Plan Review Checklist Attachment

Plan Review Checklist Attachment
Floor Plan
1.
CONSTRUCTION DOCUMENTS & COMPLIANCE
TO APPROVED PLANS : IRC Section R106.
Approved site plans shall be attached to the approved
building plans during inspection. Property lines shall be
marked. Setback distances will be measured from the
furthest projection of the permitted structure.
Manufacturer’s installation instructions shall be available
on the job site at the time of inspection. All work shall be
installed in accordance with the approved construction
documents. Any changes made during construction that
are not in compliance with the approved construction
documents shall be resubmitted for approval as an
amended set of construction documents. To request
approval of revisions complete a “Request To Revise An
Approved Plan” form and submit to the Mason County
Permit Center along with approved plans and documents
detailing the proposed changes. R106
2.
EGRESS WINDOWS: IRC Section R311. All sleeping
rooms and basements with habitable space shall have at
least one openable emergency escape and rescue opening.
Such opening shall open directly into a public street,
public alley, yard or court. Emergency escape and rescue
openings shall have a minimum net clear opening of 5.7
square feet. Except that grade floor openings shall have a
minimum net clear opening of 5 square feet (see
definition below). The minimum net clear opening height
dimension shall be 24". The minimum net clear opening
width dimension shall be 20". The openings shall have a
maximum height of not more than 44" measured from
the finished floor to the bottom of the clear opening.
Emergency escape and rescue openings shall be
operational from the inside of the room without use of
keys or tools or special knowledge. Window wells shall
be provided when egress windows have a finished sill
height below adjacent ground elevation. The well shall
allow the window to be fully opened and provide a
minimum horizontal area of 9 sq. ft , with a minimum
horizontal projection and width of 36-inches. Window
wells with a vertical depth of more than 44" shall be
equipped with a permanent ladder. Grade floor opening
definition: A window or other opening located such that
the sill height of the opening is not more than 44” above
or below the finished ground level adjacent to the
opening. Refer to handout for additional information.
3.
SMOKE & CARBON MONOXIDE ALARMS: IRC
Section R314 & WAC R315. All smoke alarms shall be
listed in accordance with UL217 and installed in
accordance with the provisions of the International
Residential Code and the household warning equipment
provisions of NFPA 72. Smoke alarms shall be installed
in each sleeping room, outside each separate sleeping area
in the immediate vicinity of the bedrooms, in napping
areas of family child daycare homes, on each additional
story of the dwelling including basements and habitable
attics. Each story including basements and habitable
attics shall have at least one detector. When more than
one smoke alarm is required to be installed the alarm
devices shall be interconnected in such a manner that the
actuation of one alarm will activate all of the alarms in the
individual unit. The alarm shall be clearly audible in all
bedrooms over background noise levels with all
intervening doors closed. Required smoke alarms shall
receive their primary power from the building wiring
when such wiring is served from a commercial source and
when primary power is interrupted, shall receive power
from a battery. Additions, interior alterations, and repairs
shall be provided with smoke alarms as required for new
dwellings; the smoke alarms shall be interconnected and
hard wired. (Exception: Smoke alarms are not required to
be interconnected and hardwired where the alteration or
repairs does not result in the removal of interior wall or
ceiling finishes exposing the structure, unless there is an
attic, crawl space, or basement available which could
provide access for hard wiring and interconnection
without removal of hard finishes. Repairs to the exterior
surfaces of dwellings are exempt from these
requirements).
Carbon monoxide alarms are required by 1/01/11 in
all new residential construction. They shall be
installed outside of each separate sleeping room in the
immediate vicinity outside of the bedroom in the
dwelling and on each level of the dwelling in
accordance with manufacturer’s specifications.
4.
SAFETY GLAZING :R308.1 Each pane of glass
installed in a hazardous location shall be provided with a
manufacturer’s designation specifying who applied the
designation, designating the type of glass and the safety
glazing standard. The designation shall be visible in the
final installation and shall be acid etched, sand-blasted,
ceramic fired, laser etched, embossed or on that cannot be
removed without being destroyed.
R308.4 Hazardous locations. The following shall be
considered specific hazardous locations for the purposes
of glazing:
1. Glazing in all fixed and operable panels of
swinging, sliding and bifold doors.
Exceptions:
1. Glazed openings of a size through which
a 3-inch diameter (76 mm) sphere is unable
to pass.
2. Decorative glazing.
R308.4.2. Glazing in an individual fixed or operable
panel adjacent to a door where the nearest vertical
edge is within a 24-inch (610 mm) arc of the door in
a closed position and whose bottom edge is less than
60 inches
above the floor or walking surface.
Exceptions:
1. Decorative glazing.
2. When there is an intervening wall or other
permanent barrier between the door and the
glazing.
3. Glazing in walls on the latch side of and
perpendicular to the plane of the door in a
closed position.
4. Glazing where access through the door
is to a closet or storage area 3-ft or less in
depth.
5. Glazing that is adjacent to the fixed panel
of patio doors.
Glazing in walls and fences adjacent to indoor and
outdoor swimming pools, hot tubs and spas where
the bottom edge of the glazing is less than 60 inches
above a walking surface and within 60 inches,
measured horizontally and in a straight line, of the
water’s edge. This shall apply to single glazing and
all panes in multiple glazing.
R308.4.6. Glazing adjacent to stairways, landings
and ramps less than 36 inches above the plane of
the walking surface.
Exceptions:
1. When a rail is installed on the
accessible side(s) of the glazing 34 to
38 inches above the walking surface.
The rail shall be capable of
withstanding a horizontal load of 50
pounds per linear foot without
contacting the glass and be a minimum
of 11/2 inches in cross sectional height.
2. Glazing 36-inches or more measured
horizontally from the walking surface.
R308.4.3. Glazing in an individual fixed or operable
panel that meets all of the following conditions:
1. The exposed area of an individual pane is
larger than 9 square feet; and
2. The bottom edge of the glazing is less
than 18 inches above the floor; and
3. The top edge of the glazing is more than
36 inches above the floor; and
4. One or more walking surfaces are within
36 inches, measured horizontally and in a
straight line, of the glazing.
Exceptions:
1. Decorative glazing.
2. When a horizontal rail is installed on the
accessible side(s) of the glazing 34 to 38
inches above the walking
surface. The rail shall be capable of
withstanding a horizontal load of 50 pounds
per linear foot without contacting the glass
and be a minimum of 11/2 inches (38 mm)in
cross sectional height.
3. Outboard panes in insulating glass units
and other multiple glazed panels when the
bottom edge of the glass is 25 feet
or more above grade, a roof, walking
surfaces or other horizontal [within 45
degrees of horizontal] surface adjacent to
the glass exterior.
R308.4.7. Glazing adjacent to the stair
landing at the bottom of a stairway where the
glazing is less than 36-inches above the
landing and within 60 inches horizontally of
the bottom tread.
Exceptions:
1. The side of the stairway has a guardrail
or handrail, including balusters or in-fill
panels, complying with Sections R311.7.6
and R312 and the plane of the glass is
more than 18 inches from the guard.
5.
WINDOW OPENINGS:
FALL PROTECTION: IRC R312.2.1 Windowsills. In
dwelling units, where the opening of an operable window
is located more than 72 inches (1829 mm) above the
finished grade or surface below, the lowest part of the
clear opening of the window shall be a minimum of 24
inches (610 mm) above the finished floor of the room in
which the window is located. Operable sections of
windows shall not permit openings that allow passage of
a 4-inch diameter sphere where such openings are located
within 24 inches of the finished floor.
Exceptions:
1. Windows whose openings will not allow a 4-inchdiameter (102 mm) sphere to pass through the
opening when the opening is in its largest opened
position.
2. Openings that are provided with window fall
prevention devices that comply with ASTM F2090.
3. Windows that are provided with opening control
devices that comply with Section R312.2.2.
R308.4.4. All glazing in guards and railings
regardless of area or height above a walking surface,
including structural baluster panels and nonstructural
infill panels. Glass used as a handrail assembly or a
guard section shall be firmly supported on all edges.
As an option glazing not supported on alledges shall
be approved subject to detailed construction
documents, detailed shop drawings, and analysis or
test data assuring safe performance for the specific
installatation prepared by a registered design
professional shall be required. (ref IBC2403)
R308.4.5. Glazing and wet surfaces including
enclosures or walls facing hot tubs, whirlpools,
saunas, steam rooms, bathtubs and showers where the
bottom-exposed edge of the glazing is less than 60
inches measured vertically above any standing or
walking surface and less than 60-inches measured
horizontally in a straight line from the water’s edge
of a bathtub, hot spa, or whirlpool, or swimming
pool.
NATURAL LIGHT & VENTILATION: IRC R303. All
habitable rooms shall be provided aggregate-glazing area
2
of not less than 8% of the area of such rooms. Natural
ventilation shall be through windows, doors, louvers or
other approved openings to the outdoor air. The
minimum openable area to the outdoors shall be 4% of
the floor area being ventilated. Exception: 1) The glazed
area need not be openable where the opening is not
required by R310 (egress) and an approved mechanical
ventilation system is provided capable of producing .35
ACH in the room or a Whole house mechanical
ventilation system is installed capable of supplying
outdoor ventilation air of 15 cfm per occupant computed
on the basis of two occupants for the 1st bedroom and
one occupant for each additional bedroom. 2) The glazed
areas need not be provided in rooms where exception 1 is
satisfied and artificial light is capable of producing an
average illumination of 6 foot-candles over the area of the
room at a height of 30 inches above the floor level.
inches water gauge. Exhaust hoods shall be installed in
accordance with manufacturer installation instructions
and discharge to the outdoors. Single wall ducts shall
serving range hoods shall be constructed of galvanized
steel, stainless steel or copper or other approved material.
Such ducts shall have a smooth inner wall and be air tight
and equipped with a backdraft damper. Exhaust systems
capable of exhausting in excess of 400 cfm shall be
provided with make-up air at a rate approximately equal
to the exhaust air rate. Such makeup air system shall be
equipped with a means of closure and be automatically
controlled to start and operate with the exhaust system.
Clearance of at least 30-inches shall be maintained
between the cooking surface and the combustible material
or cabinet. Reduced clearances are permitted in
accordance with the listing and labeling of the range
hoods or appliances. Clearances to combustibles shall
include such considerations as door swing, drawer pull,
overhead projections or shelving and window swing,
coverings and drapes.
6.
EXHAUST FANS: IRC R303.4, Section M1501,
M1507. Exhaust fans are required in each kitchen, bathroom,
water closet room, laundry facility, indoor swimming pool,
spa and other rooms where excess water vapor or cooking
odor is produced. The air removed by every mechanical
exhaust system shall be discharged outdoors at a point where
it will not cause a nuisance and not less than the distances
specified in IMC Section 501.2.1. The air shall be discharged
to a location from which it cannot again be readily drawn in
by a ventilating system. Dryer exhaust ducts shall not be
exhausted into an attic or crawl space. The termination
point shall be located at least 3-feet from property lines,
3-feet in any direction from openings into the buildings
and 10-feet from mechanical air intakes. See energy
section of this checklist for more specific requirements.
9.
10. SHOWER and BATHTUB AREAS: IRC Section R307,
and UPC Sections 411, 414, 415, and 418. Bathtub and
shower floors and walls above bathtubs with installed
showerheads and in shower compartments shall be
finished with non-absorbent surfaces that extend to a
height of not less than 6-feet above the floor. The clear
space in front of the shower opening shall not be less than
24-inches. All showers shall have a minimum finished
interior floor area of 1024 square inches and shall be
capable of encompassing a 30-inch circle. The minimum
area and dimensions shall be maintained to a point 70"
above the shower drain outlet. Shower receptors shall
have curbs not less than 2-inches and not more than 9inches deep. The finished floor shall slope uniformly
toward the drain not less than ¼-inch vertical per foot
horizontal (2% slope) nor more than ½” per foot, and
floor drains shall be flanged to provide watertight joint in
the floor. On-site built-up shower receptors shall be lined
in accordance to UPC Section 411.8. Shower receptors
shall be tested for water tightness by filling with water to
the level of the rough threshold. A removable panel shall
be provided to access and remove whirlpool pumps.
Whirlpool pump access located in the crawl space shall
be located no more than 20-feet from an access door.
Showers and tub-shower combinations shall be provided
with individual control valves that provide scald and
thermal shock protection and shall conform to ASSE
1016. Hot water supplied to bathtubs, whirlpool bathtubs
and showers shall be limited to a maximum temperature
of 120oF. The water heater thermostat shall not be
considered a suitable control for meeting this provision.
7.
CLOTHES DRYERS: IRC Section M1502, G2439,
& IMC Section 504. Exhaust ducts, not less than 4-inch
diameter, shall be constructed of .016-inch-thick (28-gage)
rigid metal ducts, having smooth interior surfaces with joints
running in the direction of air flow. Exhaust ducts shall not be
connected with sheet-metal screws or fastening means that
extends into the duct and supported at intervals not less
than 12-ft. Transition ducts shall not be concealed within
construction. Flexible transition ducts used to connect the
dryer to the to the exhaust system shall be limited to single
lengths, not to exceed 8-feet and shall be listed and labeled in
accordance to UL 2158A. Exhaust ducts shall terminate
outside the building not less than 3-feet in any direction from
openings into buildings. Screens shall not be installed at the
duct termination. Ducts shall be equipped with a backdraft
damper. The maximum length of a clothes dryer exhaust duct
shall be in accordance with manufacturer specifications or
shall not exceed 35 feet from the dryer location to the wall or
roof termination. When fittings are used the maximum length
of the duct shall be reduced in accordance to Table
M1502.4.4.1. The maximum length of the exhaust duct does
not include the transition duct.
8.
WATER CLOSET: IRC Section R307, UPC Section
408, 402. Water closet shall be located in a clear space
not less than 30" in width. The clear space in front shall
not be less than 21-inches. Water closet seats shall be of
smooth, non-absorbent material. The maximum water use
allowed in gallons per flush (gpf) shall not exceed 1.6.
RANGE HOOD: IRC Section M1501, M1503, M1504,
M1505, M1901& M1306. All kitchens shall be provided
with exhaust hoods capable of exhausting 100 cfm at .25
3
stipulated in manufacturer’s listing. When masonry
chimneys are built within a structure, minimum 2”air
space clearance to combustible material is required.
When the chimney is placed on the exterior of the
structure, a 1" clearance is allowed. The air space shall
not be filled, except to provide noncombustible fire
blocking. All wood beams, joists, studs and other
combustible material shall have a clearance of not less
than 2” from the front faces and sides of masonry
fireplaces and not less than 4” from the back faces of
masonry fireplaces. The air space shall not be filled,
except to provide fireblocking in accordance to Section
R602.8 (see item #64). All spaces between chimneys and
floors and ceilings through which chimneys pass shall be
fireblocked with noncombustible material securely
fastened in place. The fireblocking of spaces between
chimneys and wood beams, joists, or headers shall be
self-supporting or be placed on strips of metal or metal
lath laid across the spaces between combustible material
and the chimney.. The air space shall not be filled, except
to provide fire blocking in accordance with sections
R1003.19. Woodwork or other combustible materials
shall not be placed within 6" of a fireplace opening.
Combustible material placed within 12" of the fireplace
opening (such as mantles or decorative fireplace
surrounds) shall not project more than 1/8" for each 1"
clearance from the opening.
11. CHIMNEYS & FIREPLACES: IRC Chapter 10.
R903.2.2, R905. After January 1, 1997 no new or used
factory-built fireplace, and new masonry or concrete
fireplace shall be installed in Washington State unless
certified and labeled in accordance with the procedures
and criteria specified in the Washington State Building
Code Standard 13-1. Contact the Olympic Region Clean
Air Agency (www.ORCAA.org) to obtain a list of
approved fireplaces and stoves. Factory-built chimneys
and fireplaces shall be labeled and installed in accordance
with the conditions of the listing. Factory built chimneys
installed in dwelling units with solid-fuel-burning
appliances shall comply with the HT requirements of UL
103 and shall be marked “Type HT and Residential Type
and Building Heating Appliance Chimney.” Masonry
chimneys: Masonry and concrete chimneys shall be
anchored at each floor, ceiling or roofline more than 6
feet above grade except where constructed completely
within exterior walls. A cricket or saddle shall be
installed on the ridge side of any chimney or penetration
more than 30-inches wide as measured perpendicular to
the slope. Cricket or saddle coverings shall be sheet
metal or of the same material as the roof covering.
Crickets shall be constructed in compliance with Figure
R1003.20 and Table R1003.20. See also seismic
anchorage requirements in IRC Section R1001.4.
Chimney flashing shall be applied according to the
asphalt shingle manufacturer printed instructions.
15. COMBUSTION AIR/EXTERIOR AIR SUPPLY: IRC
R303.4, R1001.7.1 (WAC), AND R1006. (WAC),
M1701 and G2407. Fuel burning appliances shall be
provided with combustion air obtained from outside the
structure ducted into the firebox. Direct vent appliances
or equipment that do not draw combustion air from inside
of the building shall be provided with combustion
ventilation and dilution air in accordance to the
manufacturer’s specifications. Fuel gas dryers shall be
provided with make-up air as directed by manufacturer
specifications. Solid-fuel-burning appliances shall be
provided with combustion air in accordance with the
manufacturer’s installation instructions. Oil-fired
appliances shall be provided with combustion air in
accordance to NFPA 31. Where required, outdoor
combustion air shall be provided in accordance to IRC
G2407.6. The minimum dimension of air openings shall
be not less than 3 inches. Two-permanent-openings
method: Two permanent openings, one commencing
within 12 inches of the top and one commencing within
12 inches of the bottom of the enclosure, shall be
provided.
The openings shall communicate directly, or by ducts,
with the outdoors or spaces that freely communicate with
the outdoors and have an opening of 1 sq- inch per 4,000
Btu/h of total input rating of all appliances in the
enclosure. Where communicating with the outdoors
through horizontal ducts, each opening shall have a
minimum free area of not less than 1 square inch per
2,000 Btu/h of total input rating of all appliances in the
enclosure. One-permanent-opening method: One
permanent opening, commencing within 12 inches of the
12. TIGHT-FITTING DOORS (FIREPLACE): R1006.2.
Solid fuel burning appliances and fireplaces shall be
provided with tight-fitting glass or metal doors. An
outside source for combustion air shall be ducted to the
firebox.
13. FIREPLACE HEARTH EXTENSION: IRC Sections
R1004.2, R1001.9. R1001.10 and R1004.2, M1414.2.
Hearth extensions of approved factory-built fireplaces
shall be installed in accordance with the listing of the
fireplace. The hearth extension shall be readily
distinguishable from the surrounding floor area. Masonry
fireplace hearths and hearth extensions shall be
constructed of concrete or masonry, supported by
noncombustible materials. Fireplace hearths shall be at
least 4” thick and hearth extensions shall be at least 2”
thick. The fireplace extension shall extend at least 16" in
front of, and at least 8" beyond each side of the fireplace
opening. Where the fireplace opening is 6 square feet or
larger, the hearth extension shall extend at least 20" in
front of, and at least 12" beyond each side of the fireplace
opening. Hearth extensions for fireplace stoves shall be
installed in accordance to the listing of the fireplace stove.
14. CLEARANCE TO COMBUSTIBLES &
FIREPLACE FIREBLOCKING: IRC Sections
R302.13, R1001.11, 1003.18, 1003.19, and M1306.2.1.
Combustible insulation shall be separated a minimum of
3” from heat producing appliances. Exception: Insulation
shall be separated in accordance with conditions
4
top of the enclosure, shall be provided. The appliance
shall have clearances of at least 1 inch from the sides and
back and 6 inches from the front of the appliance. The
opening shall directly communicate with the outdoors or
through a vertical or horizontal duct to the outdoors, or
spaces that freely communicate with the outdoors and
shall have a minimum free area of 1 square inch per 3,000
Btu/h of the total input rating of all appliances located in
the enclosure and not less than the sum of the areas of all
vent connectors in the space. Outside combustion air
openings shall be corrosion resistant screen or equivalent
protection having not less than ¼-inch openings and not
greater than ½” openings. Unless otherwise specified by
the manufacturer or determined by actual measurement,
the free area shall be considered 75% of the gross area for
metal louvers and 25% of the gross area for wood
louvers. Volume dampers (manual dampers) shall not be
installed in combustion air openings. Openings shall be
covered with corrosion-resistant screen, not less than ¼inch openings and not greater than ½-inch openings.
Outdoor air openings for fuel-burning appliances are
permitted to connect spaces such as ventilated crawl
spaces or ventilated attic spaces, provided those spaces
can provide unobstructed openings to the outdoors. The
exterior air intake shall not be located within the garage
or basement of the dwelling nor shall the air intake be
located at an elevation higher than the firebox.
Mechanical and gravity outside air intake openings shall
be located a minimum of 10’ from any hazardous or
noxious contaminant, such as vents, chimneys, plumbing
vents, streets, alleys, parking lots and loading docks.
Where a source of contaminant is located within 10’ of an
intake opening, such opening shall be located a min. of 2’
below the contaminant source. Exhaust from dwelling
units, toilet rooms, bathrooms and kitchens shall not be
considered as hazardous or noxious.
appliance. Appliances shall not be installed in a location
where subject to mechanical damage unless protected by
approved barriers. Appliances designed to be in fixed
positions shall be anchored or strapped to resist horizontal
displacement caused by earthquake motion in an
approved manner. Strapping shall be at points within the
upper 1/3 and lower 1/3 of the appliances vertical
dimensions. At the lower point the strapping shall
maintain a minimum distance of 4-inches above the
controls.. Fuel-fired furnaces and boilers installed in
closets and alcoves shall be listed for such installation.
Equipment installed in outdoor locations shall be either
listed for outdoor installation or provided with protection
from outdoor environment factors that influence
operability, durability and safety of the equipment.
Appliances installed in a compartment, alcove, basement
or similar space shall be accessed by an opening or door
and an unobstructed passageway measuring not less than
24-inches wide and large enough to allow removal of the
largest appliance in the space, provided there is a level
service space of not less than 30-inches deep and the
height of the appliance, but not less than 30-inches, at the
front or service side of the appliance with the door open.
Attics containing appliances requiring access shall have
an opening and a clear unobstructed passageway large
enough to allow removal of the largest appliance, but not
less than 30-inches high and 22-inches wide and not more
than 20-feet long when measure from the opening to the
appliance. The passageway shall have continuous solid
flooring not less than 24-inches wide. A level service
space at least 30-inches x 30-inches along all sides.
Appliances located in under floor spaces shall have an
unobstructed passageway large enough to remove the
largest appliance, but not less than 30-inches high and 22inches wide, nor more than 20-feet long, measured from
the opening to the appliance. A level service space at least
30-inches x 30-inches along all sides. If the service space
exceeds 12-inches below the adjoining grade, the walls on
the passageway shall be lined with concrete or masonry
extending 4-inches above the adjoining grade. Appliance
supported from the ground shall be level and firmly
supported on a concrete slab. Appliances suspended from
the floor shall have a clearance of not less than 3-inches
from the ground in stalled in accordance to manufacturer
specifications. A luminaire, controlled by a switch at the
passageway opening shall be installed near under floor
and attic appliances and a receptacle outlet shall be
installed at or near the appliance location.
16. APPLIANCE INSTALLATION: IRC Chapter M12,
Chapter M 13, M2005, G2406. Appliances shall be
listed and labeled for the application in which they are
installed and used. A permanent factory-applied
nameplate shall be affixed to appliances with information
listed in accordance to M1303. The standards for
liquefied petroleum gas installations shall be in
accordance with NFPA 58 (Liquefied Petroleum Gas
Code) and the International Fuel Gas Code. The
manufacturer’s operating and installation instructions
shall remain attached to the appliance. Fuel-fired
appliances shall not be located in sleeping rooms,
bathrooms, toilet rooms, or storage closets. Exception: 1)
direct vent appliances that obtain all combustion air from
the outdoors. Where combustion air is obtained from a
dedicated enclosure in which combustion air is taken
directly from the outdoor in accordance to G2407, access
to such enclosure shall be through a WSEC approved
solid door, weather-stripped and equipped with an
approved self-closing device. Appliances shall be
accessible for inspection, service, repair, and replacement
without removing permanent construction, other
appliances, or other piping or ducts not connected to the
17. APPLIANCES LOCATED IN GARAGE: IRC Section
M1307. Appliances located in a garage, carport or other
location where subject to mechanical damage shall be
protected with approved barriers. Vehicle barrier systems
for passenger cars shall be designed to resist a single load
of 6,000 lbs. Applied horizontally in any direction to the
barrier system and shall have anchorage or attachment
capable of transmitting this load to the structure. For
design of the system, the load shall be assumed to act at a
minimum height of 1’6” above the floor or ramp surface
on an area not to exceed 1 sq. ft.
5
accordance with G2406.2. Appliances installed in pits or
excavations shall not come in direct contact with the
surrounding soil. The sides of the pit shall be held back a
minimum of 12” from the appliance. Where the depth
exceeds 12” below the adjoining grade, the walls of the
pit or excavation shall be lined with concrete or masonry.
Containers used for storage of LPG shall be installed in
accordance with the Fire Code, see details attached.
Equipment and appliances having an ignition source shall
be elevated such that the source of ignition is not less than
least 18" above the floor surface on which the equipment
or appliance stands unless the appliance is listed as
flammable vapor ignition resistant. Rooms or spaces that
are not part of the living space of a dwelling unit and that
communicate with the private garage through openings
shall be considered to be part of the garage and
appliances located in the space shall be elevated as
specified above.
20. MANUFACTURER'S SPECS: IRC Section M1302,
M1303.1, M1307, and IMC 304.1. All appliances shall
be listed and bear a permanent factory applied
nameplate(s) affixed to the appliances with
manufacturer’s name or trademark, model number, serial
number, and seal or mark of testing agency. The installer
shall leave the manufacturer's installation and operating
instructions attached to the appliance.
18. WATER HEATERS: UPC Chapter 5 & 608, IRC
Section M1307.2, M2005 & IECC/WSEC R403.4. When
water heaters or hot water storage tanks are installed in
locations where leakage of the tanks or connections will
cause damage, the tank or water heater shall be installed
in a watertight pan of corrosion resistant material. The
pan shall be at least 1.5” deep and with a ¾”diameter
drain to the exterior of the building not less than 6” and
not more than 24” above the adjacent ground surface.
Temperature and pressure relief valves shall be drained to
the outside of the building. Drain may not be trapped and
must terminate not more than 2’ nor less than 6" above
the ground or the flood level of the area receiving the
discharge and pointing downward. Water heaters shall be
anchored or strapped to resist horizontal displacement due
to earthquake motion. Twenty-two (22) gage x ¾”
strapping shall be used and be placed at points within the
upper one-third (1/3) and lower one-third (1/3 ) of it’s
vertical dimensions. At the lower point, a minimum
distance of 4” shall be maintained above the controls.
Lag screws not less than ¼” in diameter must be used to
anchor the restraints to the wall and each lag screw must
have at least 1-½” thread penetration into a stud wall. A
flat washer must be installed between each lag screw and
the strap for reinforcement. When the water supply
system is provided with a pressure regulating device or
check valve a properly sized expansion tank shall be
installed per manufacturer specifications. Check with
your water purveyor. Water heaters used to supply both
potable hot water and hot water for space heating shall be
installed in accordance with manufacturer’s installation
instructions. In addition combination space and service
water heaters shall have an Energy Factor (EF) or
Combined Annual Efficiency (CAE) not less than that
specified in WSEC Section 504.2.1. Service water
heating systems shall be equipped with automatic
temperature controls and shall be set to 120oF. WSEC
Section 504.2.1 requires that all electric water heaters
shall be placed on an R-10 pad when located in an
unheated space or on a concrete floor.
21. VACUUM BREAKERS: UPC Sections 603.4.7.
Potable water outlets with hose attachments other than
water heater drains, and clothes washer connections shall
be protected by a listed non-removable backflow
preventor, a non-removable frost-free hose bib type
vacuum breaker, or an atmospheric vacuum breaker
installed at least 6” above the highest point of usage
located on the discharge side of the last valve.
22. TRAP PRIMERS, DISHWASHER AIRGAP: UPC
Section 1007 & 807.4. Floor drains or similar traps
connected to the drainage system and subject to
infrequent use shall be protected with a trap seal primer
and shall be accessible for maintenance. All dishwashers
connected to a drainage system or food waste disposer
shall be equipped with an approved air gap fitting on the
discharge side of the dishwashing machine. Listed air
gaps shall be installed with the flood-level marking at or
above the flood-level of the sink or drain board,
whichever is higher.
23. GARAGE/DWELLING DOOR/OPENINGS: IRC
Section R302.5.1 Openings between the garage and
residence shall be equipped with self-closing, solid wood
doors not less than 1-3/8 inches (35mm) in thickness,
solid or honeycomb core steel doors not less than 1-3/8”
thick, or 20-minute fire-rated doors.
24. GARAGE/DWELLING SEPARATION: IRC Section
R302.5 R302.6,. The garage shall be separated from the
residence and its attic area by not less than ½” gypsum
board applied to the garage side. Garages beneath
habitable rooms shall be separated from all habitable
rooms above by not less than 5/8” Type X gypsum board
or equivalent. Where the separation is a floor-ceiling
assembly, the structure supporting the separation shall
also be protected by not less than ½” gypsum board or
equivalent. Ducts in the garage and ducts penetrating the
walls or ceilings separating the dwelling from the garage
shall be constructed of a minimum 26-gage sheet metal or
other approved material and shall have no openings into
the garage. Penetrations shall be protected by filling the
19. LPG (PROPANE) APPLIANCES & TANKS: IFGC
303, NFPA 58, IRC M1301, IRC Chapter G24, & IMC
Section 303.7 and IFGC303.7. Appliances shall be
installed in accordance with the manufacturer listing .
Fuel-gas appliances shall not be located in sleeping
rooms, bathrooms, toilet rooms, storage closets or in a
space that opens only into such rooms unless allowed in
6
opening around the penetrating item with approved
material to resist the free passage of flame and products
of combustion. Garages located less than 3-feet from a
dwelling unit on the same lot shall be protected with not
less than ½-inch gypsum board applied to the interior side
of the exterior walls that are within this area. Openings
shall meet the same protection as required in R302.5.
required floor area may have a ceiling height of less than
5-feet. 2) Bathrooms shall have a min. ceiling height of
6’8” over the fixture and at the front clearance area for
fixtures as shown in figures R307.1. The ceiling height
above fixtures shall be such that the fixture is capable of
being used for it’s intended purpose. A shower or tub
equipped with a showerhead shall have a minimum
ceiling height of 6’8” above the area 30-inches x 30inches at the showerhead. Portions of basements that do
not contain habitable space, hallways, bathrooms, toilet
rooms and laundry rooms may project to within 6’8” of
the finished floor. Exception: beams, girders, ducts or
other obstructions may project within 6’4” of the finished
floor
25. SEPARATION BETWEEN DWELLING UNITS: IRC
Section R302.3. Walls and floors assemblies separating
dwelling units in 2-family dwellings shall not be less than
1-hr fire-resistive rating.
26. FIRE-RESISTANCE OF EXTERIOR WALLS:
Washington State Amendment to R302.1, Tables R302.1
and R302.1(2). Exterior walls with a fire separation
distance less than 5-feet shall have not less than a 1-hour
fire-resistive rating with exposure from both sides.
Openings are not permitted at less than 3-ft and limited
when located between 3-ft to 5-ft. Projections shall not
extend to a point closer than 2-feet from the line used to
determine the fire separation distance. When a structure
is equipped with an automatic fire-sprinkler system
installed in accordance with P2904 fire-resistive
ratings may be reduced in accordance with Table
R302.1(2). Exception: Detached garages accessory to a
dwelling located within 2-ft of a lot line may have roof
eave projections not exceeding 4”. Projections extending
into the fire separation distance shall have not less than
one-hour fire-resistive construction on the underside.
These provisions shall not apply to walls perpendicular to
the line used to determine the fire separation distance.
Exception: Tool and storage shed, playhouses and similar
structures exempted from permits by R105.2 or Mason
County ordinance are not required to provide wall
protection based on location on the lot. Projections
beyond the wall line shall not extend over the lot line. .
Exception: Foundation vents installed in compliance with
this code are permitted.
29. ATTIC ACCESS: IRC R807.1. Buildings with
combustible ceiling or roof construction shall have an
attic access openings to attic areas that exceed 30 sq. ft.
and have a vertical height of 30". Minimum access
openings shall not be less than 22" x 30". The attic
access shall be located in a hallway or other readily
accessible location with a 30” minimum unobstructed
headroom in the attic space above the access opening.
30. EXTERIOR DOORS/EXITS: IRC R311. At least one
egress door shall be provided to each dwelling. The
egress door shall be side-hinged and with a min. clear
width of 32-inches in width and not less than 78-inches in
height, measured from the top of the threshold to the
bottom of the stop. The exit door shall provide direct
access from the habitable portions of the dwelling to the
exterior without requiring travel through a garage. Egress
from habitable levels including habitable attics and
basements not provided with an egress door shall be by a
ramp or a stairway in accordance to applicable IRC
sections 311.8 or 311.7. Egress doors shall be readily
openable from the side from which egress is to be made
without the use of a key or special knowledge or effort.
31. LANDINGS AT DOORS AND STAIRWAYS &
CONSTRUCTION: IRC R311.3, R311.5. The floor or
landing at the required egress door shall not be more
than 1-1/2” lower than the top of the threshold.
Exception:The landing on the exterior side shall not be
more than 7-3/4” below the top of the threshold
provided the door does not swing over the landing or
floor. Storm and screen doors are allowed to swing
over all exterior stairs and landings. When exterior
landings or floors serving the required egress door are not
at grade, they shall be provided with access to grade by
means of a ramp or stairway. There shall be a floor or
landing on each side of all other exterior doors. Floor
elevations for the doors shall be provided with landings
no more than 7-3/4” below the top of the threshold.
Exception: A landing is not required where a stairway of
two or fewer risers is located on the exterior side of the
door, provided the door does not swing over the stairway.
Storm and screen doors are permitted to swing over all
exterior stairs and landings The width of each landing
shall not be less than the door served and shall have a
27. FLOOR AREA: IRC Section R304, R306. Every
dwelling unit shall have at least one habitable room with
not less than 120 square feet of gross floor area. Other
habitable rooms except kitchens shall have an area of not
less than 70 square feet. Habitable rooms shall not be less
than 7-feet in any dimension. Exception: Kitchens.
Every dwelling unit shall be provided with a water closet,
lavatory, bathtub or shower, kitchen area with a separate
sink, be connected to an approved sewage disposal
system, and shall be connected to an approved water
supply with hot and cold water.
28. MINIMUM CEILING HEIGHTS: IRC R305.
Habitable rooms, hallways, corridors, bathrooms, toilet
rooms, laundry rooms and basements shall have a ceiling
height of not less than 7-feet, measured from the finished
floor to the lowest projection from the ceiling.
Exceptions: 1) For rooms with sloped ceilings, at least
50% of the required floor area of the room must have a
ceiling height of at least 7-feet and no portion of the
7
min. dimension of 36-inches measured in the direction of
travel. The floor or landing at the exterior door shall not
be more than 1 ½” lower than the top of the threshold.
The landing shall be permitted to have a slope not to
exceed 1/4 unit vertical in 12 units horizontal (1:48). A
flight of stair shall not have a vertical rise greater than 12feet between floor levels or landings. Landings shall be
the same width of the stairway served and at least 36inches measured in the direction of travel.
handrail. TYPE I: Circular handrails shall have an
outside diameter of at least 1 ¼” and not greater than 2”.
If the handrail is not circular, it shall have a perimeter
dimension of at least 4” and not greater than 6 ¼” with a
maximum cross-section dimension of 2 ¼”. TYPE II:
Handrails with a perimeter greater than 6 ¼” shall have a
graspable finger recess area on both sides of the profile.
The finger recess shall begin a distance of ¾” measured
vertically from the tallest portion of the profile and
achieve a depth of at least 5/16” within 7/8” below the
widest portion of the profile. This required depth shall
continue for at least 3/8” to a level that is not less than 1
¾” below the tallest portion of the profile. The minimum
width of the handrail above the recess shall be 1 ¼” to a
maximum of 2 ¾”. Edges shall have a minimum radius
of .01”. See item #34, stairway width, for additional
information. Also refer to deck detail information
attached to this checklist.
Exterior landings, decks, balconies, stairs, and similar
facilities shall be positively anchored to the primary
structure to resist both vertical and lateral forces or shall
be designed to be self-supporting. Attachments shall not
be accomplished by use of toenails or nails subject to
withdrawal. See also item #69 for deck attachment info.
32. GUARDS: IRC Section R312. Table R301.5 Guards
shall be provided for porches, balconies, ramps, or raised
floor surfaces located more than 30" above grade or a
floor below. Grade shall be measured 36-inches
horizontally from the edge of the floor surface. Guards
shall be not less than 36” in height, measured from the
adjacent walking surface, adjacent fixed seating or the
line connecting the leading edges of a tread. Exception:
1) Open sides of stairs with a total rise of more than 30”
above the floor or grade below shall have guards not less
than 34” in ht. measured vertically from a line
connecting the leading edges of the treads. 2) Where the
top of the guard also serves as a handrail on the open
sides of stairs, the top of the guard shall not be less than
34” and not more than 38” above the leading edge of
treads. Required guards shall be designed such that a
sphere 4" in diameter cannot pass through. Exceptions:
1) The triangular openings at the open side of a stair,
formed by the riser, tread and bottom rail of a guard are
permitted to be of such size that sphere 6-inches cannot
pass through. 2) Guards on the open sides of stairs shall
not have openings which allow passage of a sphere 43/8” in diameter. Handrail assemblies and guards shall
be able to resist a single concentrated load of 200 lbs.,
applied in any direction at any point along the top, and
have attachment devices and supporting structure to
transfer this loading to appropriate structural elements of
the building. Intermediate rails (all those except the
handrail), balusters and panel fillers shall be designed to
withstand a horizontally applied normal load of 50 lbs. on
an area equal to 1 sq. ft., including openings and space
between rails.
34. STAIR WIDTH: IRC Section R311.7.1 Stairways shall
not be less than 36” in clear width at all points above the
handrail height and below the required headroom height.
Handrails shall not project more than 4 ½” on either side
of the stairway and the minimum clear width of the
stairway at and below the handrail height, including
treads and landings, shall not be less than 31 ½” where
the handrail is installed on one side and 27” where
handrails are installed on both sides. Width of spiral
stairways shall be in accordance with Section R311.7.9.1,
see item #39.
35. STAIR TREADS & RISERS and RAMP SLOPE: IRC
Section R311.7.5 & R311.8.1 The maximum riser height
shall be 7 ¾”. The greatest riser height within any flight
of stairs shall not exceed the smallest by more than 3/8”.
The minimum tread depth shall be 10”. The tread depth
within any flight of stairs shall not exceed the smallest by
more than 3/8”. A nosing not less than ¾” but not more
than 1 ¼” shall be provided on stairways with solid risers.
Open risers are permitted, provided that the opening does
not permit the passage of a 4” diameter sphere.
Exception: Nosing is not required where the tread depth
is at least 11”. The opening between adjacent treads is
not limited on stairs with a total rise of 30” or less.
Ramps shall have a maximum slope of 1 unit vertical in
12 units horizontal.
36. STAIR HEADROOM CLEARANCE: IRC R311.7.2
All parts of the stairway shall not be less than 6’8”
measured vertically from the sloped plane adjoining the
tread nosing or from the floor surface of the landing or
platform. See exception for spiral stairways.
33. HANDRAILS: IRC Section R311.7.8, R311.8.3 All
stairways with 4 or more risers shall have at least one
handrail. Such handrails shall be placed not less than 34"
and not more than 38" above the nosing of the treads.
Handrails for stairways shall be continuous for the full
length of the flight, from a point directly above the top
riser to a point directly above the lowest riser. Handrail
ends shall be returned or terminate in newel posts or
safety terminals. Handrails adjacent to the wall shall have
a space not less than 1 ½” between the wall and the
37. UNDER STAIR PROTECTION: IRC Section R302.7
Enclosed accessible space under stairs shall have walls,
under stair surface and any soffits protected on the
enclosed side with ½” gypsum board.
38. ILLUMINATION: IRC Section R303.7. All interior
and exterior stairways shall be provided with a means to
8
illuminate the stairs, including landings and treads.
Stairway illumination shall receive primary power
from the building wiring. Interior stairways shall be
provided with an artificial light source located in the
immediate vicinity of each landing of the stairway.
Exterior stairways shall be provided with a light source
located in the immediate vicinity of the top of the landing
of the stairway. Exterior stairways providing access to a
basement from the outside grade level shall be provided
with an artificial light source located in the immediate
vicinity of the bottom landing of the stairway. Where
lighting outlets are installed in the interior stairways,
there shall be a wall switch at each floor level to control
the lighting outlet where the stairway has 6 or more risers.
The illumination of exterior stairways shall be controlled
from inside the dwelling unit
permitted to be supported by isolated plain concrete
footings supporting columns or pedestals.
41. FOOTING REINFORCEMENT: IRC Section R403.1,
Standard Hook ACI Section 611.7.1.5. Concrete footings
shall have bottom reinforcement located a minimum of 3inches clear from the bottom of the footing. Where a
construction joint is created between a concrete footing
and stem wall, a min. #4, grade 60, vertical bar shall be
provided at not more than 4-feet on center. The vertical
bar shall extend to 3-inches clear of the bottom of the
footing, have a standard hook and extend a minimum of
14-inches into the stem wall. The standard hook shall
have a 3-inch return and shall engage the center-footing
bar. The vertical bar shall be tied in place at inspection.
As a minimum standard, refer to the attached handouts:
Foundation Reinforcement Requirements.
39. SPECIAL STAIRWAYS: IRC Section R311.4,
R311.7.10, R311.7.5.2.1, . Spiral stairways and bulkhead
enclosure stairways shall comply with all requirements of
stairways except: Spiral stairways are permitted, provided
the minimum width below the handrail shall be 26 inches
with each tread having a 7 ½” minimum tread depth at
12” from the narrower edge. All treads shall be identical,
and the rise shall be no more than 9 ½”. A minimum
headroom of 6 feet 6 inches shall be provided. Stairways
serving bulkhead enclosures see IRC Section
R311.7.10.2. The walk line across winder treads shall be
concentric to the curved direction of travel through the
turn and located 12” from the side where the winders are
narrower. The 12” dimension shall be measured from the
widest point of the clear stair width at the walking surface
of the winder. If winders are adjacent within the flight,
the point of the widest clear stair width of the adjacent
winder shall be used. Winder treads shall have a
minimum tread depth of 10” between the vertical planes
of the foremost projection of adjacent treads at the
intersections with the walk line. Winder treads shall
have a minimum tread depth of 6” at any point within the
clear width of the stair. Note: Washington State
Amendment to IRC R311.4: Stairs and ladders are
permitted within an individual dwelling unit used for
access to areas of 200 sq. ft. or less, and not containing
the primary bathroom or kitchen.
42. FOUNDATION WALL SIZE: IRC R403.1.3.1, R404,
Tables R404.1.1(1) through R404.1.1(4), & Section
404.1.4 See attached handouts. Concrete and plain
masonry foundation walls located in Seismic Design
Categories D2, as established in Table R301.1(1), shall
comply with the following: 1) Minimum reinforcement
shall consist of one #4 horizontal bar located in the upper
12” of the wall (two bars if wall greater than 8’ in height),
2) Wall height shall not exceed 10’, 3) Height of
unbalanced backfill shall not exceed 4’0” (except per
table 404.1.1(5)), and 4) A minimum thickness of 7 ½” is
required for concrete foundation walls except that a
minimum thickness of 6” shall be permitted for concrete
foundation walls with a maximum height of 4’6”
provided the minimum specified compressive strength of
concrete, fc, is 3000 psi. 5) Masonry foundation walls
shall be a minimum of 8” thick.
Vertical reinforcement for masonry stem walls shall be
tied to the horizontal reinforcement in the footings.
Masonry stem walls located in Seismic Design Categories
D2 shall have a min. vertical reinforcement of one #4 bar
located a max. of 4’ o.c. in grouted cells.
Foundation walls located in Seismic Design Categories
D2, as established in Table R301.2(1), supporting more
than 4’ of unbalanced backfill or exceeding 8’ in
height shall be constructed in accordance with Table
R404.1.1(5) and shall have two #4 horizontal bars located
in the upper 12” of the wall.
As a minimum standard, refer to the attached handouts:
Foundation Reinforcement Requirements.
40. FOUNDATION FOOTING SIZE: IRC Section R403.
Assume load-bearing value of soil 1500 psf unless proven
otherwise. All exterior walls shall be supported on
continuous footings placed on undisturbed natural soils or
engineered fill. All required interior braced wall panels
shall be supported on footings at intervals not exceeding
50-ft.
 Supporting 1 story: minimum 6"x 12".
 Supporting 2 story: minimum 6" x 15".
 Supporting 3 story: minimum 8" x 23".
43. STEPPED FOUNDATIONS: IRC Section 602.11.2.
Where the height of a required braced wall line that
extends from the foundation to floor above varies more
than 4’, the braced wall panel shall be constructed in
accordance to figure R602.11.2 and as follows: See
attached details. 1) Where the lowest floor framing rests
directly on a sill bolted to a foundation not less than 8’ in
length along a line of bracing, the line shall be considered
as braced. The double plate of the cripple stud wall
beyond the segment of footing that extends to the lowest
framed floor shall be spliced by extending the upper top
Spread footing projections shall be at least 2” & shall not
exceed the thickness of the footing . R403.1.3 Interiorstud-bearing walls, supporting 3-stories or less, are
9
plate a minimum of 4’ along the foundation. Anchor
bolts shall be located a maximum of 1’ and 3’ from the
step foundation. 2) Where cripple walls occur between
the top of the foundation and the lowest floor framing, the
bracing requirements for a story shall apply, see
R602.10.9 and R602.10.9.1 3) Where only the bottom of
the foundation is stepped and the lowest floor framing
rests directly on a sill bolted to the foundations, the
requirements of R403.1.6 and R602.11.1 shall apply. See
item #46.
wall lines sills and sole plates shall be protected against
decay. The hole in the plate washer is permitted to be
diagonally slotted with a width of up to 3/16” larger than
the bolt diameter and a slot length not to exceed 1-3/4 “,
provided a standard cut washer is placed between the
plate washer and the nut..
47. DAMP-PROOF FOUNDATION WALLS: IRC Section
R406. Except where required to be waterproofed by
section R406.2, foundation walls that retain earth and
enclose interior or usable spaces located below grade
shall be damp proofed from the top of the footing to the
finished grade. R406.2: In areas where a high water
table or other severe soil-water conditions are known to
exist, exterior foundation walls that retain earth and
enclose usable spaces located below grade shall be
waterproofed with a membrane extending from the top of
the footing to the finished grade. The membrane shall
consist of 2-ply hot mopped felts, 55-pound roll roofing,
6-mil polyvinyl chloride, 6-mil polyethylene, 40-mil
polymer-modified asphalt or 60-mil flexible polymer
cement. The joints in the membrane shall be lapped and
sealed with an adhesive compatible with the
waterproofing membrane. See exceptions for additional
information.
44. FOOTING DEPTH: IRC Section R403.1.4.1, 403.1.4.2.
all exterior footings shall be placed at least 12” below
undisturbed ground. Interior footings supporting bearing
or bracing walls and cast monolithically with a slab on
grade shall extend to a depth of less than 12” below the
top of slab.
45. BRACED WALL PANEL SUPPORT/CRIPPLE
WALL BRACING: IRC Definition, Sections R602.9,
R602.10.9.1, R602.10.11, One story buildings in
seismic design category D2 shall be supported on
continuous foundations at intervals not to exceed 50ft. In two-story buildings ALL interior braced wall
panels shall be supported by cripple walls that do not
exceed 4-ft, 1st floor braced panels supported by
double joists, continuous blocking or floor beams and
the distance between wall bracing does not exceed
twice the building width. Cripple walls defined as the
framed wall extending from the top of the foundation
to the underside of the floor framing of the story
above, shall be constructed with wood structural
panels with the length and method specified in Table
R602.10.3(3) and R602.10.3(4). Adhesive attachment
of wall sheathing shall not be permitted in Seismic
Design Categories D2.
48. FOUNDATION DRAINAGE: IRC Section R401.3,
R405. Surface drainage shall be diverted to an approved
point of collection so as to not create a hazard. Lots shall
be graded so as to drain surface water away from
foundation walls. The grade away from foundation walls
shall fall a minimum of 6” within the first 10.’ Exception:
Where lot lines, walls, slopes or other physical barriers
prohibit 6” of fall within 10’ drains or swales shall be
provided to ensure drainage away from the structure.
Impervious surfaces within 10-ft of the building
foundation shall be sloped a min. 2% away from the
building. Drains shall be provided around all concrete or
masonry foundations that retain earth and enclose
habitable spaces located below grade. Drainage tiles,
gravel, or crushed stone drains, perforated pipe or other
approved systems or materials shall be installed at or
below the area to be protected and shall discharge by
gravity or mechanical means into an approved drainage
system. Gravel or crushed stone drains shall extend at
least 1-foot beyond the outside edge of the footing and at
least 6 inches above the top of the footing and be covered
with an approved filter membrane material. The top of
open joints of drain tiles shall be protected with strips of
building paper, and the drainage tiles or perforated pipe
shall be placed on a minimum 2 inches of washed gravel
or crushed rock at least one sieve larger than the tile joint
opening or perforation and covered with not less than 6
inches of the same material.
46. FOUNDATION ANCHORAGE: IRC Section 403.1.6,
R602.11. Braced wall panels shall be supported directly
on continuous foundations. The wood sole plates at
exterior walls on monolithic slabs and wood sill plates
shall be anchored to the foundation with ½”anchor bolts
spaced a maximum of 6’o.c. and shall extend a minimum
of 7” into concrete or grouted cells of concrete masonry
units. The maximum anchor bolt spacing shall be 4-ft for
buildings over two stories in height. There shall be 2 bolts
per plate section with one bolt located not more than 12”
or less than 7 bolt diameters (3 ½” typical) from each end
of the plate section. Where interior braced wall lines are
required (seismic zones D1 & D2) to be supported by
continuous foundations in Section 403.1.2, ½” anchor
bolts shall be spaced not more than 6’ o.c. and located
within 12” from the ends of each plate section. Anchor
bolts shall be at least ½” in diameter and shall extend a
minimum of 7” into masonry or concrete. Interior
bearing wall sole plates on monolithic slab foundations
shall be positively anchored with approved fasteners. A
nut and washer shall be tightened on each bolt to the
mudsill plate using ¼” x 3” x 3” plate washers except
where approved anchor straps are used. At all braced
49. FOOTING/PIERS ON OR ADJACENT TO SLOPES:
IRC Section 403.1.7. The placement of buildings and
structures on or adjacent to slopes steeper than 1 unit
vertical in 3 units horizontal (33.3-percent slope) shall
conform to Sections R403.1.7.1 through R403.1.7.4.
10
Buildings below slopes shall be set a sufficient distance
from the slope to provide protection from slope drainage,
erosion and shallow failures. Where the existing slope is
steeper than one unit vertical in one unit horizontal (100%
slope), the toe of the slope shall be assumed to be at the
intersection of the horizontal plane drawn from the top of
the foundation and a plane drawn tangent to the slope at
an angle 45 degrees to the horizontal. Where a retaining
wall is constructed at the toe of the slope, the height of
the slope shall be measured from the top of the wall to the
top of the slope. Footings on or adjacent to slopes shall
be founded in material with an embedment and setback
from the slope surface to provide vertical and lateral
support for the footing without detrimental settlement.
Except as provided for in Section R403.1.7.4 and Figure
R403.1.7.1, the following setback is deemed adequate to
meet the criteria. Where the slope is steeper than one unit
vertical in one unit horizontal (100% slope), the required
setback shall be measured from an imaginary plane 45
degrees to the horizontal, projected upward from the toe
of the slope. Footings adjacent to slopes shall be founded
in firm material with an embedment and setback
sufficient to provide vertical and lateral support for the
footing without detrimental settlement. Alternate
setbacks and clearances are permitted, subject to the
approval of the building official. The building official is
permitted to require an investigation and recommendation
of a qualified engineer to demonstrate that the intent of
the code has been satisfied. Such an investigation
(geotechnical evaluation) shall include consideration of
material, height of slope, slope gradient, load intensity
and erosion characteristics of slope material. Exception:
Mason County Development Regulations may specify
additional requirements.
ventilating opening shall be within 3-feet of each corner
of the building, except one side of the building shall be
permitted to have no ventilation openings. Ventilation
openings shall be covered for their height and width with
any of the following materials provided that the least
dimension of the covering shall not exceed ¼”: 1)
perforated sheet metal plates not less than .070” thick, 2)
Expanded sheet metal plates not less than .047” thick, 3)
Cast iron grills or grating, 4)Extruded load-bearing brick
vents, 5) Hardware cloth of .035” wire or heavier, 6)
Corrosion-resistant wire mesh, with the least dimension
being 1/8”. See exceptions for additional options.
52. WOOD IN CONTACT WITH CONCRETE &
MASONRY: IRC Section R317.1 #2. All wood framing
members that rest on concrete or masonry exterior
foundation walls and are less than 8” from the exposed
ground require the use of naturally durable wood or
wood that is preservative treated accordance with AWPA
U1 for the species, product, preservative, and end use.
Preservatives shall be listed in Section 4 of AWPA U1.
53. COLUMNS AND POSTS: IRC Section R317.1.2,
R317.1.4 & R407.3. Posts, poles and columns supporting
permanent structures that are embedded in concrete in
direct contact with the ground, or embedded in concrete
exposed to the weather shall be approved pressure
preservatively treated or wood suitable for ground
contact.
Wood columns shall be approved wood of natural decay
resistance or approved pressure preservatively treated
wood. Exceptions: 1) Posts or columns which are
exposed to the weather or located in basements or cellars,
supported by concrete piers or metal pedestals projecting
1” above the floor or finished grade and 6” above
exposed earth, and are separated by an approved
impervious moisture barrier. 2) Posts or columns in
enclosed crawl spaces or unexcavated areas located
within the periphery of the building, supported by a
concrete pier or metal pedestal at a height greater than 8”
from the exposed earth and the earth is covered by an
impervious moisture barrier.
50. CHIMNEY FOUNDATION & SEISMIC
REINFORCING: IRC Sections 1001, R1001.2, When
an approved design is not provided, footings for masonry
and concrete fireplaces and their chimneys shall be
constructed of concrete or solid masonry not less than 12"
thick, and extend 6-inches beyond the face of the
fireplace or foundation wall on all sides. Footings shall
be founded on natural, undisturbed earth or engineered
fill below the frost depth, at least 12” below finished
grade. Masonry or concrete chimneys shall be anchored at
each floor, ceiling, or roof line more than 6-ft. above
grade, except where completely within the exterior walls.
Unless designed otherwise masonry and concrete
chimneys shall be reinforced and anchored in accordance
to Chapter 1001.
Columns shall be restrained to prevent lateral
displacement at the bottom end. Wood columns shall not
be less in nominal size than 4” x 4” or approved
equivalent.
54. GIRDERS ENTERING MASONRY OR CONCRETE
WALLS: IRC Section R317.1 #4. The ends of wood
girders entering exterior concrete or masonry walls shall
be provided with a 1/2" airspace on tops, sides and ends
unless an approved species and grade of lumber specified
in Sections R317.1 & R317.2 and listed in #56 of this
checklist is used.
51. UNDER-FLOOR VENTILATION: WAC amendment
to IRC Section R408.1 and R408.2. The under-floor
space between the bottom of the floor joists and the earth
under any building (except space occupied by a basement
or cellar) shall be provided with ventilation openings
through foundation walls or exterior walls having a net
area of not less than 1 square foot for each 300 square
feet of under-floor space area. In addition, a ground
cover shall be installed in accordance to item #96. One
55. POST-BEAM CONNECTIONS/FASTENING: IRC
Section R502.9, R301. Where post and beam or girder
construction is used to support floor framing, positive
11
connections shall be provided to ensure against uplift and
lateral displacement. The construction of buildings and
structures shall result in a system that provides a complete
load path that meets all requirements for the transfer of all
loads from their point of origin through their load
resisting elements to the foundation.
ASTM B 695, Class 55, minimum. Sill plate need not be
pressure treated if sill plate installed over an approved
moisture barrier such as 30 lb. Felt or equivalent and the
sill plate is 8” or more above grade.
57. FLOOR FRAMING: IRC Chapter 5, Section R502.6,
R502.7, R501.3. The ends of each joist, beam or girder
shall have not less than 1- ½” bearing on wood or metal
and not less than 3” on masonry or concrete except where
supported on a 1” x 4” ribbon strip and nailed to the
adjacent stud or by the use of approved joist hangers.
Joist framing from opposite sides of a beam or partition
shall lap a minimum of 3” and shall be nailed together
with three 10d-face nails. A wood splice with strength
equal to or greater than that provided by the nailed lap is
permitted. Joists framing into the side of a wood girder
shall be supported by approved framing anchors or on
ledger strips not less than 2-inches x 2-inches. Joists shall
be supported laterally at the ends and at each intermediate
support by full depth solid blocking not less than 2”
nominal thickness; or by attachment to a full-depth
header, band or rim joist, or to an adjoining stud; or shall
be otherwise provided with lateral support to prevent
rotation. Joists exceeding a nominal 2” x 12” shall be
supported laterally by solid blocking, diagonal bridging
(wood or metal), or a continuous 1” x 3” strip nailed
across the bottom of joists perpendicular to joists at
intervals not exceeding 8’0”. See Figure R502.2 for floor
framing information and Tables 502.3.1(1), R502.3.1(2),
R502.3.3(1) and R502.3.3(2) for allowable spans.
Structural floor members shall not be cut, bored or
notched in excess of that Section R502.8. Notches in
solid lumber joists, rafters and beams shall not exceed 1/6
of the depth of the member, shall not be longer than 1/3
of the depth of the member and shall not be located in the
middle 1/3 of the span. Notches at the ends of the
member shall not exceed 1/4 the depth of the member.
The tension side of members 4 inches or greater in
nominal thickness shall not be notched except at the ends
of the members. The diameter of holes bored or cut into
members shall not exceed 1/3 the depth of the member.
Holes shall not be closer than 2 inches to the top or
bottom of the member, or to any other hole located in the
member. Where the member is also notched, the hole
shall not be closer than 2 inches to the notch.
Engineered wood products. Cuts, notches and holes
bored in trusses, structural composite lumber, structural
glue-laminated members or I-joists are prohibited except
where permitted by the manufacturer’s recommendations
or where the effects of such alterations are specifically
considered in the design of the member by a registered
design professional. Floor framing shall be Fastened in
accordance with Table R602.3(1). Posts and beams used
to support floor framing shall be provided with positive
connections to ensure against uplift and lateral
displacement. Floor assemblies, where the space
below is used for storage or fuel-fired appliances shall
be protected from fire in accordance with R501.3.
Exception: dimensional or stuctural composite wood
56. MINIMUM STANDARDS & PROTECTION
AGAINST DECAY: IRC Sections R317.1, R317.2, &
R317.3, R502.1, R602.1, R802.1. In areas subject to
decay and where required, the use of an naturally durable
wood and grade of lumber shall be required, including
wood pressure treated in accordance with AWPA U1,
listed in Section 4, or naturally durable wood such as
decay resistant redwood, black locust, black walnut or
cedar. Pressure-preservative-treated wood shall bear the
quality mark of an approved agency in accordance to
R317.2. Field cut ends, notches and drilled holes of
preservative-treated wood shall be treated in the field in
accordance to AWPA M4. All wood embedded in
concrete exposed to weather that supports permanent
structures intended for human occupancy shall be
approved pressure-preservative-treated wood suitable for
ground contact use, except untreated wood may be used
entirely below groundwater level or continuously
submerged in fresh water. Approved naturally durable or
pressure-preservative-treated wood shall be used for those
portions of wood members that form the structural
supports of buildings, balconies, porches or similar
permanent building appurtenances when they are exposed
to weather without adequate protection from a roof, eave,
overhang or other covering that would prevent moisture
or water accumulation on the surface or at joins between
members. Load bearing dimension lumber used for joists,
beams, girders, studs, plates, headers, rafters, trusses, and
ceiling joists, including, end-jointed lumber, prefabricated I-joists, structural glue-laminated timber,
structural log members, wood structural panels,
fiberboard sheathing (when used structurally), hardboard
siding (when used structurally), particleboard,
preservative treated wood, fire-retardant-treated wood,
hardwood plywood, shall be identified by a grade mark
of a lumber grading or inspection agency that has been
approved by an accreditation body that complies with
DOC PS 20. In lieu of a grade mark, a certificate of
inspection issued by a lumber grading or inspection
agency meeting the same requirements shall be accepted.
FASTENERS: Fasteners for pressure preservative and
fasteners for pressure-preservative and fire-retardanttreated wood shall be of hot-dipped zinc-coated
galvanized steel, stainless steel, silicon bronze or copper.
The coating weights for zinc-coated fasteners shall be in
accordance with manufacturer recommendations or in
accordance to ASTM A 653 type G185. See also
manufacturer specifications or distributor specific
installation instructions or recommendations. Exception:
1) ½” diameter or larger steel bolts (where required by
location). 2) Fasteners other than nails and timber rivets
shall be permitted to be mechanically deposited zinccoated steel with coating weights in accordance with
12
intersections with bearing partitions. End joints in top
plates shall be offset at least 24”. Joints in plates need not
occur over studs. Plates shall be a nominal 2” in depth
and have a width at least equal to the width of studs.
Where joists, trusses, or rafters are spaced more than 16”
o.c. and the bearing studs are spaced 24” o.c. such
members shall bear within 5” of the studs beneath. Studs
shall have full bearing on a 2-inch nominal or larger plate
or sill having a width at least equal to the width of the
studs.
Drilling & notching – studs (R602.6): Notching: Any
stud in an exterior wall or bearing partition may be cut or
notched to a depth not exceeding 25% of the stud width.
Studs in non-bearing partitions maybe notched to a depth
not to exceed 40% of a single stud width. Drilling: Any
stud may be bored or drilled, provided that the diameter
of the resulting hole is not more than 60% of the stud
width, the edge of the hole is no closer than 5/8” to the
edge of the stud, and the hole is not located in the same
section as a cut or notch. Studs located in exterior walls
or bearing partitions drilled over 40% and up to 60% shall
be doubled with no more than 2-successive doubled studs
bored (See Figure R602.6.(1) and R602.6(2). Exception:
Use of approved stud shoes is permitted when they are
installed in accordance with the manufacturer’s
recommendations. and R602.6 for additional details.
Drilling and notching of top plate: When piping or
ductwork is placed in or partly in an exterior wall or
interior load bearing wall, necessitating cutting, drilling
or notching of the top plate by more than 50% of its
width, a galvanized metal tie of not less than .054-inch
thick and 1½ inches wide shall be fastened across the
plate at each side of the opening with not less than 8-10d
nails at each side having a min. length of 1½” each side or
equivalent. The metal tie must extend a min. of 6” past
the opening. (See figure R602.6.1). Foundation cripple
walls (WAC R602.9) shall be framed of studs not less in
size than the studding above. When exceeding 4’0” in
height, such walls shall be framed of studs having the size
required for an additional story. Cripple walls with a stud
height less than 14” shall be sheathed on at least one side
with a wood structural panel that is fastened to both the
top and bottom plates in accordance with Table R602.3(1)
or the cripple walls shall be constructed of solid blocking.
Cripple walls shall be supported on continuous
foundations. Exception: Footings supporting cripple
walls used to support interior braced wall panels as
required in Sections R403.1.2 and R602.10.7.1 shall be
continuous for the required cripple wall and constructed
beyond the cripple wall for a min. distance of 4” and a
maximum distance of the footing thickness. The footings
extension is not required at intersections with other
footings.
floor assemblies with a cross-sectional area equal to
2x10 or equivalent.
58. JOISTS UNDER BEARING PARTITIONS: IRC
Section R502.4. Joists under parallel bearing partitions
shall be of adequate size to support the load. Double
joists, sized to adequately support the load, that are
separated to permit the installation of piping or vents shall
be full depth solid blocked with lumber not less than 2” in
nominal thickness spaced not more than 4’ o.c. Bearing
partitions perpendicular to joists shall not be offset from
supporting girders, walls or partitions more than the joist
depth unless joists are of sufficient size to carry the
additional load.
59. UNDER-FLOOR CLEARANCE / REMOVAL OF
DEBRIS: IRC Section R317.1 #1, R408.5. When floor
joists or the bottom of a wood structural floor are located
within 18" or wood girders are located within 12" to the
exposed ground in crawl spaces or unexcavated area
located within the periphery of the building foundation,
all components of the floor assembly shall be wood
approved in areas subject to decay as identified in #56 of
this checklist. Included are the posts, beams or girders,
joists and sub-floor. The under-floor grade shall be
cleaned of all vegetation and organic material. All wood
forms used for placing concrete and construction
materials shall be removed before the building is
occupied or used for any purpose.
60. UNDER-FLOOR ACCESS: IRC Section R408.4,
M1305.1.4. Access shall be provided to all under-floor
spaces. Access openings through the floor shall be a
minimum of 18" x 24". Openings through a perimeter
wall shall be at least 16” x 24”. When any portion of the
through wall access is below grade, an areaway not less
than 16” x 24” shall be provided. The bottom of the
areaway shall be below the threshold of the access
opening. Through wall access openings shall not be
located under a door to the residence. Where appliances
are located under floors a rough-framed access shall be
provided with an opening or door and an unobstructed
passageway not less than 22 inches wide and large
enough to allow the removal of the largest appliance in
the space. Access shall be unobstructed by pipes, ducts
or similar construction.
61. WALL FRAMING: IRC Section R602 including
R602.3.1, R602.3.2, R602.3.3, R 602.3.4, R602.6 &
R602.9. The size, height, and spacing of all other woodframing studs shall be in accordance with Table
R602.3(5). Exception: 1) Utility grade studs shall not be
spaced more than 16" on center, support more than a
roof and ceiling, and shall not exceed 8-feet in height for
exterior and load bearing walls or 10' for interior nonbearing walls. 2)Studs greater than 10’ in height that are
in accordance with Table R602.3.1. Studs shall be
placed with their wide dimension perpendicular to the
wall. Wood stud walls shall be capped with a double top
plate installed to provide overlapping at corners and
62. WALL BRACING: IRC 602.10. Mason County is
located in Seismic Design Category (SDC) D2. All
braced walls and cripple wall bracing in Seismic Design
Category D2 shall be constructed in accordance with IRC
Tables R602.10.1.3(1) & (3) and Sections R602.10 and
R602.11. Standard braced wall panels require nailing
13
.
patterns of 6” o.c. along all panel edges. All sheathing
joints must be over studs (vertically) or solid block at
joints (horizontally).

Braced wall panels shall begin no more than 10’ 0”
from each end of a braced wall line and be no more
than 20-ft apart. If the braced wall panel is not
located at the corner, a 24” panel shall be required
at the corner return panel, in addition to the
required BWP within 10’. As an option an 1800#
hold down device shall be installed at the end of the
braced wall panel nearest the corner.

Spacing of interior braced wall lines shall not
exceed 25’ apart. An increase up to 35’ apart for
one room upto 900 sq. ft., is permitted provided the
braced wall length is adjusted in accordance with
IRC Table R602.10.3(4). (Ref Table R602.10.1.3)

Braced wall lines may have offsets, out of plane of
up to 4’0”.

In one-story buildings, braced wall panels shall be
supported on continuous foundations at intervals
not exceeding 50’. In two- story buildings all
interior braced wall panels shall be supported on
continuous foundations. See also #45 for exceptions
to IRC R602.10.9.1.

Interior braced wall panels shall be fastened to both
the floor and roof framing in accordance with Table
R602.10.8(1) & (2) . See details.

Cripple walls supporting bearing walls or exterior
walls or interior braced wall panels as required in
IRC R403.1.2 shall be braced in accordance with
Tables R602.10.3(3) & (4). Cripple wall greater than
4’ shall be designated as the first story wall for
purposes of designating the wall bracing requirements
(R602.10.7.1).

Where “stepped foundations” occur, See IRC
R602.10.11.2 for additional requirements such as plate
strapping, cripple wall height limitations, etc.
 See also attached “Braced Wall Panel” and “Alternate
Braced Wall Panel” details for typical construction
requirements.
Adhesive attachment is not permitted.
64. FIREBLOCKING & DRAFTSTOPPING: IRC
R302.11, R302.12, R1001.12, R1003.19.
FIREBLOCKING shall be installed to cut off all
concealed vertical and horizontal draft openings and shall
form an effective fire barrier between stories and between
a top story and the roof space. Fireblocking shall be
provided in wood-frame construction in the following
locations: 1) In concealed spaces of stud walls and
partitions, including furred spaces and parallel rows of
studs or staggered studs as follows: a) Vertically at the
ceiling and floor levels. b) Horizontally at intervals not
exceeding 10 feet 2) 2) At all interconnections between
concealed vertical and horizontal spaces such as occur at
soffits, drop ceilings and cove ceilings. 3) In concealed
spaces at stair stringers at the top and bottom of the run.
Enclosed spaces under stairs shall comply with Section
R302.7. 4) At openings around vents, pipes and ducts,
cables and wires at ceiling and floor level, with an
approved material to resist the free passage of flame and
products of combustion. 5) For the fireblocking of
chimneys and fireplaces, see Section R1003.19. 6)
Fireblocking of cornices of a two-family dwelling is
required at the line of dwelling unit separation. Fire
blocking materials shall consist of material listed in
Section R302.11.1. Loose-fill insulation material shall
not be used as a fireblock unless specifically tested in the
form and manner intended. The integrity of all fireblocks
shall be maintained. DRAFTSTOPPING: Where there is
usable space both above and below a concealed space of a
floor/ceiling assembly, draftstops shall be installed so that
the area of the concealed space does not exceed 1000
square feet. Draftstops shall divide the concealed space
into approximately equal areas. Draftstopping materials
shall consist of the following materials: ½” gypsum
board, 3/8” wood structural panels, or other approved
materials adequately supported. Draftstopping shall be
installed parallel to the floor framing members unless
otherwise approved. The integrity of draftstops shall be
maintained. CHIMNEY FIREBLOCKING: All spaces
between chimneys and floors and ceilings through which
chimneys pass shall be fireblocked with noncombustible
material securely fastened in place. The fireblocking of
spaces between chimneys and wood joists, beams, or
headers shall be self-supporting or be placed on strips of
metal or metal lath laid across the spaces between
combustible material and the chimney.
63. OPENINGS IN EXTERIOR & INTERIOR WALLS
(HEADERS): IRC Section R602.7, R502.5 & R502.6.
Headers shall be provided over each opening in exteriorbearing walls. Headers shall be of two pieces of nominal
2-inch framing lumber set on edge as permitted in tables
R502.5 (1) and R502.5 (2) and nailed together in
accordance with Table R602.3(1) or of solid lumber of
equivalent size. Exterior headers not listed in the tables
shall be designed to support the loads specified in Table
R301.5. Each end of all headers shall have at least 1-1/2"
of bearing for the full width. A single flat 2”x4” member
be used as header in interior or exterior nonbearing walls
for openings up to 8-ft in width if the vertical distance to
the parallel nailing surface above is not more than 24inches.
65. EXTERIOR COVERING & ATTACHMENTS: IRC
Section R701.2, 703.1, R703.4, R703.5, R703.6, R703.7,
R703.8, R703.9, R703.10, R703.11. Exterior walls shall
provide the building with a weather- resistant exterior
wall envelope. The exterior wall envelope shall include
flashing as described in Section R703.8. The exterior
wall envelope shall be designed and constructed in a
manner that prevents accumulation of water within the
wall assembly by providing a water resistant barrier
behind the exterior veneer, as specified in item #66,
R703.2, and a means draining water that enters the
assembly to the exterior. Protection against condensation
in the exterior wall assembly shall be provided in
14
accordance with section R601.3 of this code and the
Washington State Energy Code (WSEC) as described in
item #95. Ensure proper fastening for type used, wood
siding may not be less than 3/8" thick. See Table R703.4.
Approved corrosion-resistant fasteners shall be provided
in the exterior wall envelope in such a manner as to
prevent entry of water into the wall cavity or penetration
of water to the building structural framing components.
See #67 for information related to masonry and anchored
stone wall coverings.
wood frame located in Seismic Design Category D-0 and
D-1, exterior stone or masonry veneer, as specified in
Table R703.7(2) above a noncombustible foundation.
Wall bracing and holdowns at exterior and interior braced
wall lines shall be in accordance with section R602.10
and R602.11 and the additional requirements of Table
R703.7(2). Cripple walls shall not be permitted, and
required interior braced wall lines shall be supported on
continuous foundations.
Anchored veneer shall be supported on footings,
foundations or other noncombustible support. Wall ties
shall be corrosion resistant.
66. WEATHER RESISTANT SHEATHING PAPER and
FLASHING: IRC Section R703.2 and R703.8.One layer
of #15 asphalt felt, free from holes and breaks, complying
with ASTM D 226 for Type I felt or other approved
water-resistant material shall be applied over studs or
sheathing of all exterior walls. Such felt or material shall
be applied horizontally, with the upper layer lapped over
the lower layer not less than 2”. Where joints occur felt
shall be lapped not less than 6-inches. The felt or other
approved material shall be continuous to the top of walls
and terminated at penetrations and building appendages in
a manner to meet the requirements of the exterior
envelope as described in item #65, R703.1. Exceptions:
Omission of the water-resistant barrier is permitted in the
following situations: 1) in detached accessory buildings.
2) Under exterior wall finish materials as permitted in
Table R703.4. 3 or 3) Under paperbacked stucco lath
when the paper backing is an approved weather-resistive
sheathing paper.
68. SIDING/EARTH SEPARATION: IRC Section R317.1
- #5. Wood siding, sheathing and wall framing on the
exterior of the building used within 6" of earth shall be
natural durable wood or wood that is preservative treated
in accordance that specified in item #56 of this checklist.
Wood or other products shall conform to the most
restrictive of either manufacturer specifications or code
requirements.
69. DECKS & EXTERIOR STAIRS: IRC R507. All
wood in contact with the ground, embedded in concrete in
direct contact with the ground or embedded in concrete
exposed to the weather that supports permanent structures
intended for human occupancy shall be naturally durable
wood as specified in item #56 or approved pressurepreservative-treated wood suitable for ground contact use.
In addition naturally durable wood or pressure
preservative treated wood shall be used in those portions
of wood members that form the structural supports of
buildings, balconies, porches or similar permanent
building appurtenances when those members are exposed
to the weather without adequate protection from a roof,
eave, overhang or other covering that would prevent
moisture or water accumulation on the surface or at joints
between members. Such members may include: 1)
Horizontal members such as girders, joists and decking.
2) Vertical members such as posts, poles and columns. 3)
Both horizontal and vertical members. Field applied
treatment is not an approved method. Treatment must be
applied by manufacturer, see item #56 of this checklist.
Where supported by attachment to an exterior wall, decks
shall be positively anchored to the primary structure and
designed for both vertical and lateral loads as applicable.
Such attachment shall not be accomplished by the use of
toenails or nails subject to withdrawal. Where positive
connection to the primary building structure cannot be
verified during inspection, decks shall be self-supporting.
Decks connected to the structure shall be provided with
an approved deck ledger connected with hot-dipped
galvanized or stainless steel lag screws, bolts, and
washers in accordance with the detail attached, “Deck
Ledger Attachment Details and Specifications.” Girders
supporting deck joists shall not be supported on deck
ledgers or band joists.
FLASHING: Approved corrosion resistant flashing shall
be applied shingle-fashion in such a manner to prevent
entry of water into the building cavity or penetration of
water to the building structural framing components.
Self-adhered membranes used as flashing shall comply
with AAMA 711. The flashing shall extend to the surface
of the exterior wall finish. Approved corrosion resistant
flashing shall be installed at all of the following locations:
1) Exterior window and door openings. Flashing shall
extend to the surface of the exterior wall finish or to the
water-resistive barrier for subsequent drainage. 2) At the
intersection of chimneys or other masonry construction
with frame or stucco walls, with projecting lips on both
sides under stucco copings. 3) Under and at the ends of
masonry, wood or metal copings and sills. 4)
Continuously above all projecting wood trim. 5) Where
exterior porches, decks or stairs attach to a wall or floor
assembly of wood construction. 6) At wall and roof
intersections. 7) At built-in gutters.
67. STONE AND MASONRY VENEER, GENERAL:
IRC Section R703.7. All stone and masonry veneer shall
be installed in accordance with IRC Chapter 7, Table
R703.4 and Figure R703.7. Such veneers installed over
backing of wood or cold-formed steel shall be limited to
the first story above grade and shall not exceed 5” in
thickness. Exception: 2. For detached one- or two- family
dwellings with a maximum nominal thickness of 4 inches
(102 mm)of exterior masonry veneer with a backing of
Deck lateral load connections shall be provided in
accordance with R507.2.3. Decks more than 30-inches
15
above grade, shall be provided with hold-down tension
devices, or be self-supporting. Hold-down devices shall
be installed in accordance with manufacturer
specifications, in not less than two (2) locations per deck.
As an option, where a deck is being added to an
existing structure, 750# capacity hold down devices
may be installed at 4 locations, evenly distributed,
within 2-ft of each end of the ledger and shall fully
engage the deck joist. See IRC Figure R507.2.3(2),
“Deck attachment for lateral loads.”
72. RAFTER OPENINGS: IRC Section R802.9. Openings
in roof and ceiling framing shall be framed with header
and trimmer joists. When the header joist does not
exceed 4’, the header joist may be a single member the
same size as the ceiling joist or rafter. Single trimmer
joists may be used to carry a single header joist that is
located within 3’ of the trimmer joist bearing. When the
header joist span exceeds 4’, the trimmer joists and the
header joist shall be doubled and sufficient cross section
to support the ceiling joists or rafter framing into the
header. Approved hangers shall be used for the header
joist to trimmer joist connections when the header joist
span exceeds 6-ft. Tail joists over 12-ft long shall be
supported at the header by framing anchors or on ledger
strips not less than 2"x2."
70. WOOD TRUSSES: IRC Section R502.11, R602.10.6.2,
R802.10. Wood trusses shall be designed in accordance
with approved engineering practice. Engineering data
and installation specifications, including the type of
roofing to be used, shall be available on site at framing
inspection. Roof trusses shall be supported laterally at
points of bearing by solid blocking to prevent rotation
and lateral displacement.
73. CEILING JOISTS LATERAL SUPPORT
/BRIDGING: IRC Section R802.8, R802.8.1. Rafters
and ceiling joists having a depth-to-thickness ratio
exceeding 5 to 1 based upon nominal dimensions shall be
provided with lateral support at points of bearing to
prevent rotation. Rafters and ceiling joists having a
depth-to-thickness ratio exceeding 6 to 1 based upon
nominal dimensions shall be supported laterally by solid
blocking, diagonal bridging (wood or metal) or
continuous 1” x 3” wood strip nailed across the rafter or
ceiling joists at intervals not exceeding 8’.
71. RAFTERS: IRC Sections R802.3, R802.8. Rafters shall
be framed to ridge board or to each other with a gusset
plate as a tie. Ridge board shall be at least 1-inch
nominal thickness and not less than the cut end of the
rafter. At all valleys or hips there shall be a valley or hip
rafter not less than 2" nominal thickness and not less in
depth than the cut end of the rafter. Hip and valley rafters
shall be supported at the ridge by a brace to a bearing
partition or be designed to carry and distribute the
specific load at that point. Where the roof pitch is less
than three units in 12 unit horizontal (25-percent slope),
structural members that support rafters and ceiling joists,
such as ridge beams, hips and valleys, shall be designed
as beams. Ceiling joists and rafters shall be nailed to each
other in accordance with Tables R802.5.1(9), and the
rafter shall be nailed to the top wall plate in accordance
with Table R602.3(1). Ceiling joists shall be continuous
or securely joined in accordance with Table R802.5.1(9)
where they meet over interior partitions and nailed to
adjacent rafters to provide a continuous tie across the
building when such joists are parallel to the rafters.
Where ceiling joists are not connected to the rafters at the
top wall plate, joists connected higher in the attic shall be
installed as rafter ties, or rafter ties shall be installed to
provide a continuous tie. Where ceiling joists are not
parallel to the rafters, rafter ties shall be installed. Rafter
ties shall be min. 2”x4”, installed in accordance with
connection requirements in Table R802.5.1(9), or
connections of equivalent capacities shall be provided,
the ridge formed by these rafters shall be supported by a
wall or girder designed in accordance with engineering
practice. Collar ties or ridge straps to resist wind uplift
shall be connected in the upper third of the attic space in
accordance with Table R602.3.1. Collar ties shall be
minimum of 1”x4” spaced not more than 4-ft o.c. Rafters
and ceiling joists having a depth-to-thickness ratio
exceeding 5 to 1 based on nominal dimensions shall be
provided with lateral support at points of bearing to
prevent rotation.
74. ROOF DRAINAGE: UPC 1101.11.1. Roof areas of a
building shall be drained by roof drains or gutters.
Gutters and downspouts to be installed on structures to
conform with the provisions of Mason County Code, title
14 chapter 14.48 (Stormwater Management), and IRC
R401.3. If a stormwater plan is not required, or an
alternative method is proposed, measures must be put in
place to protect the structure from excessive splash, divert
the water away from the foundation per IRC R401.3,
R405 & R405.1, and protect the parcel (and adjacent
parcels) from erosion. IRC Section R903.4. Unless
roofs are sloped to drain over roof edges, roof drains shall
be installed at each low point of the roof. Where required
for roof drainage, scuppers shall be placed level with the
roof surface in a wall or parapet. Overflow drains shall
discharge to an approved location and shall not be
connected to roof drain lines.
75. ROOF MATERIALS: IRC Section R904 & R905. Roof
covering materials shall be delivered in packages bearing
the manufacturer’s identifying marks and approved
testing agency labels when required. Roof coverings shall
be applied and installed in accordance with Section R905
and the manufacturer’s installation instructions. Asphalt
shingles classified using ASTM D 3161 are acceptable
for use in Mason County and other areas where wind
zones less than 110 mph .
76. ATTIC VENTILATION: IRC Section R806. Enclosed
attics and rafter spaces formed where ceilings are applied
directly to the underside of roof rafters shall have cross
ventilation for each separate space by ventilating
16
allows warranty to be maintained by the roofing
manufacturer.
openings protected against the entrance of rain and snow.
Ventilating openings shall be provided with corrosionresistant wire mesh, with 1/16” minimum and ¼”
maximum openings. The total net free ventilating area
shall not be less than 1 to150 of the area of the space
ventilated, except that the total area is permitted to be
reduced to 1 to 300, provided at least 50% and not more
than 80% of the required ventilating area is provided by
ventilators located in the upper portion of the space to be
ventilated at least 3’ above eave or cornice vents with the
balance of the required ventilation provided by eave or
cornice vents. As an alternative, the net free crossventilation area may be reduced to 1 to 300 when a Class
I or II vapor barrier is installed on the warm-in-winter
side of the ceiling. Where eave or cornice vents are
installed, insulation shall not block the free flow of air. A
minimum of a 1” space shall be provided between the
insulation and the roof sheathing at the location of the
vent. Unvented attic assemblies may be permitted
provided all the conditions of Washington State
Amendment R806.4 are met AND such installation
77. CHIMNEY HEIGHT/CHIMNEY CRICKETS: IRC,
R1003.9, R1003.20 R1005, R905.2.8.3. Masonry
chimneys shall extend at least 2-ft higher than any portion
of a building within 10-ft, but shall not be less than 3-ft.
above the highest point where the chimney passes
through the roof. Masonry chimneys shall be provided
with crickets when the dimension parallel to the ridgeline
is greater than 30” and does not intersect the ridgeline.
The cricket and chimney shall be flashed and counter
flashed and shall be constructed in compliance with
Figure R1003.20 and Table R1003.20. Factory-built
chimneys shall be listed and labeled and shall be installed
and terminated in accordance with the manufacturer’s
installation instructions. A cricket or saddle shall be
installed on the ridge side of any chimney or penetration
of roof more than 30-inches wide as measured
perpendicular to the slope. Cricket or saddle coverings
shall be sheet metal or of the same material as the roof
covering.
GENERAL
unit shall be provided with heating facilities capable of
maintaining a minimum room temperature of 680 F at a
point 3' above the floor and 2’ from exterior walls in all
habitable rooms at the design temperature. The
installation of portable heaters shall not be used to
achieve compliance with this section. Primary heating
sources in all new and substantially remodeled buildings
shall not be dependent upon wood stoves. No used solid
fuel-burning device shall be installed in new or existing
buildings unless such device is U.S. EPA certified or a
pellet stove either certified or exempt from certification
by the U.S. EPA. Exception: Antique wood cook stoves
and heaters manufactured prior to 1940.
78. PREMISE IDENTIFICATION: IRC Section R319,
IFC Section 505, and Mason County Code Title 14.28.
(see also checklist item 110). Approved numbers or
addresses shall be a minimum of 4” high with a stroke of
½” and shall be provided for all new buildings in such a
position as to be plainly visible and legible from the street
or road fronting the property and shall be a minimum of
4” high with a minimum width of ½”. Approved numbers
or addresses shall be placed on all buildings, at the
beginning of long driveways when the address is not
clearly visible from the access road, or in any other areas
deemed necessary by the local fire district or Fire
Marshal. They shall be placed in such a position as to be
plainly visible and legible from the street or road fronting
the property. Said numbers shall contrast with their
background. See address posting and private road signage
requirement information attached.
81. SKYLIGHTS: IRC Section R308.6.2. The following
types of glazing may be used: 1) Laminated glass with a
minimum .015” polyvinyl butyl interlayer for glass panes
16 sq. ft. or less in area located such that the highest point
of the glass is not more than 12’ above a walking surface
or other accessible area; for higher or larger sizes, the
minimum interlayer thickness shall be .030”. 2) Fully
tempered glass. 3) Heat-strengthened glass. 4) Wired
glass. 5) Approved rigid plastics. Installed skylights
shall comply with Washington State Energy Code
requirements.
79. APPROVED PLANS: IRC Sections R106.3.1, R106.4.
When the building official issues a permit, the
construction documents shall be approved in writing or
by stamp. One set of the construction documents so
reviewed shall be retained by the building official. The
other set shall be returned to the applicant, shall be kept at
the site of work and shall be open to inspection by the
building official or the duly authorized representative.
The work shall be installed in accordance with the
approved construction documents, and any changes made
during construction that are not in compliance with the
approved construction documents shall be resubmitted for
approval as an amended set of construction documents.
82. INTERIOR FINISHES: IRC Sections R302.9, R316
and R702.5 Wood veneer paneling and hardboard
paneling shall be placed on wood or cold-formed steel
framing spaced not more than 16-inches o.c. Wood
veneer and hardboard paneling less than ¼” nominal
thickness shall have not less than 3/8-inch gypsum board
backer. Wood veneer paneling not less than ¼” nominal
thickness shall conform to ANSI/HPVA HP.1.
80. HEATING: IRC Section R303.9 & Washington State
Amendment to R303.9.2 andR303.9.2. Every dwelling
17
Hardboard paneling shall conform to ANSI/AHA
A135.5. All structural panel components within the
conditioned space such as plywood, particleboard, wafer
board and oriented strand board shall be identified as
“EXPOSURE 1,” “EXTERIOR” or “HUDAPPROVED.” When using foam plastic insulation the
interior of the building shall be separated by a thermal
barrier of at least ½” gypsum wallboard. The ½” gypsum
wallboard is not required when the foam plastic in a roof
assembly or under a roof covering is installed in
accordance with the manufacturer’s installation
instructions and is separated from the interior of the
building by tongue-and-groove wood planks not less than
15/32 inch (11.9 mm) thick bonded with exterior glue and
identified as Exposure 1, with edges supported by
blocking or tongue-and-groove joints. The smokedeveloped index for roof applications shall be maintained.
ceiling framing and shall be fastened at 6” o.c. by
minimum 1-7/8” 6d coated nails or equivalent drywall
screws.
 3/8" minimum from edge and ends for nails or
screws.
 Fastening (nails): 7" o.c. max. ceiling, 8" walls.
 Fastening (screws): 12" o.c. ceiling, 16" o.c. walls
when wall framing is 16" o.c., 12" when wall
framing is 24" o.c.
84. STORY/STORY ABOVE GRADE: IRC Section R202.
Any story having it’s finished floor surface entirely above
grade plane, except that a basement shall be considered as
a story above grade plane where the finished surface of
the floor above the basement meets any of the following:
1)Is more than 6’ above grade plane. 2) Is more than 6’
above the finished ground level for more than 50% of the
total building perimeter. 3) Is more than 12’ above the
finished ground level at any point.
83. GYPSUM WALLBOARD & GYPSUM
WALLBOARD FASTENING: IRC Section R702.3,
and Table R702.3.5..All wood framing supporting
gypsum board shall not be less than 2-inches nominal
thickness in the least dimension except that furring strips,
not less than 1”x 2” may be used over solid backing or
framing spaced not more than 24-inches o.c. When
gypsum is used as a base or backer for adhesive
application of ceramic tile or other required nonabsorbent
material shall conform with ASTM 1396, or C1278. Use
of water resistant gypsum backing board shall be
permitted to be used on ceilings where framing spacing
does not exceed 12” o.c. for ½” thick or 16” o.c. for 5/8”
thick gypsum board. Water resistant gypsum wallboard
shall not be installed over a class I or II vapor retarder, in
a shower or tub compartment. Cut or exposed edges,
including those at wall intersections, shall be sealed as
recommended by the manufacturer. Limitations: Waterresistant gypsum backing board shall not be used where
there will be direct exposure to water, or in areas subject
to continous high humidity. Screws for attaching gypsum
board to wood framing shall be type W or Type S in
accordance with ASTM C 1002 and shall penetrate the
wood not less than 5/8”. Footnote e, Table R702.3.5:
Type X gypsum wallboard for garage ceilings beneath
habitable rooms shall be installed perpendicular to the
85. HEIGHT OF BUILDING/GRADE PLANE: IRC
Section R202. The vertical distance from grade plane to
the average height of the highest roof surface. The grade
plane : A reference plane representing the average of the
finished ground level adjoining the building at all exterior
walls. Where the finished ground level slopes away from
the exterior walls, the reference plane shall be established
by the lowest points within the area between the building
and the lot line or, where the lot line is more than 6’ from
the building between the structure and a point 6’ from the
building..
86. RETAINING WALLS: IRC Section R105.2, R404.4.
Retaining walls that are not laterally supported at the top
and that retain in excess of 24-inches of unbalanced
backfill shall be designed to ensure stability against
overturning, sliding, excessive foundation pressure and
water uplift. Retaining walls shall be designed for a
safety factor of 1.5 against lateral sliding and overturning.
Retaining walls that are not over 4’ in height measured
from the bottom of the footing to the top of the wall not
supporting a surcharge is exempt from permits.
ENERGY CODE/VENTILATION (IECC/WSEC & IRC CHAPTER 15
MASON COUNTY CLIMAT ZONE: 4C (MARINE)
protected. For monolithic slabs, the insulation shall
extend downward from the top of the slab to the bottom
of the footing. Unless approved for other than
prescriptive approach the typical R-Value for slab
insulation shall be R-10. Insulation used for this
application shall be rated for such use. The entire area
of a radiant slab shall be thermally isolated from the
soil with min. R-10 insulation approved bt the listing for
it’s intended use.
87. FOUNDATION INSULATION: IECC/WSEC R303,
R402.2.8, R402.2.9, Table R402.1.1. Slab-on-grade
insulation, installed inside the foundation wall, shall
extend downward from the top of the slab for a
minimum distance of 24" or downward and then
horizontally beneath the slab for a minimum combined
distance of 24". Insulation installed outside the
foundation shall extend downward to a minimum of 24"
or to the frostline. Above grade insulation shall be
18
91. VAULTED CEILING INSULATION: R402.2 Tables
R402.1.1 and R402.4.1.1.Vaulted ceiling insulation shall
be installed where an enclosed joist or rafter space is
formed by ceilings applied directly to the underside of
roof joists or rafters. This requirement applies where
both the distance between the top of the ceiling and the
underside of the roof sheathing is less than 12-inches
and there is a minimum 1-inch vented air space above
the insulation. Where a single rafter or joist-vaulted
ceiling is 13-inches or more the space shall be insulated
as a ceiling, typically R-38, described in item #90 of this
checklist. Vaulted ceilings shall be insulated to not less
than the nominal R-value specified on the approved
building plans. Unless approved for other than
prescriptive approach the typical R-Value for nontrussed, vaulted ceiling insulation shall be R-38, see also
#90. Faced batts shall be face-stapled (not insetstapled).
88. UNDER-FLOOR INSULATION: . IECC/WSEC
R303, R402.2.7. Table R402.1.1 & Table R402.4.1.1.
Floor insulation shall be installed in a permanent manner
in substantial contact with the surface being insulated
and shall include areas over unconditioned spaces, such
as vented crawl spaces, unheated basements and garages.
The nominal R-value shall not be less than that approved
for floors over unconditioned spaces on the approved
building plan. Unless approved for other than
prescriptive approach the typical R-Value for floors shall
be R-30. Insulation shall be installed in substantial
contact with the sub-floor and supported not less
than 24” o.c. Foundation vents shall be placed so that
the top of the vent is below the lower surface of the floor
insulation
89. WALL INSULATION: IECC/WSEC R303, R402.2.8
& Table R402.1.1, Table R402.4.1.1. Above grade
exterior walls shall be insulated to not less than the
nominal R-value specified on the approved building
plans. Unless approved for other than prescriptive
approach the typical R-Value for wall insulation shall be
R-21. All exterior wall insulation shall fill the entire
framed cavity. Faced batts shall be face-stapled to avoid
compression (not inset-stapled).
92. ACCESS HATCHES AND DOORS: R402.2.4.
Access doors from conditioned to unconditioned spaces
(attics and crawl spaces) shall be weather-stripped and
insulated to a level equivalent to the insulation on the
surrounding surfaces. A wood framed or equivalent
baffle or retainer must be provided when loose fill
insulation is installed the purpose of which is to prevent
insulation from spilling into the living space when the
attic access opened and/or to provide a permanent means
of maintaining the installed R-value of loose-fill
insulation.
90. ATTIC INSULATION: IRC R806, IECC/WSEC
R303.1, R402.2.1, R402.2.1.1 & Table R402.4.1.1..
Ceilings below vented attics shall be insulated to not less
than the nominal R- value specified on the approved
building plans. Unless approved for other than
prescriptive approach the typical R-Value for attic
insulation shall be R-49 installed in a standard manner or
R-38 where the full R-Value extends to the exterior of
the top plate. The thickness of roof/ceiling insulation
that is blown in shall be identified by inches of
thickness, density and R-Value markers shall be installed
at least one for every 300 sq. ft. through the attic/ceiling.
The markers shall be affixed to the trusses or joists and
marked with the minimum initial installed thickness and
the minimum settle thickness with number at least 1” in
height. Each marker shall face the attic access. Loosefill insulation may be used in attic spaces where the
slope of the ceiling is not more than 3’ in 12 and there is
at least 30” attic space. Eave vents shall be provided
with baffles to deflect incoming air above the surface of
the insulation. The baffles shall be rigid material,
resistant to wind driven moisture. The vertical joints
shall be staggered when two or more layers of rigid
board insulation are used. The minimum ventilation
requirements in IRC Section R806.3 and R806.4 shall be
maintained. See also item #76. Baffles shall be
installed so that 1” is maintained between the roof
sheathing and the baffle. The baffles shall be installed
from the top of the outside wall, extending inward, to a
point 6” vertically above the height of non-compressed
insulation, and 12” vertically above loose fill insulation.
93. DUCT INSULATION/DUCT LEAKAGE:.
IECC/WSEC R401.3, R403.2., R403.2.3. IRC chapter
M16,& IMC Chapter 6. Ducts shall be insulated to R-8,
sealed in accordance with R403.2.2, and leak tested .
Ducts or building cavities used for air distribution that
are located entirely within the conditioned space do not
require sealing.
DUCT TIGHTNESS TESTING:The duct system shall
be leak tested in accordance with WSU RS-33, using the
maximum duct leakage rates specified. Duct tightness
shall be verified in accordance to IECC/WSEC R403.2.2
using the post-construction test or rough-in test methods.
Duct leakage tests are not required when ducts and air
handlers located entirely within the building thermal
envelope. Leak test shall be required when ducts are
located in the crawl space. Duct leakage test results
shall be posted on the permanent certificate posted in
accordance with R401.3. See also item #98
94. PIPE INSULATION: R403.4.2. All hot and cold
water pipes installed outside the conditioned space
shall be insulated to a minimum of R-4.
95. VAPOR RETARDER/MOISTURE CONTROL: IRC
R702.7 Class I, II, or III, vapor retarders shall be
installed on the interior side of the framed walls.
Sheet polyethylene, unperforated aluminum foil,
kraft-faced fiberglass batts, latex or enamel paits in
19
glass retained by stops with sealant or caulking all
around.
RECESSED LIGHTING FIXTURES shall be type IC rated, and
ins and certified under ASTM283 to have no more than
2.0 cfm air movement from the conditioned space to the
ceiling cavity. The lighting fixture shall be tested at 75
Pascal’s or 1.57-lbs/sq. ft. pressure difference and have a
label attached, showing with this test method. Recessed
lighting fixtures shall be installed with a gasket or caulk
between the fixture and ceiling to prevent air leakage.
stalled in accordance with manufacturer
specifications are deemed to meet class I, II, or III.
Kraft-faced batts shall be face stapled over studs.
102 GROUND COVER IN CRAWL SPACE: IRC
R406.3.2, IECC/WSEC Table R402.4.1.1. A 6-mil thick
polyethylene film ground cover shall be laid over the
ground within crawl spaces. The ground cover shall be
lapped 6" minimum at the joints and sealed with
adhesive and shall extend to the foundation wall and be
bonded to form a seal. The ground cover may be
omitted in crawl spaces if the crawl space has a concrete
slab with a minimum thickness of 3-1/2".
99. EXHAUST FANS: IRC R303.4, R303.5, M1507.4:
Source specific exhaust ventilation is required in each
kitchen, bathroom, water closet, laundry room, indoor
swimming pool, spa, and other rooms where excess
water vapor or cooking odor is produced as follows:
97. WINDOWS & EXTERIOR DOORS: R402.3.,
R402.1.1. U-Factors for glazing and doors (fenestration)
shall be not more than the U-factor specified on the
approved building plans. Unless approved for other than
prescriptive approach the maximum typical U-factor for
fenestration shall be dependant upon the compliance
method. Typically the max. U-factor for
prescriptively approved structures is U-.30. Any
change in windows or doors must be approved by the
Building Department before installation. NFRC
compliance stickers shall remain on the windows until
the insulation inspection has been approved by the
Building Department. Doors with a glazed area more
than 50%, such as half-lite and full-lite doors, shall be
considered windows for the purposes of energy code
requirements. Up to 15 sq. ft of glazed fenestration
per dwelling unit shall be exempt for U-factor and
SHGC requirements in R402.1. The exception does
not apply to the u-factor compliance approach.
MINIMUM SOURCE SPECIFIC VENTILATION
CAPACITY REQUIREMENTS
TABLE M1507.4
AREA TO BE
EXHAUSTED
EXHAUST RATES
Kitchens or where
100 cfm intermittent
cooking appliances are or 25 cfm continuous
located
Bathrooms and other
50 cfm intermittent or
20 cfm continuous.
wet rooms
NOTE: All fans shall provide the required flow when
tested at .25 water gauge. Ventilation ducts shall
terminate outside the building Ventilation ducts located
in unconditioned spaces shall be insulated to a minimum
of R-4.
98. AIR LEAKAGE INCLUDING RECESSED
LIGHTING FIXTURES: IECC/WSEC R401.3,
R402.4. The building or dwelling shall be tested and
verified as having an air leakage rate not exceeding 5
air changes per hour. Testing shall be conducted
with a blower door in accordance with IECC/WSEC
R402.4.1.2. A written report of the results of the test
shall be signed by the party conducting the test and
provided to the building inspector during the final
inspection. Provisions to limit air leakage shall be
provided to those locations separating outdoor ambient
conditions from interior spaces that are heated or
mechanically cold. Seals & Weather-stripping: a)
Exterior joints around windows and door frames,
openings between walls and foundation, between walls
and roof and wall panels; openings at penetrations of
utility services through walls, floors, and roofs; and at all
other openings in the building envelope, and between
dwelling units shall be sealed, caulked, gasketed or
weather-stripped to limit air leakage. Other exterior
joints and seams and seams shall be similarly treated or
taped, or covered with moisture vapor permeable house
wrap. b) All exterior doors or doors serving as access
to an enclosed unheated area shall be weather-stripped to
limit air leakage around the perimeter when in a closed
position. c) Site built windows are exempt from testing
but shall be made tight fitting. Fixed lites shall have
100. WHOLE HOUSE VENTILATION SYSTEM
Continuous or Intermittent) : IRC M1507.3. Each
dwelling unit or guest room shall be equipped with a
whole house ventilation system that shall be capable of
providing the volume of outdoor air designed in
accordance with IRC M1507.3.1 through M1507.3.7.
Compliance may also be domnstrated through the
International Mechanical Code. Whole house
ventilation systems shall be have a flow rating of .25
inches water gauge and a sone rating of 1.0 or less. The
whole house fan shall be controlled by a 24-hour clock
timer with the capability of continuous operation,
manual and automatic control. At the time of final
inspection, the automatic control timer shall be set to
operate the whole house fan for at least 8 hours a day.
The clock timer shall be readily accessible and be
capable of operating the whole house ventilation fan
without energizing other energy consuming appliances.
A label shall be affixed to the controls that reads “Whole
House Ventilation (see operating instructions).”
101.VENTILATION DUCTS: IRC M1507.3,R303.5, All
ventilation ducts shall terminate outside the building and
20
5.
Intermittent whole-house ventilation systems.
Intermittent whole-house ventilation systems shall comply with
the following:
5.1. They shall be capable of operating intermittently
and continuously.
5.2. They shall have controls capable of operating the
exhaust fans, forced-air system fans, or supply fans
without energizing other energy-consuming appliances.
5.3. The ventilation rate shall be adjusted according to
the exception in Section 403.8.5.1.
5.4. The system shall be designed so that it can operate
automatically based on the type of control timer
installed.
5.5. The intermittent mechanical ventilation system shall
operate at least one hour out of every four.
5.6. The system shall have a manual control and
automatic control, such as a 24-hour clock timer.
5.7. At the time of final inspection, the automatic
control shall be set to operate the whole-house fan
according to the schedule used to calculate the wholehouse fan sizing.
5.8. A label shall be affixed to the control that reads
"Whole House Ventilation (see operating instructions)."
be equipped with a back draft damper. All exhaust ducts
in unconditioned spaces shall be insulated to a minimum
of R-4. All supply ducts located in the conditioned
space shall be insulated to R-4. Fan ducts shall be
equipped with back draft dampers. Terminal elements
shall have at least the equivalent net free area of the
ductwork. Terminal elements for exhaust fan duct
systems shall be screened or otherwise protected from
entry by leaves or other material.
Exhaust Ducts shall be sized in accordance to IMC,
Table 403.8.4.2 and shall not be less than 4-inch
diameter.
Fan
tested
CFM
@.25
WG
Min.
Flex
Diameter
Max.
Lengt
h in
Feet
Min.
Smooth
Diameter
Max.
Lengt
h Feet
Max.
Elbows
50
50
4-inch
5-inch
25
90
4-inch
5-inch
70
100
3
3
50
6-inch
No
Limit
6-inch
No
Limit
3
80
80
4-inch
2
5-inch
NA
15
4-inch
5-inch
20
100
3
3
80
6-inch
90
6-inch
No
Limit
3
100
5-inch2
NA
5-inch
50
3
6-inch
No
Limit
3
100
6-inch
45
1
Operating Instructions and a whole-house ventilation
operation description shall be provided by installers. The
whole-house ventilation system shall provide outdoor air to
each habitable space at a continuous rate not less than that
specified in Table M1507.3.3(1). The system may operate
intermittently when the system has controls that that enable
operation for not less than 25% of each 4-hour segment and
the ventilation rate prescribed in Table M1507.3.3(1) is
multiplied by the factor determined in accordance with Table
M1507.3.3(2).
1. For each additional elbow subtract 10-ft from length
Flex ducts of this diameter are not permitted with fans of
this size.
102. MECHANICAL VENTILATION SYSTEM: IRC
M1507. Each dwelling unit and guest room shall be
provided with a whole house mechanical ventilation
systems designed in accordance with M1507.3.1 through
M1507.3.7 or in accordance with specifications allowed
in the International Mechanical Code.
Outdoor air shall be distributed to each habitable room by
means such as individual inlets, separate duct systems, or
integrated with a forced air system. Where outdoor air
supplies are separated from exhaust points by doors,
provisions shall be made to ensure air flow by installation of
distribution ducts, undercutting doors, installation of grilles,
transoms or other similar means. Doors shall be undercut to a
minimum ½” above of the surface of the finish floor.
Controls and Operation (M1507.3.2):
1. Location of controls. Controls for all ventilation
systems shall be readily accessible by the occupant.
2. Instructions. Operating instructions for whole-house
ventilation systems shall be provided to the occupant by
the installer of the system.
3. Local exhaust systems. Local exhaust systems shall
be controlled by manual switches, dehumidistats, timers,
or other approved means.
4. Continuous whole-house ventilation systems.
Continuous whole-house ventilation systems shall
operate continuously. Exhaust fans, forced-air system
fans, or supply fans shall be equipped with "fan on" as
override controls. Controls shall be capable of operating
the ventilation system without energizing other energyconsuming appliances. A label shall be affixed to the
controls that reads "Whole House Ventilation (see
operating instructions)."
Table M1507.3.3(1)
Continuous Whole-house ventilation system air
flow rates Table M1507.3.3(1)
Dwelling
Unit floor
area (sf)
<1500
1500-3000
3001-4500
4501-6000
0-1
30
45
60
75
Number of bedrooms
2-3
Airflow in CFM
45
60
75
90
4-5
60
75
90
105
Intermittent mechanical fan shall operate not less than one hour every
4-hours. Where the system has controls that enable operation for not
less than 25% every four hours the ventilation rate shall be multiplied
by the factor in Table M1507.3.3(2)
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provided to the inspector during inspection. The system
shall be controlled by a 24-hour clock timer with the
capability of continuous operation, manual and
automatic. This control will control the forced air
system blower and the automatic damper. The 24-hour
timer shall be readily accessible and capable of operating
the whole house ventilation system without energizing
other energy-consuming appliances. At the time of
inspection the automatic control timer shall be set to
operate at least 8-hours a day. A label shall be affixed to
the control that reads, “Whole House Ventilation (see
operating instructions)”.
Table M1507.3.3(2)
Continuous Whole-house ventilation rate factors
Run-time % in each
4-hr period
Factor
25%
33%
50%
66%
75%
4
3
2
1.5
1.3
102 103. WHOLE-HOUSE VENTILATION SYSTEM
USING EXHAUST FANS: IRC M1507.3.4.
Exhaust fans providing whole-house ventilation shall
have a flow rating at 0.25 water guage as specified in
accordance with Table 1507.3.3(1). The whole-house
fan shall sone rating of 1.0 or less measured at 0.1”
w.g. Individual outdoor air inlets shall be provided in
each habitable room and have a) controllable and secure
opening. b) be sleeved or otherwise designed so as not to
compromise the thermal properties of the wall or
window in which they are placed. c) Provide not less
than 4 sq. inches of net free area of opening for each
habitable space. Any inlet or combination of inlets
which provide 10 cfm at 10 Pascals as determined by the
Home Ventilating Institute Air Flow Test Standard (HVI
901 11/96) are deemed equivalent to 4 sq. in. net free
area. Outdoor air inlets (window or wall ports) separated
from fan locations by doors, adequate airflow shall be
ensured by undercutting doors or installing grilles or
transoms. Doors and operable lites in windows are not
deemed to meet the outdoor air supply intake
requirements. Outdoor air inlets shall be screened or
otherwise protected from entry by leaves or other
material. Outdoor air inlets shall be located so as not to
take air from the following areas: a) Closer than 10’
from an appliance vent outlet, unless such vent outlet is
3’ above the outdoor air inlet. b) Where it will pick-up
objectionable odors, fumes or other flammable vapors.
c) A hazardous or unsanitary location. d) A room or
space having and fuel-burning appliances therein. e)
closer than 10’ from any vent opening of a plumbing
drainage system unless the vent is located at least 3’
above the air inlet. f) Attic, crawl spaces, or garages.
105. Intermittent Whole House Ventilation Using a
Supply Fan, IRC M1507.3.6. Supply fan ventilation
systems shall distribute outdoor air to each habitable
room through the forced-air system ducts or through
dedicated ducts to each habitable room. Supply fans
shall have the capacity to provide outdoor air specified
in Table M1507.3.3(1) at .40” w.g. per HVI 916. The
outdoor air must be filtered before it is delivered to
habitable rooms. Ducts shall be installed in accordance
to M1507.3.6.2, dampers in accordance to M1507.3.6.3.
106. Whole House Ventilation using Heat Recovery
Ventilation: M1507.3.7. Heat Recovery ventilation
systems shall be sized and installed in accordance to
manufacturer’s instructions and in accordance to
M1507.3.3(1). Minimum flow rating shall not be less
than that specified in Table M1507.3.3(1).
109. LIGHTING: IECC/WSEC R404 & Chapter 2. A
minimum of 75% of permanently installed lamps in
lighting fixtures shall be high-efficacy lamps. Fuel
gas lighting systems shall not have continuously
buring pilot lights. High efficiency lamps are defined
in Chapter 2 . they include compact fluorescent lamps,
T-8 or smaller diameter lenear fluorescent lamps or
lamps with an efficacy 1) 60 lumens per watt for lamps
over 40 watts; 2) 50 lumens per watt for lamps over 15
watts to 40 watts; 3) 40 lumens per watt for lamps 15
watts or less.
104. INTERMITTENT WHOLE HOUSE
VENTILATION INTEGRATED WITH A
FORCED-AIR SYSTEM. (Make-up air through the
furnace): IRC M1507.5. Integrated ventilation systems
shall provide outdoor air at the rate calculated using
Table M1507.3.3. The ventilation system shall distribute
outdoor air to each habitable room through the forced-air
system ducts. The outside air inlet duct shall terminate
outside of the building and be connected to the return air
plenum of the forced air system at a point within 4-ft
upstream of the air handler. The outdoor inlet shall be
connected upstream of the forced air system blower and
shall not be connected directly into the furnace cabinet.
The system shall be provided with a motorized damper
connected to the automatic ventilation control as
specified in M1507.3.2. The required flow rate shall be
verified by field-testing with a flow hood or a flow
measuring station. A copy of the testing report shall be
FIRE APPARATUS ACCESS ROADS
110. FIRE ACCESS: Mason County Title 14, Chapter
14.17 Standards for Fire Apparatus Access Roads. All
roads, driveways, or other means of access serving
structures, facilities, buildings or portions of buildings
hereafter constructed, altered, moved into, or within, the
jurisdiction and developed under permit from Mason
County shall meet the requirements of the fire apparatus
access road standards. (see detail pages contained within
this checklist).
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