The Ontario Building Code | Required Sealants
9.27.4.1. Required Sealants
(1) Sealant shall be provided where required to prevent the entry of water into the structure.
(2) Sealant shall be provided between masonry, siding or stucco and the adjacent door and window frames or trim, including sills unless such locations are completely protected from the entry of rain.
(3) Sealant shall be provided at vertical joints between different cladding materials unless the joint is suitably lapped or flashed to prevent the entry of rain.
In Plain Language
Sealants are required at specific locations in the exterior wall assembly, as set out in this article, sealing joints that flashing alone can't fully address.
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.