The Ontario Building Code | Dampproofing
9.13.2.1. Dampproofing
(1) Except as provided in Article 9.13.3.1., where the exterior finished ground level is at a higher elevation than the ground level inside the foundationwalls, exterior surfaces of foundation walls below ground level shall be dampproofed.
(2) Except as provided in Sentence (3) and Article 9.13.3.1., floors-on-ground shall be dampproofed.
(3) floors in garages, floors in unenclosed portions of buildingsand floors installed over granular fill in conformance with Article 9.16.2.1. need not be dampproofed.
(4) Dampproofing in Sentence (1) is not required where the exterior surfaces of foundation walls below ground level are waterproofed.
In Plain Language
Dampproofing, a lighter moisture-resistant treatment for foundation walls, is required under the conditions set out in this article, addressing everyday soil moisture rather than standing water pressure.
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.