The Ontario Building Code | Columns in Contact with Concrete
9.17.4.3. columns in Contact with Concrete
(1) wood columns shall be separated from concrete in contact with the ground by 0.05 mm polyethylene film or Type S roll roofing.
In Plain Language
Wood columns in contact with concrete need specific protection as set out in this article, since direct wood-to-concrete contact can wick moisture into the wood and promote decay.
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.