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Radon

H

Hyrax4978

Registered User
Joined
Nov 28, 2016
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205
Location
Hartford, CT
I am documenting a project in which we are tearing down an existing building and installing a new one in its place. The existing building has a radon mitigation system. So we will put in one for the new building. Where in the code does it talk about radon mitigation systems? when i googled it i find all IRC references, but this project is 2015 IBC.

Thanks,
 
A question was asked of me last week asking for a new SFR, is a radon mitigation system required under the garage slab if the garage has a room over it.

What is everyone's opinion?

excerpt from Appendix F of the IRC

AF103.2 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 building, to facilitate future installation of a subslab depressurization system, if needed.

If you answer yes, then a soil-gas-retarder (6-mil poly or eq. per AF103.3) would be required under the garage slab, even though R506.2.3 has an exception to a vapor retarder under garage slabs because

If you answer no, then what is the intent of the phrase "are within the walls of the living spaces of the building" in section AF103.2
 
Not sure about the IRC, but in our code, we have not interpreted the garage to require radon protection since we do not consider the garage part of the "living space". However, it would need a separation from the remainder of the building, but it already has to be separated from the remainder of the dwelling to prevent the passage of carbon monoxide gas. The material requirements for the CO gas, work for radon as well.
 
jj1289 said:
A question was asked of me last week asking for a new SFR, is a radon mitigation system required under the garage slab if the garage has a room over it.

What is everyone's opinion?

excerpt from Appendix F of the IRC

If you answer yes, then a soil-gas-retarder (6-mil poly or eq. per AF103.3) would be required under the garage slab, even though R506.2.3 has an exception to a vapor retarder under garage slabs because

If you answer no, then what is the intent of the phrase "are within the walls of the living spaces of the building" in section AF103.2
Click to expand...
The exception (R506.2.3 #1) is for "accessory structures" so I believe the intent would be detached...

[RB] ACCESSORY STRUCTURE. A structure that is accessory to and incidental to that of the dwelling(s) and that is located on the same lot.
 
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