
on scaffolding, 70
securing, 43, 44
selecting, 55
shoes for, 49–51
side-rail jacks for, 52, 53
single straight, 43, 44
stabilizer for, 52
stepladders, 45–46
Index 281
telescoping extension planks, 53,
54
transporting, 53–55
trestles, 46–47, 48
truck caddy rack for, 53–55
wooden, 55
working length of, 43
ladder shoes
adjusting, 55
function of, 49
placing boards under, 55
rubber, 49–50
steel-spur wheel, 50, 51
stepladder, 50–51
types of, 49–51
universal-safety, 50, 51
Lally columns, 113
laminated doors, 229
lap siding, 259
large-head nails, 262
lateral bracing, 27
lathing, 173
layout
defined, 1, 6
points on, 5–6
leaks, from skylights, 213,
215
lean-to roofs, 139
ledger boards, 99, 100
ledger plates, 106
level lines, 143
levels, for setting sills, 116
light-framed construction
balloon-frame, 99, 100
platform, 99, 102
post-and-beam, 99, 101
line length, 143
line of excavation, 1
lintels
placing in masonry walls, 82–83,
84
reinforcement of, 82
live loads, 103
load-bearing headers, 128
load-bearing walls
bearing strength of, 104–105
description of, 86
joining, 87, 88
mortar for, 77
thickness of, 85
locks, installing in doors, 234
longest-jack method, 162–163
lookout cuts, 152–153
lookouts
for cornices 225
nailing, 220, 225
on rafters, 220
for rake section of roof, 224
for wide box cornices, 220
louver doors, 229, 230
louver shutters, 250
lug sills, 83–84
lumber
for concrete forms, 28
economical use of, 27
for framing, 108–109
kiln-dried, 28
nominal size of, 107–108
for scaffold planks, 70
standard sizes of, 107–108
for stepladders, 46
for wooden forms, 29
for wood siding, 255
M
magnesium ladders, 45
Mansard roofs
concave, 141, 143
description of, 141
figure of, 142–143
manufactured doors
flush doors, 227, 229
hollow-core, 227, 229
louver, 229, 230
mortise joints in, 228
paneled doors, 227, 228
sash doors, 227, 228
sizes of, 227
solid-core, 227, 229
masonry cement, 76–77
masonry walls
in balloon-frame construction,
100
in basement, 87
282 Index
masonry walls (continued)
basic block-laying for, 77–79,
80, 81
building, 85–96
building between corners, 80–85
building codes for, 96
building frames in, 81–82,
83, 84
building methods with, 77–85
cast-in-place, 87
concrete floors on, 93–96
door and window frames in,
81–82, 83, 84
electrical outlets in, 88, 90
flashings for, 91–92
installation of ducts in, 88, 90
installing floors in, 92–96
installing joists in, 96–97
insulation of, 90–91
interior, 87, 88
jamb block for, 96–97
laying blocks at corners of,
79–80, 81
load-bearing (see load-bearing
walls)
mortar for, 76–77
placing lintels in, 82–83, 84
placing sills in, 82–85
plates in, 87, 89
in platform frame construction,
102
pouring concrete in, 85, 86
reinforcement of, 85–87, 96
under severe conditions, 77
sills on, 87, 89, 117
support of, 82–83, 84, 96
thickness of, 85
tooling mortar joints on, 79, 81
troweling, 78
wiring in, 88
wooden floors on, 92–93, 96
metal bridging, 107, 118, 119
metal corners, 262, 263, 264,
266
metal extension ladders
description of, 43
sizes of, 43, 45
metal roofing, 179
under wood shingles, 190–192
metal siding, 264
metal stake spreader, 12
metal tape
for laying out building lines, 2
for method of diagonals, 4
metal windows, 246
method of diagonals
equation for, 3–4
for laying out building lines, 3–5,
6
tools for, 3
method of tangents, 164–165, 166
mill-built doors
casing openings for, 232–234
construction of doorjambs for,
230–232, 233
construction of frame for,
229–230
construction of trim for,
232–234
frame parts, 229–230
installing, 229–234
openings for, 232
preparing openings for, 230
Miller, Mark Richard, xv
Miller, Rex, xv
miter cuts, 158–159
mitered corners, 262, 266
moldings, in concrete forms, 32,
33
mortar
adding water to, 76
applying to blocks, 78
applying to wall corners, 80, 81
in basic block-laying methods,
77–78
color of, 76
function of, 76
for load-bearing walls, 77
for lug sills, 85
for masonry walls, 76–77
mixing, 76–77
qualities of, 76
tooling joints of, 79, 81
troweling, 78–79
Index 283
movable window sash, 246–247
mullions, 245
muntins, 246
open cornices, 220, 221
outside partitions, 130
P
N
nailing blocks, 224
nailing plates, 59
nails
for asphalt-shingled roofs, 193,
194–195, 196–197
for bevel siding, 262
for built-up roofs, 185
casing, 262
for concrete forms, 28, 29
cost of, 262
for door trim, 233
double-headed, 28, 29
for fastening bridges of floor
joists, 118
for fiberboard sheathing, 251
for girders, 111
large-head, 262
for lookouts, 220
noncorrosive-type, 262
rust-resistant, 262
for siding installations, 262
for slate roofing, 197
small-head, 262
for wood shingles, 188, 189
New York extension trestle
fiberglass, 48–49
locking device for, 47–48
middle ladder for, 48
sizes of, 48
nonbearing headers, 128
O
Occupational Safety and Health
Administration (OSHA)
ratings for ladders, 55
on step ladders, 46
octagon rafters
backing of, 167
and common rafters, 167
cuts in, 167, 168
description of, 146, 165
finding length of, 167
pail shelf, 52
paneled doors
component parts of, 227,
228
materials for, 227, 241
mortise joints in, 228
rails and stiles of, 227
styles of, 241
parging, 21
parquet flooring, 96
parting strips, 244
partition caps
in balloon-frame construction,
100
makeup of, 105
in platform frame construction,
102
partitions
arrangement of studs in,
104–105
bearing strength of, 104–105
bottom plate of, 131
building, 87, 88
constructing between ceiling
joists, 131
corner posts in, 105
costs reduction for, 132–133,
137
defined, 105, 130, 137
framing, 104–105
installation of ducts in, 88, 90
interior (see interior partitions)
joining to exterior walls,
87, 88
load-bearing, 105
materials for, 130
nonbearing, 105
parallel to joists, 130–131
requirements for, 125
at right angles to joists, 131
structural elements of, 104
thickness of, 85, 96
top plate of, 131
284 Index
partitions (continued)
T-posts in, 105
types of, 105
weight of, 130
pedestal footings, 37
pedestals, laying foundations for,
37, 38–39
perforated felt, 185
piers
and built-up sills, 116
laying foundations for, 38–40
under severe conditions, 77
pile foundations
classifications of, 22
diagram of, 10
function of, 9, 22
stability of, 9
pitch, 143
pitch roofs
description of, 139, 140
mineral coating for, 183
plank bracing, 126, 127
planks
cleated, 70
and cross braces, 59
fabricated, 70
ladder jacks for, 51–53
ladders on, 70
lumber for, 70
overlap of, 70
placed on trestles, 46, 47, 48
placing between ladders, 51–52,
53
on rolling scaffolds, 71
for scaffolding, 70
securing, 70
Stinson, 47, 48
telescoping extension, 53, 54
plaster, 173
plates, in masonry walls, 87, 89
platform frame construction, 99,
102
platform supports, 60, 63
plugging, 173
plumb lines, 143
plywood
sheathing grade (CDX), 109
for strengthening fiberboard
sheathing, 251, 252
for subflooring, 104
plywood forms. See wooden forms
plywood sheathing
advantages of, 252
nailing, 252
sheathing paper for, 254–255
thickness of, 252
plywood siding, 258–259
point-bearing piles, 22
pole lash, 52
pole straps, 51, 52
Portland cement, 76, 77
post-and-beam construction, 99,
101
power lines, and scaffolding, 70
power trowels, 13, 15
precast joist concrete floors,
93–96
prefabricated fireplaces
dampers in, 173
framing, 173, 174, 175–176,
177
sitting on bricks, 175
sitting on concrete blocks, 176
prefabricated forms, 39, 40, 41
prefinished flooring, 122
professional associations, 267
projection moldings, 32
push-up ladders
securing, 43, 44
sizes of, 43
working length of, 43
putlogs, 71
R
rafters
in balloon-frame construction,
100
calculating length of, 146–150,
160–161, 171
and chimneys, 173
common, 144, 151–153, 154,
156
connection to walls, 107
cornices in, 219
Index 285
cripple-jack, 144, 146
cuts in, 151–159
defined, 141, 171
fastening, 107
function of, 107, 143, 171
hip, 144, 145, 153–161
hip-jack, 144, 145
jack, 144, 161–164
lookouts on, 220
method of tangents for cuts in,
164–165, 166
octagon, 146, 165, 167, 168
parts of, 146
in platform frame construction,
102
in post-and-beam frame
construction, 101
sizes of, 107
sizing of, 143
spacing of, 107
total rise of, 147
total run of, 155–157
types of, 144–146, 171
valley, 144, 157–159
valley-jack, 144, 145
with zero pitch, 164–165, 166
rafter tails
for common rafters, 152
flush, 152
full, 152
separate, 152
rake boards
box-type, 223–224
closed-type, 223, 224
lookouts for, 224
open-end finish of, 224, 225
for siding ends, 222
types of, 223
random-length wales, 27
rebar, 19
reinforcement bars, 86
residential skylights
designs of, 206
and external noise, 206–207
heating from, 204–205
for kitchens, 207
locating, 205–206
rigid foam insulation, 91
rise in inches
calculating, 147
defined, 143
per foot run, 151–152
rolling scaffold towers
adjustment screws for casters of,
69
assembling, 60, 62
casters for, 60, 62, 68–69
components of, 60, 68
horizontal braces for, 62, 71
maximum platform height on, 71
moving, 70–71
for painters, 68
preventing racking of, 62
safety rules for, 70–71
securing materials of, 70
roll roofing
description of, 180, 183
installation of, 184
sheathing of, 183–184
and slope of roof, 182
uses of, 183
and wind, 184
under wood shingles, 190, 192
roof covers. See roofing
roofing
aesthetic effect of, 183
asphalt shingles, 180, 192–197,
198–199
for built-up roofs, 184–186
choosing materials for, 182–183
cost of, 182–183
defined, 179, 201
felts for, 179–180, 185
fire resistance of, 183
glass-fiber shingles, 180–181
heat absorption of, 183
materials for, 179–181
metal, 179
pitch, 183
quantities of, 182
resistance to wind, 182
rolls of (see roll roofing)
slate, 179, 197, 199
and slope of roof, 182
286 Index
roofing (continued)
tile, 179
types of, 201
wood shingles, 179, 186–192
roofing nails
for asphalt-shingled roofs, 193,
194–195, 196–197
for built-up roofs, 185
for slate roofing, 197
for wood shingles, 189
roofs
built-up, 184–186
choosing roofing materials for,
182–183
connection to walls, 107
construction of, 141, 143
costs for covering, 182–183
cut of, 143
dormers for, 169–171
drainage of, 182
frames of, 141, 143, 171
framing around chimneys, 174
French, 141, 143
gable, 139, 140
gambrel, 139, 140
gutters and downspouts for,
199–201
hip, 139, 141
hip-and-valley, 139, 141–142
insulation of, 183
lean-to, 139
level line of, 143
line length of, 143
Mansard, 141, 142
pitch, 139, 140
pitch of, 143
plumb line of, 143
purpose of, 141
rafters for (see rafters)
requisite strength of, 141
rise in inches of, 141
roofing of (see roofing)
run of, 149
sections of, 179, 201
skylights in, 204, 213–216
slope of, 182
span of, 141
total rise of, 141, 150
total run of, 143, 150
trusses for, 167–169
types of, 139–141, 142–143
unit of run for, 143
view of entrance to, 204
rough floor, 121–122
rough sills
diagram of, 244
function of, 128
location of, 127–128
on window frame, 244
rust-resistant nails, 262
S
sash. See window sash
sash doors
component parts of, 227, 228
with glazed sash, 228
hanging, 234–235, 236
materials for, 227, 241
mortise joints in, 228
rails and stiles of, 227
styles of, 241
sash weights, 247
scab board, 113
scaffolding
accessories for, 71
adjusting screws for, 66
anchoring, 67
casters for, 60, 62, 68–69
climbing, 67
components of, 56–62
connecting end frames and cross
braces for, 56, 57
coupling pin for, 56, 59
cross braces of, 56, 57
enclosures of, 67, 70
end frames of, 56, 57
extension frames for, 56
figuring height of, 59, 64–67
free-standing, 70
function of, 56, 71
guardrail post for, 58–59, 61
hoist standard for, 59, 63
horizontal braces for, 62, 69
inspection of, 65
Index 287
ladders on, 70
leveling, 66
maintenance of, 65
planked areas of, 70
platform supports for, 60, 63
and power lines, 70
putlogs on, 71
regulations for, 56
rolling towers for, 60, 62, 68–69,
70–71
safety of, 56
safety rules for, 62, 64–67, 70–71
securing braces to end frames
for, 56, 57–58
selecting number of frames and
braces for, 59, 64–67
sills for, 66
Speed lock for, 56, 58
trusses on, 71
walk-through frames for, 56, 58,
61
and wind, 67, 70
Scaffolding and Shoring Institute
safety rules, 62, 64–67, 70–71
scaling, finding rafter length by,
149
screeding, 13
screw jacks, 38, 68
seamless gutters, 200
sewers, checking availability of, 1
sheathing
in balloon-frame construction,
99, 100
diagonal, 99, 100, 251, 265
drop siding as, 256, 258
fiberboard, 223, 251, 265
and frieze boards, 223–224
lumber for, 109
nailing, 251, 265
in platform frame construction,
102
plywood, 252, 254
purpose of, 265
and siding installations, 261
for subflooring, 105
types of, 251, 265
wood, 223–224, 251, 265
sheathing grade (CDX) plywood,
109
sheathing paper
air-infiltration barriers of, 255
applying, 255
brands of, 255
for built-up roofs, 184–185
important qualities of, 254–255
shed roofs, 139
shingles
asphalt, 180, 192–197, 198–199
glass-fiber, 180–181
and slope of roof, 182
wood, 179, 182, 186–192
shores, 38
shortest-jack method, 162
shutters, 250
side cuts
of hip rafters, 159, 160
of jack rafters, 163–164
method of tangents for,
164–165, 166
of valley rafters, 159, 160
side-pivoted sash skylights, 204,
205
side-rail ladder jacks, 52, 53
siding
bevel, 256–257, 258, 259,
260–261
bottom course of, 260, 261
butt joints of, 260, 262
corner treatment of, 262–264,
265–266
drop, 256
fiberglass insulation, 254
fitting, 262
installation of, 259–264
loose-fitting joints of, 262
lumber for, 109
metal, 264
metal corners for, 263, 264
mitered corners for, 263, 264
nails for, 262
overlapping, 260
packaging of, 109
plywood, 258–259
preservative treatment of, 259
288 Index
siding (continued)
sheathing (see sheathing)
spacing for, 259–260
tight joints of, 262
urethane insulation, 254, 256
vinyl, 264–265
V-rustic, 256, 258
water resistance of, 256–257
and water table, 260, 261
wood, 255–259
sight levels, 116
sill plates, 115, 116
sills
anchorage of, 116, 117
in balloon-frame construction,
100
box, 102, 115
braced framing, 116
and braces, 106
built-up, 109, 114, 116
classes of, 114
decay in, 117
defined, 114, 122
foundations for, 100
in frames, 100, 102
function of, 122
grooves in, 82–83, 85
installation of, 109
lug-type, 83–84
on masonry walls, 87, 89, 117
placement of, 114
placing in masonry walls,
82–85
in platform frame construction,
102
in post-and-beam frame
construction, 101
purpose of, 82
rough, 127–128
for scaffold posts, 66
setting, 116–117
sizes of, 122
slip-type, 83
T-type, 115
for two-story buildings, 116
types of, 115–116, 122
of windows, 244, 245
single-hole braces, 59
single straight ladder
description of, 43
figure of, 44
sizes of, 43
skylights
condensation on, 207
controls for, 203
defined, 203
in factories, 204
fireproof, 204
flashings for, 213, 215
glass, 210
hinged, 203
importance of, 203
inspection of, 210, 213
installation of, 212, 213–216
leaking from, 213, 215
light-shaft installations of, 207,
208
locating, 216
maintenance of, 207–211, 213
placement of, 203–204
planning for installation of, 207,
209–211
plastic, 210
protecting from outdoor
conditions, 210
in residential dwellings,
204–207
roof-window stationary unit,
211
roof-window vent unit,
209–210
side-pivoted, 204, 205
spread of light from, 213, 215
tube-type, 212, 213–216
wire glass for, 204
slab-on-grade foundations
base course of, 11
batter boards for, 16
cables for, 18
clearing site for, 9
concrete for, 12–15, 19
constructing, 9, 11–12, 23
curing concrete for, 15
fill for, 11
Index 289
floating concrete for, 13
footings for, 11, 12
form boards for, 11, 16, 18
jitterbugging concrete for, 13
laying out, 11
producing round for, 13, 14
rebar for, 19
reinforcing footings of, 12
reinforcing slabs of, 12
screeding concrete for, 13
trenches for footings of, 17
types of, 9, 10
vapor barrier for, 11
working concrete for, 12–13
slate roofing, 179
aesthetic effect of, 183
application of, 197, 199
felt for roofs with, 197
manufacture of, 197
nailing, 197
overlapping sheet metal with,
197
varieties of, 197
slat shutters, 250
sleepers, 96
sliding doors, 235–236, 238
slip sills, 83
small-head casing nails, 262
soffits
for arch culvert, 36
and cornices, 219
for inlet ventilators, 219
juncture with frieze board, 220
nailing surface for, 225
sole plates, 104, 105, 106
soles, 102
solid bridging, 118–119, 120
solid-core doors, 227, 229, 241
solid panel shutters, 250
SpaceJoist TE
advantages of, 131–132
applications of, 134–135
crawl-space construction with,
135
cutting, 133
details of, 135
fire endurance of, 133
floor span chart, 136
insulation of, 133
materials of, 132
mounted over basement, 134
qualifications of, 133
reduction in costs with,
132–133, 137
safety of, 133
span, 141
Speed lock, 56, 58
spiking strips
in balloon-frame construction,
100
in platform frame construction,
102
spreaders
adjustable, 12
in concrete forms, 34, 35
removal of, 34
styles of, 34
spread foundations
basement, 10, 21, 24
crawl space, 10, 15, 20
slab-on-grade, 9–15, 23
types of, 10, 23
square-edge siding, 257
stabilizer, 52
stairways, floor openings for,
119–121
staking out
importance of, 1
by method of diagonals, 3–5
with transit instruments, 2–3
types of lines for, 1–2
starter course, 194
steel forms, 25, 26
steel girders, 113
steel jointer, 79
steel-spur wheel shoes, 50, 51
steel squares
for cuts in octagon rafters, 167,
168
for cutting rafters, 151–153
finding proper length of rafters
with, 147
importance of, 139
for jack rafters, 163, 164
290 Index
steel squares (continued)
for method of tangents, 164–165
multiposition method with, 147,
148
reading hundredths scale on, 150
reading straightedge in
combination with, 149, 150
scaling method with, 147, 148
stepladders
dowels of, 46
duty rating of, 46
household, 46, 47
materials for, 45
ratings for, 46
shoes for, 46, 47, 50–51
tie rods for, 45–46
stepladder shoes, 46, 47, 50–51
stiles
for casement windows, 245
description of, 245
extension for, 234
positioning hinges on, 234
Stinson planks, 47, 48
straddle braces, 59, 62
straightedge method, 189
straightedges, for screeding
concrete, 13
straightedge scale, 149, 150
studs
arrangement of, 104–105
backer blocks for, 257
in balloon-frame construction,
99, 100
bearing strength of, 104
bridging of, 107
and chimneys, 173
in cut-in bracing, 126
and diagonal bridging, 107
drop siding on, 256, 258
in frames, 106
and horizontal bridging, 107
on masonry walls, 90
nailing, 106
at opening in walls, 127–128
in partitions, 130
placement of, 106
in plank bracing, 126, 127
in platform frame construction,
99, 102
preparing, 126
random-length, 27
and siding installations, 261
spacing of, 106
ties for, 34
vertical siding on, 257
wood sheathing on, 251
Styrofoam insulation, 90–91
subflooring
benefit of, 103–104
installing, 109, 121–122
materials for, 104, 105
nailing, 103
and siding installations, 261
swinging doors, 235, 237
swivel-style spring hinges, 235,
237
T
tail beams, 121
tape, for laying out building lines,
2
tar-impregnated felts, 179–180
Tecos, 120
telescoping extension planks, 53,
54
termite barriers, 115
ties, for concrete forms, 34
tile roofing, 179
tinted glass, 246
toe board, 68
tooling, 79, 81
top plates, 104–105
total rise
calculating, 147, 150
defined, 141
total run
calculating, 150
defined, 143
of hip rafters, 155–157
T-posts, 105
trade associations, 267
transits
defined, 2
establishing grade lines with, 5
Index 291
figure of, 4
function of, 2
laying out building lines with,
2–3, 6
trenchers, 17
trestles
extensions for, 47
heights of, 46
New York extension, 47–49
sizes of, 46–47
suspending planks between, 46,
47, 48
weight of, 46–47
trimmers
angle of, 121
defined, 119
diagram of, 120
for floor openings, 119–121
framing, 104
function of, 104
troweling
of masonry walls, 78–79
with power trowel, 15
purpose of, 13
truck caddy rack, 53–55
trusses
costs reduction with, 167–168
materials for, 169
for scaffolding, 71
time savings of, 168–169
T-sills, 115
tube-type skylights
conversion to light fixture, 215
diagram of, 215
flashings for, 213, 215
installation of, 212, 213–216
kits for, 213, 214
leaking from, 213, 215
spread of light from, 213, 215
tunnels, stripping concrete forms
for, 36, 38
Typar, 255
Tyvek, 255
for asphalt shingles, 192–193
purposes of, 193
universal-safety ladder shoes, 50,
51
urethane insulation, 254, 256
V
valley-jack rafters
description of, 144, 162
diagram of, 145
valley rafters, 144
applying source for cuts of,
155
cuts in, 157–159
description of, 144
diagram of, 145
flush cut of, 158
full-tail, 159
versus hip rafters, 157
method of tangents for cuts in,
164–165, 166
plumb cut in, 157
side cuts of, 159, 160
side view of, 157
valley roofs
and asphalt shingles, 195–196
flashings for, 195–196
laying wood shingles on, 190,
192
vapor barriers, 11, 23
veneered doors, 229
ventilating ducts, installing in
masonry walls, 88, 90
ventilation
of asphalt-shingled roofs, 197
in crawl space foundations, 20
for double-hung windows,
245
skylights for, 216
vertical siding, 257–258
vinyl siding, 264–265
V-rustic siding, 256, 258
W
U
underlayment
application of, 192–193
wales, 34
walk-in closets, 235–236, 238
walk-through frames, 56, 58, 61
292 Index
walls
arrangement of studs in,
104–105
bearing strength of, 104–105
bracing for, 126, 137
bridging, 107
built-up corner posts in, 125
concrete blocks for (see concrete
blocks; masonry walls)
connection to rafters, 107
erecting frame of, 126–127
framing, 104–105
framing around openings in,
127–130
framing lumber for, 109
girders supported by, 103
headers in, 128–129
interior (see partitions)
layers of, 109
load-bearing (see load-bearing
walls)
load-bearing headers in, 128
masonry (see masonry walls)
nonbearing headers in, 128
size of headers in, 128
sizes of openings for windows
and doors in, 129–130
structural elements of, 104
wall ties, 26
water-cement ratio, 32
water-repellent preservatives, 259
water table, 260, 261
wedges, for concrete forms, 28, 30
western framing, 99, 102
wide box cornices
diagram of, 223
fascia board of, 220
forming members for, 220
lookouts for, 220, 225
parts of, 221
soffits for, 220
types of roofs for, 220
window frames, 243
window lifts, 247
window panes
in double-hung windows,
248–249
glazing, 248–249
installing, 248
securing, 248
windows
apron of, 244
awning, 243, 245
bay, 243, 245
bead stop of, 244
blind stops of, 244
bow, 243, 245
casement, 243, 245
casing of, 244
diagram of, 244
double-glazing of, 246
double-hung, 243, 244–245,
248, 250
frames of, 243
functions of, 243
glazing of, 246
gliding, 243, 245
hinged, 245
installing sash of, 247
insulated glass for, 246
in masonry walls, 81–82,
83, 84
opening sizes for, 129–130
parting strips of, 244
parts of, 243, 250
professional and trade
associations for, 267
protruding from roof (see
dormers)
sash of, 244
shutters for, 250
skylights (see skylights)
stool of, 244
tinted glass for, 246
triple-glazing of, 246
types of, 243, 250
water resistance of, 245
wood versus metal, 246
window sash
in awning windows, 245
casement-type, 245, 247
cord for, 247
in double-hung windows, 244
fitting in frame, 244
Index 293
fixed, 246
function of, 246
glass lights in, 246
glazing, 248–249
in gliding windows, 245
installation of, 247
movable, 246–247
muntins in, 246
types of, 246
weights for, 247
window sills
for casement windows,
245
diagram of, 244
wire glass, 204
wire mesh, 12
wire ties, 28
wiring, in masonry walls, 88
wooden floors
over concrete floors, 96
hardwood, 96
laying, 96
in masonry walls, 92–93, 96
sleepers in, 96
wooden forms
building, 30–31
cleaning, 37
clean-out hold for, 31, 32
hemlock, 29
kiln-dried, 28
lumber for, 28–31
moldings in, 32, 33
oiling, 28, 37
as open-ended boxes, 31, 32
panels for, 31
pine, 29
popularity of, 25
practicality of, 31–34
pressures exerted on, 30–31
preventing water absorption of,
28
recessed grooves in, 32–33
removal of, 34, 36–38
reuse of, 34, 37
size of ties for, 34
spacing of ties for, 34
spreaders for, 34, 35
spruce, 29
stripping, 34, 36–38
swelling in, 31–32
and texture of concrete, 34
thickness of, 29
and time constraints, 31
and water-cement ratio, 32
wooden ladders, 55
wood foundations
diagram of, 23
installation of, 22
makeup of, 22
popularity of, 9
purpose of, 22
wood shakes, 179, 259
wood sheathing
diagonal, 251, 265
and frieze boards, 223–224
installation of, 265
nailing, 251, 253
sheathing paper for, 254–255
sizes of, 251, 265
thickness of, 251
wood shingles
aesthetic effect of, 183
application of, 186–192
chalk-line method for, 189
gage-and-hatchet method for,
189
grades of, 259
hatchets for, 189
installation of, 259
laying on gables, 190
laying on hips, 190, 191
laying on valleys, 190, 192
lumber for, 259
nailing, 188
overlapping, 186–188
packaging of, 186
quality grades of, 186
resistance to wind, 182
sizes of, 186, 259
space between, 188
space covered by, 188
spacing of, 186, 188
straightedge method for, 189
swelling of, 188
294 Index
wood siding
batten-type, 257–258
bevel, 256–257, 258
corner treatment of, 262–264,
265–266
essential properties of, 255
lumber for, 255
plywood, 258–259
preservative treatment of, 259
shakes, 259
shingles, 259
square-edge, 257
types of, 265
vertical, 257–258
vertical-grain versus flat-grain,
255–256
wood windows, 246
woodworkers, problems
encountered by, xvii
Y
Y levels, 5–6
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