Code Library › Volume 1 › Section 9.16 — Floors-on-Ground
PART 9 — HOUSING AND SMALL BUILDINGSUpdated for the 2024 Ontario Building Code

9.16.2.1.Required Installation of Granular Fill

(1) Except as provided in Sentence (2), not less than 100 mm of coarse clean granular material containing not more than 10% of material that will pass a 4 mm sieve shall be placed beneath floors-on-ground. (See also Subsection 9.13.4. and Note A-9.13.4.) (2) Granular material need not be installed under (a) slabs in garages, carports or accessory buildings, or (b) buildings of industrial occupancy where the nature of the process contained therein permits or requires the use of large openings in the building envelope even during the winter.
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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.