The Ontario Building Code | Face Sealed Cladding
9.27.3.6. Face Sealed Cladding
(1) Sheathing membrane is permitted to be omitted beneath cladding when the joints in the cladding are formed to effectively prevent the passage of wind and rain in conformance with Sentence (2) or (3), as applicable.
(2) Cladding consisting of sheets of plywood, hardboard, OSB, waferboard or fibre cement is considered to meet the requirements of Sentence (1), provided the cladding is applied so that,
(a) all edges are directly supported by framing,
(b) the vertical joints between adjacent sheets are sealed and,
(i) covered with battens,
(ii) shiplapped, or
(iii) otherwise matched to provide weathertight joints, and
(c) the horizontal joints between adjacent sheets are sealed and,
(i) shiplapped, or
(ii) otherwise matched to provide weathertight joints.
(3) Metal siding consisting of sheets of metal is considered to meet the requirements of Sentence (1) where the joints between sheets are of the locked-seam type.
In Plain Language
Face-sealed cladding, a system relying entirely on sealed joints at the cladding surface rather than a drained cavity, must meet the specific requirements set out in this article.
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.