The Ontario Building Code | Required Drainage
5.8.1.1. Required drainage
(1) Except where a wall or floor is subject to continuous hydrostatic pressure, or unless it can be shown to be unnecessary, the bottom of every exterior foundationwall and every floor-on-ground shall be provided with drainage.
In Plain Language
Except where a wall or floor faces continuous hydrostatic pressure, or unless drainage can be shown unnecessary, the bottom of every exterior foundation wall and floor-on-ground assembly needs adequate drainage.
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.