Code Library › Volume 1 › Section 9.18 — Crawl Spaces
PART 9 — HOUSING AND SMALL BUILDINGSUpdated for the 2024 Ontario Building Code

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 have its joints lapped not less than 300 mm, and (a) be sealed and evenly weighted down, or (b) be covered with concrete not less than 50 mm thick. (3) The perimeter of the ground cover required in Sentence (1) shall be sealed to the foundation wall. (See Notes A- 9.13.4., A-9.25.3.4. and 9.25.3.6., and A-9.25.3.6.(2) and (3)) (4) All penetrations of the ground cover required in Sentence (1) shall be sealed against air leakage. (See Subsection 9.25.3.)
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Code text is reproduced for reference from the Ontario Building Code (O. Reg. 163/24, 2024 Building Code Compendium). This page is provided for general information and is not an official copy. Always verify requirements against the official Ontario Building Code and confirm with your local building department.