9.13.4.2.Protection from Soil Gas Ingress

r1 (1) Except as provided in Sentence (1.1), all wall, roof and floor assemblies in contact with the ground shall be constructed to resist the leakage of soil gas from the ground into the building in accordance with Subsection 9.25.3. or MMAH Supplementary Standard SB-9, “Requirements for Soil Gas Control.” (1.1) Construction to resist leakage of soil gas into the building is not required for garages and unenclosed portions of buildings. (1.2) Where polyethylene is used to provide a barrier to soil gas ingress through floors-on-ground, it shall conform to CAN/CGSB‑51.34‑M, “Vapour Barrier, Polyethylene Sheet, for Use in Building Construction.” (2) Unless the space between the air barrier system and the ground is designed to be accessible for the future installation of a subfloor depressurization system, dwelling units and buildings containing residential occupancies shall be provided with the rough-in for a radon extraction system conforming to Article 9.13.4.3. (3) Where buildings are used for occupancies other than those described in Sentence (2), protection from radon ingress and the means to address high radon concentrations in the future shall conform to (a) Article 9.13.4.3., or (b) Parts 5 and 6. (See Article 5.4.1.1. and 6.2.1.1.) (See Note A-9.13.4.2.(3))