The Ontario Building Code | Drainage
9.18.5.1. drainage
(1) Except where it can be shown to be unnecessary, the ingress of water into a crawl space shall be controlled by grading or drainage.
(2) drainage of foundation walls shall conform to Article 9.14.2.1.
(3) drainage of the ground cover or floor-on-ground in the crawl space shall conform to Subsection 9.16.3.
(4) Drains shall conform to Section 9.14.
9.18.6. Ground Cover
In Plain Language
Crawl spaces need drainage as set out in this article, managing groundwater or moisture that could otherwise accumulate in this low, enclosed area.
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.