EXPEDITED RULES
Title of Rule: Chapter 51-13 WAC, Washington State Ventilation and Indoor Air Quality Code.
Purpose: To amend the Washington State Ventilation and Indoor Air Quality Code, chapter 51-13 WAC, to update standards and codes referenced within the document.
Statutory Authority for Adoption: RCW 19.27.190 and 19.27.020.
Statute Being Implemented: Chapters 19.27 and 34.05 RCW.
Summary: Amendments are being made to the Ventilation and Indoor Air Quality Code to update references to the new codes adopted per RCW 19.27.031.
Reasons Supporting Proposal: RCW 19.27.190 and 19.27.020.
Name of Agency Personnel Responsible for Drafting and Implementation: Al Rhoades, Olympia, Washington 98504-8350, (360) 725-2970; and Enforcement: Local jurisdictions.
Name of Proponent: Washington State Building Code Council, governmental.
Rule is not necessitated by federal law, federal or state court decision.
Explanation of Rule, its Purpose, and Anticipated Effects: Chapter 51-13 WAC, Washington State Ventilation and Indoor Air Quality Code, is amended to reference the International Building Code, International Mechanical Code, and the International Fire Code in lieu of the Uniform Building Code, Uniform Mechanical Code, and the Uniform Fire Code. These model codes were changed in statute during the 2003 legislative session. Reference to the National Fire Protection Association Standards 58 and 54 is also added for liquefied petroleum gas installations per RCW 19.27.031(2). Some minor editorial changes have also been made to Sections 201.1503.2.6.
Proposal does not change existing rules.
THIS RULE IS BEING PROPOSED UNDER AN EXPEDITED RULE-MAKING PROCESS THAT WILL ELIMINATE THE NEED FOR THE AGENCY TO HOLD PUBLIC HEARINGS, PREPARE A SMALL BUSINESS ECONOMIC IMPACT STATEMENT, OR PROVIDE RESPONSES TO THE CRITERIA FOR A SIGNIFICANT LEGISLATIVE RULE. IF YOU OBJECT TO THE USE OF THE EXPEDITED RULE-MAKING PROCESS, YOU MUST EXPRESS YOUR OBJECTIONS IN WRITING AND THEY MUST BE SENT TO Tim Nogler, Managing Director, Washington State Building Code Council, P.O. Box 48350, Olympia, WA 98504-8350 , AND RECEIVED BY March 22, 2004.
January 8, 2004
Stan Price
Council Chair
OTS-6581.3
AMENDATORY SECTION(Amending WSR 98-02-047, filed 1/5/98,
effective 7/1/98)
WAC 51-13-106
Conflicts with other codes.
106.1 Conflicts with Other Codes: In addition to the
requirements of this Code, buildings must conform to the
provisions of the State Building Code (chapter 19.27 RCW and
chapters ((51-40, 51-42, 51-44 and 51-46)) 51-50, 51-52, 51-54
and 51-56 Washington Administrative Code). In case of
conflicts between the ((Uniform)) International Building,
Uniform Plumbing, ((Uniform)) International Mechanical, and
((Uniform)) International Fire Codes as adopted and amended in
chapters ((51-40, 51-42, 51-44 and 51-46)) 51-50, 51-52, 51-54
and 51-56 Washington Administrative Code, the provisions of
chapter 51-13 shall govern. This Code is not intended to
abridge any safety or health requirements under any other
applicable codes or ordinances.
Where, in any specific case, different sections of this
Code specify different materials, methods of construction or
other requirements, the most restrictive shall govern. Where
there is a conflict between a general requirement and a
specific requirement, the specific requirement shall be
applicable.
Wherever in this Code reference is made to the appendix,
the provisions of the appendix shall not apply unless
specifically adopted.
106.2 Authority: Local legislative authorities are
authorized and directed to enforce this Code. Local
legislative authorities are authorized to promulgate, adopt,
and issue those rules and regulations necessary for the
effective and efficient administration of this Code.
[Statutory Authority: RCW 19.27.190 and 19.27.020. 98-02-047, § 51-13-106, filed 1/5/98, effective 7/1/98. Statutory Authority: RCW 19.27.190. 95-01-128, § 51-13-106, filed 12/21/94, effective 6/30/95; 91-01-102, § 51-13-106, filed 12/18/90, effective 7/1/91.]
201.1 General: For the purposes of this Code, certain
terms, phrases, words, and their derivatives shall be
construed as specified in this section. Words used is the
singular include the plural and the plural, the singular. Words used in the masculine gender include the feminine and
feminine, the masculine.
Where terms are not defined in this section, the
definitions shall be taken from Chapter 2 of the ((Uniform))
International Building Code.
Where terms are not defined in either this section or
Chapter 2 of the ((Uniform)) International Building Code,
((they)) such terms shall have ((their ordinary)) ordinarily
accepted meanings ((within)) such as the context ((with which
they are used. Webster's Third International Dictionary of the
English Language, Unabridged, copyrighted 1986, shall be
considered as providing ordinarily accepted meanings))
implies.
[Statutory Authority: RCW 19.27.190. 95-01-128, § 51-13-201, filed 12/21/94, effective 6/30/95; 91-01-102, § 51-13-201, filed 12/18/90, effective 7/1/91.]
302.1 Applicability: Group R Occupancies four (4)
stories and less as defined by the Washington State Building
Code shall comply with either this section or Section 303.
302.1.1 Compliance by Calculations or Testing:
Compliance with this section shall be demonstrated through
engineering calculation or performance testing. Documentation
of calculations or performance test results shall be submitted
to the building official. Performance testing shall be
conducted in accordance with recognized test methods.
302.1.2 Minimum Ventilation Performance: Each dwelling
unit or guest room shall be equipped with source specific and
whole house ventilation systems designed and installed to
satisfy the ventilation requirements of this section.
All public corridors shall meet the ventilation
requirements in section ((1203.3)) 1203 of the ((Uniform))
International Building Code.
302.2 Source Specific Ventilation Requirements.
302.2.1 Source Specific Ventilation: 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.
The minimum source specific ventilation effective exhaust
capacity shall be not less than levels specified in Table 3-1.
302.2.2 Source Specific Ventilation Controls: Source
specific ventilation systems shall be controlled by manual
switches, dehumidistats, timers, or other approved means. Source specific ventilation system controls shall be readily
accessible.
302.2.3 Source Specific Ventilation Ducts: Source
specific ventilation ducts shall terminate outside the
building. Exhaust ducts in systems which are designed to
operate intermittently shall be equipped with back-draft
dampers. All exhaust ducts in unconditioned spaces shall be
insulated to a minimum of R-4. Terminal elements shall have
at least the equivalent net free area of the duct work. Terminal elements for exhaust fan duct systems shall be
screened or otherwise protected from entry by leaves or other
material.
302.3 Requirements for Whole House Ventilation Systems.
302.3.1 Whole House Ventilation Systems: Each dwelling
unit shall be equipped with a whole house ventilation system
which shall be capable of providing the volume of outdoor air
specified in Table 3-2 under normal operating conditions.
EXCEPTION:
Maximum flow rates listed in Table 3-2 do not apply to heat recovery ventilation systems.
302.3.2 Whole House Ventilation System Controls: All
ventilation system controls shall be readily accessible. Controls for whole house ventilation systems shall be capable
of operating the ventilation system without energizing other
energy-consuming appliances.
Intermittently operated whole house ventilation systems
shall be constructed to have the capability for continuous
operation, and shall have a manual control and an automatic
control, such as a clock timer. At the time of final
inspection, the automatic control timer shall be set to
operate the whole house fan for at least eight hours a day. A
label shall be affixed to the control that reads "Whole House
Ventilation (see operating instructions)."
302.3.3 Fan Noise: Whole house fans located four feet or
less from the interior grille shall have a sone rating of 1.5
or less measured at 0.1 inches water gauge. Manufacturer's
noise ratings shall be determined as per HVI 915 (October
1995). Remotely mounted fans shall be acoustically isolated
from the structural elements of the building and from attached
duct work using insulated flexible duct or other approved
material.
EXCEPTION:
Whole house ventilation systems which are integrated with forced-air heating systems or heat-recovery
ventilation systems are exempt from the sone rating requirements of this section.
302.3.4 Whole House Ventilation Ducts: All ducts shall
terminate outside the building. Exhaust ducts in systems
which are designed to operate intermittently shall be equipped
with back-draft dampers. All exhaust ducts in unconditioned
spaces shall be insulated to a minimum of R-4. All supply
ducts in the conditioned space shall be insulated to a minimum
of R-4.
302.3.5 Outdoor Air.
302.3.5.1 Outdoor Air Supply: A mechanical system shall
supply outdoor air as required in Section 302.3.1. The
mechanical system may consist of exhaust fans, supply fans, or
both.
302.3.5.2 Outdoor Air Inlets: 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 ten feet from an appliance vent outlet,
unless such vent outlet is three feet above the outdoor air
inlet.
b) Where it will pick up objectionable odors, fumes, or
flammable vapors.
c) A hazardous or unsanitary location.
d) A room or space having any fuel-burning appliances
therein.
e) Closer than ten feet from a vent opening of a plumbing
drainage system unless the vent opening is at least three feet
above the air inlet.
f) Attic, crawl spaces, garages.
302.3.5.3 Outdoor Air Distribution: Outdoor air shall be
distributed to each habitable room by means such as individual
inlets, separate duct systems, or 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 similar means where
permitted by the ((Uniform)) International Building Code. Doors shall be undercut to a minimum of one-half inch above
the surface of the finish floor covering.
302.3.5.4 Doors and operable lites in windows are deemed
not to meet the outdoor air supply intake requirements.
302.3.5.5 Individual Room Outdoor Air Inlets: Where
provided, individual room outdoor air inlets shall:
a) Have controllable and secure openings;
b) Be sleeved or otherwise designed so as not to compromise the thermal properties of the wall or window in which they are placed.
302.3.5.6 Ventilation Integrated with Forced-Air Systems:
Where outdoor air is provided by a forced-air system, the
outdoor air connection to the return air stream shall be
located upstream of the forced-air system blower and shall not
be connected directly into a furnace cabinet to prevent
thermal shock to the heat exchanger.
[Statutory Authority: RCW 19.27.190, 19.27.020. 01-02-099, § 51-13-302, filed 1/3/01, effective 7/1/01. Statutory Authority: RCW 19.27.190. 95-01-128, § 51-13-302, filed 12/21/94, effective 6/30/95. Statutory Authority: RCW 19.27.190(2) and 1992 c 132. 93-02-056, § 51-13-302, filed 1/6/93, effective 7/1/93. Statutory Authority: RCW 19.27.190. 91-01-102, § 51-13-302, filed 12/18/90, effective 7/1/91.]
303.1 Applicability: Group R Occupancies 4 stories or
less shall comply with this section or Section 302. This
section establishes minimum prescriptive design requirements
for intermittently operated systems. Continuously operated
systems shall comply with Section 302. A system which meets
the requirements of this section shall be deemed to satisfy
the requirements of this chapter.
303.2 Minimum Ventilation Performance: Each dwelling
unit or guest room shall be equipped with source specific and
whole house ventilation systems designed and installed to
satisfy the ventilation requirements of this section. All
public corridors shall meet the ventilation requirements in
Section ((1203.3)) 1203 of the ((Uniform)) International
Building Code.
303.3 Source Specific Exhaust Ventilation Requirements.
303.3.1 Source Specific Ventilation: 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. The minimum source specific ventilation effective
exhaust capacity shall be not less than levels specified in
Table 3-1.
303.3.2 Source Specific Exhaust Fans: Exhaust fans
providing source specific ventilation shall have a minimum fan
flow rating not less than 50 cfm at 0.25 inches water gauge
for bathrooms, laundries, or similar rooms and 100 cfm at 0.25
inches water gauge for kitchens. Manufacturers' fan flow
ratings shall be determined as per HVI 916 (April 1995) or
AMCA 210.
| EXCEPTION: | Where a range hood or down draft exhaust fan is used to satisfy the source specific ventilation requirements for kitchens, the range hood or down draft exhaust shall not be less than 100 cfm at 0.10 inches water gauge. |
303.3.4 Source Specific Ventilation Ducts: Source
specific ventilation ducts shall terminate outside the
building. Exhaust ducts shall be equipped with back-draft
dampers. All exhaust ducts in unconditioned spaces shall be
insulated to a minimum of R-4. Terminal elements shall have
at least the equivalent net free area of the duct work. Terminal elements for exhaust fan duct systems shall be
screened or otherwise protected from entry by leaves or other
material.
303.4 Prescriptive Whole House Ventilation Systems:
Whole house ventilation shall be provided by a system that
meets the requirements of either Section 303.3.1, 303.3.2,
303.3.3, or 303.3.4. A system which meets all of the
requirements of one of these sections shall be deemed to
satisfy the requirements for a whole house ventilation system.
303.4.1 Intermittent Whole House Ventilation Using
Exhaust Fans: This section establishes minimum prescriptive
requirements for intermittent whole house ventilation systems
using exhaust fans. A system which meets all the requirements
of this section shall be deemed to satisfy the requirements
for a whole house ventilation system.
303.4.1.1 Whole House Ventilation Fans: Exhaust fans
providing whole house ventilation shall have a flow rating at
0.25 inches water gauge as specified in Table 3-2.
Manufacturers' fan flow ratings shall be determined according
to HVI 916 (April 1995) or AMCA 210.
303.4.1.2 Fan Noise: Whole house fans located four feet
or less from the interior grille shall have a sone rating of
1.5 or less measured at 0.1 inches water gauge. Manufacturer's noise ratings shall be determined as per HVI
915 (October 1995). Remotely mounted fans shall be
acoustically isolated from the structural elements of the
building and from attached duct work using insulated flexible
duct or other approved material.
303.4.1.3 Fan Controls: The whole house ventilation fan
shall be controlled by a 24-hour clock timer with the
capability of continuous operation, manual and automatic
control. The 24-hour timer shall be readily accessible. The
24-hour timer shall be capable of operating the whole house
ventilation fan without energizing other energy-consuming
appliances. At the time of final inspection, the automatic
control timer shall be set to operate the whole house fan for
at least eight hours a day. A label shall be affixed to the
control that reads "Whole House Ventilation (see operating
instructions)."
303.4.1.4 Exhaust Ducts: All exhaust ducts shall
terminate outside the building. Exhaust ducts shall be
equipped with back-draft dampers. All exhaust ducts in
unconditioned spaces shall be insulated to a minimum of R-4.
303.4.1.5 Outdoor Air Inlets: Outdoor air shall be
distributed to each habitable room by individual outdoor air
inlets. 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 similar means where
permitted by the ((Uniform)) International Building Code. Doors shall be undercut to a minimum of one-half inch above
the surface of the finish floor covering.
Individual room outdoor air inlets shall:
a. Have controllable and secure openings;
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 four square 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 (November 1996)) are deemed equivalent to four square inches net free area.
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 feet from an appliance vent outlet, unless such vent outlet is 3 feet above the outdoor air inlet.
b. Where it will pick up objectionable odors, fumes or flammable vapors.
c. A hazardous or unsanitary location.
d. A room or space having any fuel-burning appliances therein.
e. Closer than 10 feet from a vent opening of a plumbing drainage system unless the vent opening is at least 3 feet above the air inlet.
f. Attic, crawl spaces, or garages.
| EXCEPTION: | Exhaust only ventilation systems do not require outdoor air inlets if the home has a ducted forced air heating system that communicates with all habitable rooms and the interior doors are undercut to a minimum of one-half inch above the surface of the finish floor covering. |
303.4.2.1 Integrated Whole House Ventilation Systems:
Integrated Whole House Ventilation Systems shall provide
outdoor air at the rates specified in Table 3-2. Integrated
Forced-Air Ventilation Systems shall distribute outdoor air to
each habitable room through the forced-air system ducts. Integrated Forced-Air Ventilation Systems shall have an
outdoor air inlet duct connecting a terminal element on the
outside of the building to the return air plenum of the
forced-air system, at a point within four (4) feet upstream of
the air handler. The outdoor air inlet duct connection to the
return air stream shall be located upstream of the forced-air
system blower and shall not be connected directly into a
furnace cabinet to prevent thermal shock to the heat
exchanger. The outdoor air inlet duct shall be prescriptively
sized in accordance with Table 3-5. The system will be
equipped with one of the following:
1. A motorized damper connected to the automatic ventilation control as specified in Section 303.3.2.2; or
2. A damper installed and set to meet minimum flow rates as specified in Table 3-2, by either field testing or following manufacturer's installation instructions based on site conditions; or
3. An automatic flow regulated device with field measured or field calculated minimum negative pressure of 0.07 inches water gauge at the point where the outside air duct is connected to the return air plenum.
303.4.2.2 Ventilation Controls: The whole house
ventilation system shall be controlled by a 24-hour clock
timer with the capability of continuous operation, manual and
automatic control. This control will control the forced air
system blower and if applicable the automatic damper. The
24-hour timer shall be readily accessible. The 24-hour timer
shall be capable of operating the whole house ventilation
system without energizing other energy-consuming appliances. At the time of final inspection, the automatic control timer
shall be set to operate the whole house system for at least
eight hours a day. A label shall be affixed to the control
that reads "Whole House Ventilation (see operating
instructions)."
303.4.2.3 Ventilation Duct Insulation: All supply ducts
in the conditioned space shall be insulated to a minimum of
R-4.
303.4.2.4 Outdoor Air Inlets: 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 feet from an appliance vent outlet, unless such vent outlet is 3 feet above the outdoor air inlet.
b. Where it will pick up objectionable odors, fumes or flammable vapors.
c. A hazardous or unsanitary location.
d. A room or space having any fuel-burning appliances therein.
e. Closer than 10 feet from a vent opening of a plumbing drainage system unless the vent opening is at least 3 feet above the air inlet.
f. Attic, crawl spaces, or garages.
303.4.3 Prescriptive Requirements for Intermittent Whole
House Ventilation Using a Supply Fan: This section
establishes minimum prescriptive requirements for intermittent
whole house ventilation systems using an inline supply fan. A
system which meets all the requirements of this section shall
be deemed to satisfy the requirements for a whole house
ventilation system.
303.4.3.1 Outdoor Air: 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 the amount of outdoor air specified in Table 3-2 at
0.4 inches water gauge as per HVI 916 (April 1995). The
outdoor air must be filtered before it is delivered to
habitable rooms. The filter may be located at the intake
device, inline with the fan, or, in the case of a connection
to the return plenum of the airhandler, using the furnace
filter. An outdoor air inlet shall be connected to either the
supply or return air stream.
303.4.3.2 Ducts: An outdoor air inlet duct connection to
the supply air stream shall be located downstream of the
forced-air system blower. An outdoor air inlet duct
connection to the return air stream shall be located at least
four feet upstream of the forced-air system blower and its
filter. Neither type of duct shall be connected directly into
a furnace cabinet to prevent thermal shock to the heat
exchanger. The outdoor air inlet duct shall be prescriptively
sized in accordance with Table 3-6. The terminal element on
the outside of the building shall be sized two inches in
diameter larger than the outdoor air inlet duct.
303.4.3.3 Dampers: The system shall be equipped with a
back-draft damper and one of the following:
1. A calibrated manual volume damper installed and set to meet the measured flow rates specified in Table 3-2 by field testing with a pressure gauge and/or following manufacturer's installation instructions, or
2. A manual volume damper installed and set to meet the measured flow rates specified in Table 3-2 by field testing with a flow hood or a flow measuring station; or
3. An automatic flow-regulating device sized to the specified flow rates in Table 3-2 which provides constant flow over a pressure range of 0.2 to 0.6 inches water gauge.
303.4.3.4 Ventilation Controls: The whole house
ventilation system shall be controlled by a 24 hour clock
timer with the capability of continuous operation, manual and
automatic control. This control will control the inline
supply fan. The 24-hour timer shall be readily accessible. The 24 hour timer shall be capable of operating the whole
house ventilation system without energizing other
energy-consuming appliances. At the time of final inspection,
the automatic control timer shall be set to operate the whole
house system for at least eight hours a day. A label shall be
affixed to the control that reads "Whole House Ventilation
(see operating instructions)."
303.4.3.5 Ventilation Duct Insulation: All supply ducts
in the conditioned space shall be insulated to a minimum of
R-4.
303.4.3.6 Outdoor Air Inlets: 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 feet from an appliance vent outlet, unless such vent outlet is 3 feet above the outdoor air inlet.
b. Where it will pick up objectionable odors, fumes or flammable vapors.
c. A hazardous or unsanitary location.
d. A room or space having any fuel-burning appliances therein.
e. Closer than 10 feet from a vent opening of a plumbing drainage system unless the vent opening is at least 3 feet above the air inlet.
f. Attic, crawl spaces, or garages.
303.4.4 Prescriptive Requirements for Intermittent Whole
House Ventilation Using a Heat Recovery Ventilation System:
This section establishes minimum prescriptive requirements for
intermittent whole house ventilation using a heat recovery
ventilation system.
303.4.4.1 Heat Recovery Ventilation Systems: All duct
work in heat recovery ventilation systems shall be not less
than six inch diameter. Balancing dampers shall be installed
on the inlet and exhaust side. Flow measurement grids shall
be installed on the supply and return. System minimum flow
rating shall be not less than that specified in Table 3-2. Maximum flow rates in Table 3-2 do not apply to heat recovery
ventilation systems.
303.4.4.2 Ventilation Controls: The whole house
ventilation system shall be controlled by a 24 hour clock
timer with the capability of continuous operation, manual and
automatic control. This control will control the inline
supply fan. The 24-hour timer shall be readily accessible. The 24 hour timer shall be capable of operating the whole
house ventilation system without energizing other
energy-consuming appliances. At the time of final inspection,
the automatic control timer shall be set to operate the whole
house system for at least eight hours a day. A label shall be
affixed to the control that reads "Whole House Ventilation
(see operating instructions)."
303.4.4.3 Ventilation Duct Insulation: All supply ducts
in the conditioned space installed upstream of the heat
exchanger shall be insulated to a minimum of R-4.
303.4.4.4 Outdoor Air Inlets: 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 feet from an appliance vent outlet, unless such vent outlet is 3 feet above the outdoor air inlet.
b. Where it will pick up objectionable odors, fumes or flammable vapors.
c. A hazardous or unsanitary location.
d. A room or space having any fuel-burning appliances therein.
e. Closer than 10 feet from a vent opening of a plumbing drainage system unless the vent opening is at least 3 feet above the air inlet.
f. Attic, crawl spaces, or garages.
[Statutory Authority: RCW 19.27.190, 19.27.020. 01-02-099, § 51-13-303, filed 1/3/01, effective 7/1/01. Statutory Authority: RCW 19.27.190(2) and 1992 c 132. 93-02-056, § 51-13-303, filed 1/6/93, effective 7/1/93. Statutory Authority: RCW 19.27.190. 91-01-102, § 51-13-303, filed 12/18/90, effective 7/1/91.]
304.1 Ventilation: The minimum requirements for operable
area to provide natural ventilation are specified in the
((Uniform)) International Building Code (((UBC))) (IBC) as
adopted by the state of Washington.
Where a mechanical ventilation system is installed, the
mechanical ventilation system shall be capable of supplying
ventilation air to each zone with the minimum outdoor air
quantities specified in Table 3-4.
EXCEPTION:
Where occupancy density is known and documented in the plans, the outside air rate may be based on
the design occupant density. Under no circumstance shall the occupancies used result in outside air less
than one-half that resulting from application of Table 3-4 estimated maximum occupancy values.
The outdoor air shall be ducted in a fully enclosed path
directly to every air handling unit in each zone not provided
with sufficient operable area for natural ventilation.
EXCEPTION:
Ducts may terminate within 12 inches of the intake to an HVAC unit provided they are physically
fastened so that the outside air duct is directed into the unit intake.
In all parking garages, other than open parking garages
as defined in ((UBC 311.9)) IBC 406.3, used for storing or
handling of automobiles operating under their own power and on
all loading platforms in bus terminals, ventilation shall be
provided at 1.5 cfm per square foot of gross floor area. The
building official may approve an alternate ventilation system
designed to exhaust a minimum fourteen thousand cfm for each
operating vehicle. Such system shall be based on the
anticipated instantaneous movement rate of vehicles but not
less than 2.5 percent (or one vehicle) of the garage capacity.
Automatic carbon monoxide sensing systems may be submitted
for approval.
In all buildings used for the repair of automobiles, each
repair stall shall be equipped with an exhaust extension duct,
extending to the outside of the building, which if over ten
feet in length, shall mechanically exhaust three hundred cfm. Connecting offices and waiting rooms shall be supplied with
conditioned air under positive pressure.
Combustion air requirements shall conform to the
requirements of Chapter 7 of the ((UMC)) International
Mechanical Code (IMC).
Mechanical refrigerating equipment and rooms storing
refrigerants shall conform to the requirements of Chapter 11
of the ((UMC)) IMC.
304.2 Alternate Systems: Alternate systems designed in
accordance with ASHRAE Standard 62.1.1999 shall be permitted.
TABLE 3-1
Minimum Source Specific Ventilation Capacity
Requirements
| Bathrooms | Kitchens | |
| Intermittently operating | 50 cfm | 100 cfm |
| Continuous operation | 20 cfm | 25 cfm |
TABLE 3-2
Ventilation Rates For All Group R Occupancies four (4) stories and less*
Minimum and Maximum Ventilation Rates: Cubic Feet Per Minute (CFM)
| Floor Area, ft2 |
Bedrooms | |||||||||||||
| 2 or less | 3 | 4 | 5 | 6 | 7 | 8 | ||||||||
| Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | |
| <500 | 50 | 75 | 65 | 98 | 80 | 120 | 95 | 143 | 110 | 165 | 125 | 188 | 140 | 210 |
| 501-1000 | 55 | 83 | 70 | 105 | 85 | 128 | 100 | 150 | 115 | 173 | 130 | 195 | 145 | 218 |
| 1001-1500 | 60 | 90 | 75 | 113 | 90 | 135 | 105 | 158 | 120 | 180 | 135 | 203 | 150 | 225 |
| 1501-2000 | 65 | 98 | 80 | 120 | 95 | 143 | 110 | 165 | 125 | 188 | 140 | 210 | 155 | 233 |
| 2001-2500 | 70 | 105 | 85 | 128 | 100 | 150 | 115 | 173 | 130 | 195 | 145 | 218 | 160 | 240 |
| 2501-3000 | 75 | 113 | 90 | 135 | 105 | 158 | 120 | 180 | 135 | 203 | 150 | 225 | 165 | 248 |
| 3001-3500 | 80 | 120 | 95 | 143 | 110 | 165 | 125 | 188 | 140 | 210 | 155 | 233 | 170 | 255 |
| 3501-4000 | 85 | 128 | 100 | 150 | 115 | 173 | 130 | 195 | 145 | 218 | 160 | 240 | 175 | 263 |
| 4001-5000 | 95 | 143 | 110 | 165 | 125 | 188 | 140 | 210 | 155 | 233 | 170 | 255 | 185 | 278 |
| 5001-6000 | 105 | 158 | 120 | 180 | 135 | 203 | 150 | 225 | 165 | 248 | 180 | 270 | 195 | 293 |
| 6001-7000 | 115 | 173 | 130 | 195 | 145 | 218 | 160 | 240 | 175 | 263 | 190 | 285 | 205 | 308 |
| 7001-8000 | 125 | 188 | 140 | 210 | 155 | 233 | 170 | 255 | 185 | 278 | 200 | 300 | 215 | 323 |
| 8001-9000 | 135 | 203 | 150 | 225 | 165 | 248 | 180 | 270 | 195 | 293 | 210 | 315 | 225 | 338 |
| >9000 | 145 | 218 | 160 | 240 | 175 | 263 | 190 | 285 | 205 | 308 | 220 | 330 | 235 | 353 |
| *For residences that exceed 8 bedrooms, increase the minimum requirement listed for 8 bedrooms by an additional 15 CFM per bedroom. The maximum CFM is equal to 1.5 times the minimum. | ||||||||||||||
TABLE 3-3
Prescriptive Exhaust Duct Sizing
| Fan
Tested CFM @ 0.25 W.G. |
Minimum Flex Diameter |
Maximum Length Feet |
Minimum Smooth Diameter |
Maximum Length Feet |
Maximum Elbows1 |
| 50 | 4 inch | 25 | 4 inch | 70 | 3 |
| 50 | 5 inch | 90 | 5 inch | 100 | 3 |
| 50 | 6 inch | No Limit | 6 inch | No Limit | 3 |
| 80 | 4 inch2 | NA | 4 inch | 20 | 3 |
| 80 | 5 inch | 15 | 5 inch | 100 | 3 |
| 80 | 6 inch | 90 | 6 inch | No Limit | 3 |
| 100 | 5 inch2 | NA | 5 inch | 50 | 3 |
| 100 | 6 inch | 45 | 6 inch | No Limit | 3 |
| 125 | 6 inch | 15 | 6 inch | No Limit | 3 |
| 125 | 7 inch | 70 | 7 inch | No Limit | 3 |
| 1. | For each additional elbow subtract 10 feet from length. |
| 2. | Flex ducts of this diameter are not permitted with fans of this size. |
TABLE 3-4
Outdoor air requirements for ventilation1
Occupancies not subject to sections 302 and 303
| Application | Estimated Maximum2Occupancy P/1000 ft2 or 100 m2 |
Outdoor Air Requirements cfm/person |
| Dry Cleaners, Laundries3 | ||
| Commercial laundry | 10 | 25 |
| Commercial dry cleaner | 30 | 30 |
| Storage, pick up | 30 | 35 |
| Coin-operated laundries | 20 | 15 |
| Coin-operated dry cleaner | 20 | 15 |
| Dwelling Units In Buildings Greater Than Four Stories or Attached to
I- Occupancy Facilities |
||
| Bedroom & living area24 | 15 | |
| Food and Beverage Service | ||
| Dining rooms | 70 | 20 |
| Cafeteria, fast food | 100 | 20 |
| Bars, cocktail lounges4 | 100 | 30 |
| Kitchens (cooking)23 | 20 | 15 |
| Garages, Repair, Service Stations | ||
| Enclosed parking garage5 | 1.50 cfm/ft.sq. | |
| Auto repair rooms | 1.50 cfm/ft.sq. | |
| Hotels, Motels, Resorts, Congregate Residences with More Than
Four Stories6 |
||
| Bedrooms | 30 cfm/room | |
| Living Rooms | 30 cfm/room | |
| Bath7 | 35 cfm/room | |
| Lobbies | 30 | 15 |
| Conference rooms | 50 | 20 |
| Assembly rooms | 120 | 15 |
| Gambling casinos4 | 120 | 30 |
| Offices | ||
| Office space9 | 7 | 20 |
| Reception area | 60 | 15 |
| Telecommunication centers and data entry areas |
60 | 20 |
| Conference rooms | 50 | 20 |
| Public Spaces | ||
| Corridors and utilities | 0.05 cfm/ft.sq. | |
| Public restroom, cfm/wc or urinal10 |
50 | |
| Lockers and dressing rooms | 0.50 cfm/ft.sq. | |
| Smoking lounge11 | 70 | 60 |
| Elevators12 | 1.0 cfm/ft.sq. | |
| Retail Stores, Sales Floors, and Show Room Floors | ||
| Basement and street | 30 | 0.30 cfm/ft.sq. |
| Upper floors | 20 | 0.20 cfm/ft.sq. |
| Storage rooms | 15 | 0.15 cfm/ft.sq. |
| Dressing rooms | 0.20 cfm/ft.sq. | |
| Malls and arcades | 20 | 0.20 cfm/ft.sq. |
| Shipping and receiving | 10 | 0.15 cfm/ft.sq. |
| Smoking lounge11 | 70 | 60 |
| Warehouses | 5 | 0.05 cfm/ft.sq. |
| Speciality Shops | ||
| Barber | 25 | 15 |
| Beauty | 25 | 25 |
| Reducing salons | 20 | 15 |
| Florists13 | 8 | 15 |
| Clothiers, furniture | 0.30 cfm/ft.sq. | |
| Hardware, drugs, fabric | 8 | 15 |
| Supermarkets | 8 | 15 |
| Pet shops | 1.00 cfm/ft.sq. | |
| Sports and Amusement14 | ||
| Spectator areas | 150 | 15 |
| Game rooms | 70 | 25 |
| Ice arenas (playing areas) | 0.50 cfm/ft.sq. | |
| Swimming Pools (pool and deck area)15 |
0.50 cfm/ft.sq. | |
| Playing floor (gymnasium) | 30 | 20 |
| Ballrooms and discos | 100 | 25 |
| Bowling alleys (seating areas) | 70 | 25 |
| Theaters16 | ||
| Ticket booths | 60 | 20 |
| Lobbies | 150 | 20 |
| Auditorium | 150 | 20 |
| Stages, studios | 70 | 15 |
| Transportation17 | ||
| Waiting rooms | 100 | 15 |
| Platforms | 100 | 15 |
| Vehicles | 150 | 15 |
| Workrooms | ||
| Meat processing18 | 10 | 15 |
| Photo studios | 10 | 15 |
| Darkrooms | 10 | 0.50 cfm/ft.sq. |
| Pharmacy | 20 | 15 |
| Bank vaults | 5 | 15 |
| Duplicating, printing19 | 0.50 cfm/ft.sq. | |
| INSTITUTIONAL FACILITIES | ||
| Education | ||
| Classroom | 50 | 15 |
| Laboratories20 | 30 | 20 |
| Training shop | 30 | 20 |
| Music rooms | 50 | 15 |
| Libraries | 20 | 15 |
| Locker rooms | 0.50 cfm/ft.sq. | |
| Corridors | 0.10 cfm/ft.sq. | |
| Auditoriums | 150 | 15 |
| Smoking lounges11 | 70 | 60 |
| Hospitals, Nursing and Convalescent Homes | ||
| Patient rooms21 | 10 | 25 |
| Medical procedure | 20 | 15 |
| Operating rooms | 20 | 30 |
| Recovery and ICU | 20 | 15 |
| Autopsy rooms22 | 0.50 cfm/ft.sq. | |
| Physical Therapy | 20 | 15 |
| Correctional Facilities | ||
| Cells | 20 | 20 |
| Dining halls | 100 | 15 |
| Guard station | 40 | 15 |
| 1. | Derived from ASHRAE Standard 62-1989. |
| 2. | Net occupiable space. |
| 3. | Dry-cleaning process may require more air. |
| 4. | Supplementary smoke-removal equipment may be required. |
| 5. | Distribution among people must consider worker location and concentration of running engine; stands where engines are run must incorporate systems for positive engine exhaust withdrawal. Contaminant sensors may be used to control ventilation. |
| 6. | Independent of room size. |
| 7. | Installed capacity for intermittent use. |
| 8. | See also food and beverage service, merchandising, barber and beauty shops, garages. |
| 9. | Some office equipment may require local exhaust. |
| 10. | Mechanical exhaust with no recirculation is recommended. |
| 11. | Normally supplied by transfer air, local mechanical exhaust; with no recirculation recommended. |
| 12. | Normally supplied by transfer air. |
| 13. | Ventilation to optimize plant growth may dictate requirements. |
| 14. | When internal combustion engines are operated for maintenance of playing surfaces, increased ventilation rates may be required. |
| 15. | Higher values may be required for humidity control. |
| 16. | Special ventilation will be needed to eliminate special stage effects. |
| 17. | Ventilation within vehicles may require special considerations. |
| 18. | Spaces maintained at low temperatures (-10°F. to+ 50°F.) are not covered by these requirements unless the occupancy is continuous. Ventilation from adjoining spaces is permissible. When the occupancy is intermittent, infiltration will normally exceed the ventilation requirements. |
| 19. | Installed equipment must incorporate positive exhaust and control of undesirable contaminants. |
| 20. | Special contamination control systems may be required for processes or functions including laboratory animal occupancy. |
| 21. | Special requirements or codes and pressure relationships may determine minimum ventilation rates and filter efficiency. Procedures generating contaminants may require higher rates. |
| 22. | Air shall not be recirculated into other spaces. |
| 23. | Makeup air for hood exhaust may require more ventilating air. |
| 24. | Occupant loading shall be based on the number of bedrooms as follows: first bedroom, two persons; each additional bedroom, one person. Where higher occupant loadings are known, they shall be used. |
TABLE 3-5
Prescriptive Integrated Forced Air Supply Duct Sizing
| Required Flow (CFM) Per Table 3-2 |
Minimum Smooth Duct Diameter |
Minimum Flexible Duct Diameter |
Maximum Length1 |
Maximum Number of Elbows2 |
| 50-80 | 6" | 7" | 20' | 3 |
| 80-125 | 7" | 8" | 20' | 3 |
| 115-175 | 8" | 10" | 20' | 3 |
| 170-240 | 9" | 11" | 20' | 3 |
| 1. | For lengths over 20 feet increase duct diameter 1 inch. |
| 2. | For elbows numbering more than 3 increase duct diameter 1 inch. |
| Supply Fan Tested CFM At 0.4" WG | ||
| Specified volume from Table 3-2 |
Minimum Smooth Duct Diameter |
Minimum Flexible Duct Diameter |
| 50-90 CFM | 4 inch | 5 inch |
| 90-150 CFM | 5 inch | 6 inch |
| 150-250 CFM | 6 inch | 7 inch |
| 250-400 CFM | 7 inch | 8 inch |
[Statutory Authority: RCW 19.27.190, 19.27.020. 01-02-099, § 51-13-304, filed 1/3/01, effective 7/1/01. Statutory Authority: RCW 19.27.190. 95-01-128, § 51-13-304, filed 12/21/94, effective 6/30/95. Statutory Authority: RCW 19.27.190(2) and 1992 c 132. 93-02-056, § 51-13-304, filed 1/6/93, effective 7/1/93. Statutory Authority: RCW 19.27.190. 91-01-102, § 51-13-304, filed 12/18/90, effective 7/1/91.]
402.1 General: Solid fuel burning appliances and
fireplaces shall satisfy one of the following criteria.
402.2 Solid Fuel Burning Appliances: Solid fuel burning
appliances shall be provided with the following:
a) Tight fitting metal or ceramic glass doors.
b) 1. A source from outside the structure of primary
combustion air, connected to the appliance as per
manufacturer's specification. The air inlet shall originate
at a point below the fire box. The duct shall be 4 inches or
greater in diameter, not exceed 20 feet in length, and be
installed as per manufacturer's instructions;
A) Negative pressure of 8 Pascal shall be initially
established with the chamber sealed and the air supply, if not
directly connected to the appliance, closed off.
B) The air supply, if not directly connected to the
appliance, shall then be opened.
C) The maximum allowable air exchange rate from chamber
leakage and intentional air supply for the unit (appliance
with combustion air supply) in the test chamber is 3.5 air
changes per hour, or 28 cfm (cubic feet of air per minute),
whichever is less.
EXCEPTION:
Combustion air may be supplied to the room in which the solid fuel burning appliance is located in lieu
of direct ducting, provided that one of the following conditions is met:
The combustion air terminus shall be located as close to
the solid fuel burning appliance as possible and shall be
provided with a barometric damper or equivalent. The
combustion air source shall be specified by the manufacturer
or no less than four (4) inches in diameter or the equivalent
in area or as approved.
1) The solid fuel burning appliance is part of a central heating plant and installed in an
unconditioned space in conformance with the ((
Uniform)) International Mechanical Code; or
2) The solid fuel burning appliance is installed in existing construction directly on a concrete floor
or surrounded by masonry materials as in a fireplace.
402.3 Fireplaces: Fireplaces shall be provided with each
of the following:
a) Tightly fitting flue dampers, operated by a readily
accessible manual or approved automatic control.
EXCEPTION:
Fireplaces with gas logs shall be installed in accordance with the ((
Uniform)) International Mechanical
Code section 901, except that the standards for liquefied petroleum gas installations shall be NFPA 58
(Liquefied Petroleum Gas Code) and NFPA 54 (National Fuel Gas Code).
b) An outside source for combustion air ducted into the
firebox. The duct shall be at least six (6) square inches,
and shall be provided with an operable outside air duct
damper.
EXCEPTION:
Washington certified fireplaces shall be installed with the combustion air systems necessary for their
safe and efficient combustion and specified by the manufacturer in accordance with the Washington
state ((
UBC Standard 31-2 (WAC 51-40-31200) and UBC section 3102.5.4 (WAC 51-40-3102)))
building code standard 31-2 (WAC 51-50-31200) and International Building Code Section 2114 (WAC 51-50-2114).
c) Site built fireplaces shall have tight fitting glass
or metal doors, or a flue draft induction fan, or as approved
for minimizing back-drafting. Factory built fireplaces shall
use doors listed for the installed appliance.
402.4 Masonry Heaters: Masonry heaters shall be approved
by the department of ecology and shall contain both of the
following:
a) Primary combustion air ducted from the outside of the
structure to the appliance.
b) Tight fitting ceramic glass or metal doors. Flue
damper, when provided, shall have an external control and when
in the closed position shall have a net free area of not less
than five percent of the flue cross sectional area.
[Statutory Authority: RCW 19.27.190 and 19.27.020. 98-02-047, § 51-13-402, filed 1/5/98, effective 7/1/98. Statutory Authority: RCW 19.27.190. 95-01-128, § 51-13-402, filed 12/21/94, effective 6/30/95. Statutory Authority: RCW 19.27.190(2) and 1992 c 132. 93-02-056, § 51-13-402, filed 1/6/93, effective 7/1/93. Statutory Authority: RCW 19.27.190. 91-01-102, § 51-13-402, filed 12/18/90, effective 7/1/91.]
502.1 Crawlspaces:
502.1.1 General: All crawlspaces shall comply with the
requirements of this section.
502.1.2 Ventilation: All crawlspaces shall be ventilated
as specified in section ((2306.7)) 1203.3 of the ((Washington
State Uniform)) International Building Code (chapter ((51-40))
51-50 WAC).
If the installed ventilation in a crawlspace is less than
one square foot for each three hundred square feet of
crawlspace area, or if the crawlspace vents are equipped with
operable louvers, a radon vent shall be installed to originate
from a point between the ground cover and soil. The radon
vent shall be installed in accordance with sections 503.2.6
and 503.2.7.
502.1.3 Crawlspace Plenum Systems: In crawlspace plenum
systems used for providing supply air for an HVAC system,
aggregate, a permanently sealed soil gas retarder membrane and
a radon vent pipe shall be installed in accordance with
section 503.2. Crawlspaces shall not be used for return air
plenums.
In addition, an operable radon vent fan shall be
installed. The fan shall be located as specified in section
503.2.7. The fan shall be capable of providing at least one
hundred cfm at one inch water column static pressure. The fan
shall be controlled by a readily accessible manual switch. The switch shall be labeled "RADON VENT FAN."
[Statutory Authority: RCW 19.27.190 and 19.27.020. 98-02-047, § 51-13-502, filed 1/5/98, effective 7/1/98. Statutory Authority: RCW 19.27.190. 95-01-128, § 51-13-502, filed 12/21/94, effective 6/30/95. Statutory Authority: RCW 19.27.190(2) and 1992 c 132. 93-02-056, § 51-13-502, filed 1/6/93, effective 7/1/93. Statutory Authority: RCW 19.27.190. 91-12-045, § 51-13-502, filed 6/5/91, effective 7/1/91; 91-01-102, § 51-13-502, filed 12/18/90, effective 7/1/91.]
503.1 Scope: This section applies to those counties
specified in section 501.2.2. This section establishes
prescriptive construction requirements for reducing the
potential for radon entry into all Group R Occupancies, and
for preparing the building for future mitigation if desired.
In all crawlspaces, except crawlspace plenums used for
providing supply air for an HVAC system, a continuous air
barrier shall be installed between the crawlspace area and the
occupied area to limit air transport between the areas. If a
wood sheet subfloor or other material is utilized as an air
barrier, in addition to the requirements of section 502.1.6.2
of the Washington state energy code, all joints between sheets
shall be sealed.
503.2 Floors in Contact with the Earth
503.2.1 General: Concrete slabs that are in direct
contact with the building envelope shall comply with the
requirements of this section.
EXCEPTION:
Concrete slabs located under garages or other than Group R Occupancies need not comply with this
chapter.
503.2.2 Aggregate: A layer of aggregate of four inch
minimum thickness shall be placed beneath concrete slabs. The
aggregate shall be continuous to the extent practical.
503.2.3 Gradation: Aggregate shall:
a) Comply with ASTM Standard C-33 Standard Specification
for Concrete Aggregate and shall be size No. 8 or larger size
aggregate as listed in Table 2, Grading Requirements for
Coarse Aggregate; or
b) Meet the 1988 Washington State Department of
Transportation specification 9-03.1 (3) "Coarse Aggregate for
Portland Cement Concrete," or any equivalent successor
standards. Aggregate size shall be of Grade 8 or larger as
listed in section 9-03.1 (3) C, "Grading"; or
c) Be screened, washed pea gravel free of deleterious
substances in a manner consistent with ASTM Standard C-33 with
one hundred percent (100%) passing a one-half (1/2) inch sieve
and less than five percent (5%) passing a No. 16 sieve. Sieve
characteristics shall conform to those acceptable under ASTM
Standard C-33.
EXCEPTION:
Aggregate shall not be required if a substitute material or system, with sufficient load bearing
characteristics, and having approved capability to provide equal or superior air flow, is installed.
503.2.4 Soil-Gas Retarder Membrane: A soil-gas retarder
membrane, consisting of at least one layer of virgin
polyethylene with a thickness of at least six mil, or
equivalent flexible sheet material, shall be either placed
directly under all concrete slabs so that the slab is in
direct contact with the membrane, or on top of the aggregate
with two inches (2") minimum of fine sand or pea gravel
installed between the concrete slab and membrane. The
flexible sheet shall extend to the foundation wall or to the
outside edge of the monolithic slab. Seams shall overlap at
least twelve inches. The membrane shall also be fitted
tightly to all pipes, wires, and other penetrations of the
membrane and sealed with an approved sealant or tape. All
punctures or tears shall be repaired with the same or approved
material and similarly lapped and sealed.
503.2.5 Sealing of Penetrations and Joints: All
penetrations and joints in concrete slabs or other floor
systems and walls below grade shall be sealed by an approved
sealant to create an air barrier to limit the movement of
soil-gas into the indoor air.
Sealants shall be approved by the manufacturer for the
intended purpose. Sealant joints shall conform to
manufacturer's specifications. The sealant shall be placed
and tooled in accordance with manufacturer's specifications. There shall be no gaps or voids after the sealant has cured.
503.2.6 Radon Vent: One continuous sealed pipe shall run
from a point within the aggregate under each concrete slab to
a point outside the building. Joints and connections shall be
permanently gas tight. The continuous sealed pipe shall
interface with the aggregate in the following manner, or by
other approved equal method: The pipe shall be permanently
connected to a "T" within the aggregate area so that the two
end openings of the "T" lie within the aggregate area. A
minimum of five feet of perforated drain pipe of three inches
minimum diameter shall join to and extend from the "T."
The perforated pipe shall remain in the aggregate area
and shall not be capped at the ends. The "T" and ((it's)) its
perforated pipe extensions shall be located at least five feet
horizontally from the exterior perimeter of the aggregate
area.
The continuous sealed pipe shall terminate no less than
twelve inches above the eave, and more than ten horizontal
feet from a woodstove or fireplace chimney, or operable
window. The continuous sealed pipe shall be labeled "radon
vent." The label shall be placed so as to remain visible to
an occupant.
The minimum pipe diameter shall be three inches unless
otherwise approved. Acceptable sealed plastic pipe shall be
smooth walled, and may include either PVC schedule 40 or ABS
schedule of equivalent wall thickness.
The entire sealed pipe system shall be sloped to drain to
the sub-slab aggregate.
The sealed pipe system may pass through an unconditioned
attic before exiting the building; but to the extent
practicable, the sealed pipe shall be located inside the
thermal envelope of the building in order to enhance passive
stack venting.
EXCEPTION:
A fan forced sub-slab depressurization system includes:
| 1) Soil-gas retarder membrane as specified in section 503.2.4; |
|
| 2) Sealing of penetrations and joints as specified in section 503.2.5; |
|
| 3) A three-inch continuous sealed radon pipe shall run from a point within the aggregate under each
concrete slab to a point outside the building; |
|
| 4) Joints and connections (( |
|
| 5) A label of "radon vent" shall be placed on the pipe so as to remain visible to the occupant; |
|
| 6) Fan circuit and wiring as specified in section 503.2.7 and a fan. |
503.2.7 Fan Circuit and Wiring and Location: An area for
location of an in-line fan shall be provided. The location
shall be as close as practicable to the radon vent pipe's
point of exit from the building, or shall be outside the
building shell; and shall be located so that the fan and all
downstream piping is isolated from the indoor air.
Provisions shall be made to allow future activation of an
in-line fan on the radon vent pipe without the need to place
new wiring. A one hundred ten volt power supply shall be
provided at a junction box near the fan location.
503.2.8 Separate Aggregate Areas: If the four-inch
aggregate area underneath the concrete slab is not continuous,
but is separated into distinct isolated aggregate areas by a
footing or other barrier, a minimum of one radon vent pipe
shall be installed into each separate aggregate area.
EXCEPTION:
Separate aggregate areas may be considered a single area if a minimum three-inch diameter connection
joining the separate areas is provided for every thirty feet of barrier separating those areas.
503.2.9 Concrete Block Walls: Concrete block walls
connected to below grade areas shall be considered unsealed
surfaces. All openings in concrete block walls that will not
remain accessible upon completion of the building shall be
sealed at both vertical and horizontal surfaces, in order to
create a continuous air barrier to limit the transport of
soil-gas into the indoor air.
[Statutory Authority: RCW 19.27.190, 19.27.020. 01-02-099, § 51-13-503, filed 1/3/01, effective 7/1/01. Statutory Authority: RCW 19.27.190(2) and 1992 c 132. 93-02-056, § 51-13-503, filed 1/6/93, effective 7/1/93. Statutory Authority: RCW 19.27.190. 91-01-102, § 51-13-503, filed 12/18/90, effective 7/1/91.]