Section 422.160 Mitigation Standard for New Residential Construction

Section 422.160  Mitigation Standard for New Residential

Construction

a)         General

Practices.  This Section contains the requirements for new construction in

Illinois in accordance with the Radon Resistant Construction Act [420 ILCS

52].  The following required construction methods are intended to resist radon

entry and prepare the building for post-construction radon mitigation, if

necessary.  These techniques are required in all areas of Illinois.

b)         Subfloor

Preparation.  A layer of gas-permeable material shall be placed under all

concrete slabs and other floor systems that directly contact the ground and are

within the walls of the living spaces of the buildings, to facilitate future

installation of a sub-slab depressurization system, if needed.  The gas

permeable layer shall consist of one of the following:

1)         A

uniform layer of clean aggregate, a minimum of 4 inches (102 mm) thick.  The

aggregate shall consist of material that will pass through a 2 inch (51 mm)

sieve and be retained by a ¼ inch (6.4 mm) sieve; or

2)         A

uniform layer of sand (native or fill), a minimum of 4 inches (102 mm) thick, overlain

by a layer or strips of geo-textile drainage matting designed to allow the

lateral flow of soil gases.  The geotextile matting shall have a

cross-sectional area of not less than 12 square inches (77 sq. cm) and shall be

placed, at a minimum, along the entire inside perimeter of the foundation at a

distance of 12 to 18 inches (30 to 46 cm) distance from the foundation wall to

the edge of the drainage matting.  Deviation from the 12 to 18 inches (30 to 46

cm) distance to the foundation wall shall be allowed to avoid obstacles such as

plumbing and other utilities; or

3)         Other

materials, systems or floor designs with demonstrated capability to permit

depressurization across the entire subfloor area.

c)         Soil Gas

Retarder

ce from the foundation wall to

the edge of the drainage matting.  Deviation from the 12 to 18 inches (30 to 46

cm) distance to the foundation wall shall be allowed to avoid obstacles such as

plumbing and other utilities; or

3)         Other

materials, systems or floor designs with demonstrated capability to permit

depressurization across the entire subfloor area.

c)         Soil Gas

Retarder.  A minimum 6-mil (0.15 mm) (or 3-mil (0.075 mm) cross‑laminate)

polyethylene or equivalent flexible sheeting material shall be placed on top of

the gas permeable layer prior to casting the slab or placing the floor assembly

to serve as a soil gas retarder by bridging any cracks that develop in the slab

or floor assembly and to prevent concrete from entering the void spaces in the

aggregate base material.  The sheeting shall cover the entire floor area with

separate sections of sheeting lapped at least 12 inches (305 mm).  The sheeting

shall fit closely around any pipe, wire or other penetrations of the material.

All punctures or tears in the material shall be sealed or covered with

additional sheeting.

d)         Entry

Routes.  Potential radon entry routes shall be closed in accordance with the

following:

1)         Floor

openings around bathtubs, showers, water closets, pipes, wires or other objects

that penetrate concrete slabs or other floor assemblies shall be filled with a

polyurethane caulk or equivalent sealant applied in accordance with the

manufacturer's recommendations.

2)         All

concrete control joints, isolation joints, construction joints and any other

joints in concrete slabs or between slabs and foundation walls shall be sealed

with a polyurethane caulk.  Gaps and joints shall be cleared of loose material

and filled with polyurethane caulk applied in accordance with the manufacturer's

recommendations.

3)         Condensate

drains shall be trapped or routed through non-perforated pipe to daylight

n joints, construction joints and any other

joints in concrete slabs or between slabs and foundation walls shall be sealed

with a polyurethane caulk.  Gaps and joints shall be cleared of loose material

and filled with polyurethane caulk applied in accordance with the manufacturer's

recommendations.

3)         Condensate

drains shall be trapped or routed through non-perforated pipe to daylight.

4)         Sump

pits open to soil or serving as the termination point for subslab or exterior

drain tile loops shall be covered with a gasketed or otherwise sealed lid.

Sump pits shall not be used as a primary suction point in a sub-slab

depressurization system.  Sumps used as a floor drain shall have a lid equipped

with a trapped inlet.

5)         Hollow

block masonry foundation walls shall be constructed with either a continuous

course of solid masonry, one course of masonry grouted solid, or a solid

concrete beam at or above finished ground surface to prevent passage of air

from the interior of the wall into the living space.  Where a brick veneer or

other masonry ledge is installed, the course immediately below that ledge shall

be sealed.  Joints, cracks or other openings around all penetrations of both

exterior and interior surfaces of masonry block or wood foundation walls below

the ground surface shall be filled with polyurethane caulk or equivalent

sealant.  Penetrations of concrete walls shall be filled.

6)         The

exterior surfaces of concrete and masonry block walls below the ground surface

shall be damp-proofed in accordance with Section R406 of the 2012 International

Residential Code for One- and Two-Family Dwellings (copyrighted 2011 by the

International Code Council, Inc.; incorporated by reference in accordance with

Section 422.15).

7)         Air-handling

units shall be sealed to prevent air from being drawn into the unit.  Units

with gasketed seams or units that are otherwise sealed by the manufacturer to

prevent leakage are exempted from this requirement

ential Code for One- and Two-Family Dwellings (copyrighted 2011 by the

International Code Council, Inc.; incorporated by reference in accordance with

Section 422.15).

7)         Air-handling

units shall be sealed to prevent air from being drawn into the unit.  Units

with gasketed seams or units that are otherwise sealed by the manufacturer to

prevent leakage are exempted from this requirement.

8)         Underground

and crawlspace duct systems shall be sealed in accordance with Section M1601.4.1

of the 2012 International Residential Code for One- and Two-Family Dwellings

(copyrighted 2011 by the International Code Council, Inc.; incorporated by

reference in accordance with Section 422.15).

9)         Openings

around all penetrations through floors above crawlspaces shall be caulked or

otherwise filled to prevent air leakage.

10)         Access

doors and other openings or penetrations into crawlspaces shall be closed,

gasketed or otherwise sealed to prevent air leakage.

e)         Passive

Sub-membrane Depressurization (SMD) System.  In buildings with crawlspace

foundations or earthen floors, the following components of a passive SMD system

shall be installed during construction.

1)         Crawlspaces

shall be provided with vents to the exterior of the building in accordance with

Section R408 of the 2012 International Residential Code for One- and Two‑Family

Dwellings.

2)         The

soil in crawlspaces shall be covered with a continuous layer of minimum 6-mil

(0.15 mm) polyethylene soil gas retarder.  The ground cover shall be lapped a

minimum of 12 inches (305 mm) at joints and shall extend to all foundation

walls enclosing the crawlspace area.

3)         Any

seams in soil gas retarder membranes shall be overlapped at least 12 inches and

sealed in a permanent air tight manner using compatible glues

covered with a continuous layer of minimum 6-mil

(0.15 mm) polyethylene soil gas retarder.  The ground cover shall be lapped a

minimum of 12 inches (305 mm) at joints and shall extend to all foundation

walls enclosing the crawlspace area.

3)         Any

seams in soil gas retarder membranes shall be overlapped at least 12 inches and

sealed in a permanent air tight manner using compatible glues.  The membrane

shall also be sealed around interior piers and to the inside of exterior walls

with furring strips and compatible glues or in accordance with specific

procedures submitted by radon contractors as part of their license application

and approved by the Agency.

4)         A

plumbing tee or other approved connection fitted with not less than 5 feet (105

m) of perforated pipe extending from each horizontal opening of the tee shall

be inserted horizontally beneath the sheeting and connected to a 3- or 4-inch

diameter (76 mm or 102 mm) fitting with a vertical vent pipe installed through

the sheeting.  The vent pipe shall be extended up through the building floors,

terminate at least 12 inches (305 mm) above the penetration in the highest roof

in a location at least 2 feet (609.6 mm) above any window or other opening into

the conditioned spaces of the building and 10 feet (3048 mm) from any window or

other opening in adjoining or adjacent buildings.

f)         Passive

Sub-slab Depressurization (SSD) System.  Buildings with a basement, crawlspace

or slab-on grade concrete floor in contact with the earth or grade shall have

the following components of a passive SSD system that shall be installed during

construction.

1)         A

minimum 3-inch diameter (76 mm) Schedule 40 PVC shall be embedded vertically

into the sub-slab aggregate or other permeable material before the slab is cased

(SSD) System.  Buildings with a basement, crawlspace

or slab-on grade concrete floor in contact with the earth or grade shall have

the following components of a passive SSD system that shall be installed during

construction.

1)         A

minimum 3-inch diameter (76 mm) Schedule 40 PVC shall be embedded vertically

into the sub-slab aggregate or other permeable material before the slab is cased.

A)        A

plumbing tee or other approved connection fitted with not less than 5 feet (105

m) of perforated pipe extending from each horizontal opening of the tee shall

be inserted horizontally within the sub-slab permeable material to ensure that

the pipe opening remains within the sub-slab.  Alternatively, the 3-inch (76

mm) pipe shall be inserted directly into an interior perimeter drain tile

loop.  The vent pipe shall be extended up through the building floors,

terminate at least 12 inches (305 mm) above the highest roof in a location of

at least 2 feet (609.6 mm) above any window or other opening into the

conditioned spaces of the building and 10 feet (3048 mm) from any window or

other opening in adjoining or adjacent buildings; or

B)        A

penetration into the sub-slab permeable material may be cored through sub-slab

after the slab is cased.  A minimum 3-inch diameter (76 mm) Schedule 40 PVD

shall be embedded vertically into the sub-slab aggregate or other permeable

material and extended up through the building floors, terminate at least 12

inches (305 mm) above the penetration in the highest roof in a location at

least 2 feet (609.6 mm) above any window or other opening into the conditioned

spaces of the building and 10 feet (3048 mm) from any window or other opening

in adjoining or adjacent buildings.

2)         In

buildings where interior footings or other barriers separate the sub-slab

aggregate or other gas-permeable material, each area shall be fitted with an

individual vent pipe

n a location at

least 2 feet (609.6 mm) above any window or other opening into the conditioned

spaces of the building and 10 feet (3048 mm) from any window or other opening

in adjoining or adjacent buildings.

2)         In

buildings where interior footings or other barriers separate the sub-slab

aggregate or other gas-permeable material, each area shall be fitted with an

individual vent pipe.  Vent pipes shall connect to a single vent that shall

terminate at least 12 inches (305 mm) above the penetration in the highest roof

in a location at least 2 feet (609.6 mm) above any window or other opening into

the conditioned spaces of the building and 10 feet (3048 mm) from any window or

other opening in adjoining or adjacent buildings.

g)         All

components of the radon vent pipe system shall be installed to provide positive

drainage to the ground beneath the slab or soil gas retarder.

h)         Radon

vent pipes shall be accessible for fan installation through an attic or other

area outside and above the habitable space.  The radon vent pipe need not be

accessible in an attic space when an approved roof-top electrical supply is

provided for future use.

i)          All

exposed and visible interior radon vent pipes shall be conspicuously identified

with at least one label on each floor and in accessible attics.  The label

shall read "Radon Reduction System".

j)          Combination

basement/crawlspace or slab-on-grade/crawlspace foundations shall have separate

radon vent pipes installed in each type of foundation area or be connected with

a continuous drain tile loop.  Vent pipes shall connect to a single vent that

shall terminate at least 12 inches (305 mm) above the highest roof in a

location at least 2 feet (609.6 mm) above any window or other opening into the

conditioned spaces of the building and 10 feet (3048 mm) from any window or

other opening in adjoining or adjacent buildings

e of foundation area or be connected with

a continuous drain tile loop.  Vent pipes shall connect to a single vent that

shall terminate at least 12 inches (305 mm) above the highest roof in a

location at least 2 feet (609.6 mm) above any window or other opening into the

conditioned spaces of the building and 10 feet (3048 mm) from any window or

other opening in adjoining or adjacent buildings.

k)         Joints

in air ducts and plenum spaces shall meet the requirements of Section M1601 of

the 2012 International Residential Code for One- and Two-Family Dwellings

(copyrighted 2011 by the International Code Council, Inc.; incorporated by

reference pursuant to Section 422.15).  Thermal envelope air infiltration

requirements shall comply with the energy conservation provisions in Chapter 11

of the 2012 International Residential Code for One- and Two-Family Dwellings

(copyrighted 2011 by the International Code Council, Inc.; incorporated by

reference pursuant to Section 422.15).  Firestopping shall be in conformance

with the most recent general building code enacted by the appropriate local

government or meet the requirements contained in Section R302.11 of the 2012

International Residential Code for One- and Two-Family Dwellings (copyrighted

2011 by the International Code Council, Inc.; incorporated by reference pursuant

to Section 422.15).

l)          To

provide for future installation of an active SMD or SSD system, an electrical

circuit terminated to a single outlet in an accessible approved box shall be

installed during construction in the attic in the anticipated location of vent

pipe fans.

m)         To

provide for future installation of an active SSD, the piping length in the

attic of the building shall have a minimum height of 3 feet to allow for the

anticipated installation of a radon mitigation fan in the vent pipe.

n)          The

juncture of each radon vent pipe with the roof line shall be made water tight

by an approved flashing

e anticipated location of vent

pipe fans.

m)         To

provide for future installation of an active SSD, the piping length in the

attic of the building shall have a minimum height of 3 feet to allow for the

anticipated installation of a radon mitigation fan in the vent pipe.

n)          The

juncture of each radon vent pipe with the roof line shall be made water tight

by an approved flashing.  Lead vent flashings or any other flashing or cap that

would impede the exhaust from the radon vent are prohibited from use.