The Ontario Building Code | Control of Water Ingress
9.16.3.1. Control of Water Ingress
(1) Except as provided in Article 9.16.3.2. or where it can be shown to be unnecessary, ingress of water underneath a floor-on-ground shall be prevented by grading or drainage.
In Plain Language
Water ingress into a floor-on-ground must be controlled as set out in this article, addressing moisture that could otherwise seep up through or around the slab.
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.