Code Library › Volume 1 › Section 9.12 — Excavation
PART 9 — HOUSING AND SMALL BUILDINGSUpdated for the 2024 Ontario Building Code

9.12.3.3.Deleterious Debris and Boulders

(1) Backfill that is within 600 mm of the foundation shall be free of deleterious debris and boulders larger than 250 mm diam. (See Note A-9.12.3.3.(1)) (2) Except as permitted in Sentence (3), backfill shall not contain pyritic material or material that is susceptible to ice lensing in concentrations that will damage the building to a degree that would adversely affect its stability or the performance of assemblies separating dissimilar environments. (See Note A-9.4.4.4.(1)) (3) Backfill with material of any concentration that is susceptible to ice lensing is permitted where foundation walls are (a) cast-in-place concrete, (b) concrete block insulated on the exterior, or (c) concrete block protected from the backfill by a material that serves as a slip plane. (See Note A-9.4.4.4.(1))
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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.