The Ontario Building Code | Ground Cover in Heated Crawl Spaces
9.18.6.2. Ground Cover in Heated Crawl Spaces
(1) Where a crawl space is heated, a ground cover consisting of not less than 0.15 mm polyethylene sheet conforming to CAN/cgsb-51.34-M, "Vapour Barrier, Polyethylene Sheet, for Use in building Construction", shall be installed as part of an air barrier system in accordance with Subsection 9.25.3.
(2) The ground cover required in Sentence (1) shall,
(a) have its joints lapped not less than 300 mm, and sealed and weighted down, or
(b) be covered with a concrete skim coat not less than 50 mm thick.
(3) The perimeter of the ground cover required in Sentence (1) shall be sealed to the foundation wall.
9.18.7. Fire Protection
In Plain Language
Heated crawl spaces have their own ground cover requirements set out in this article, consistent with treating this space more like conditioned living space.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.