The Ontario Building Code | Joints
9.27.6.3. Joints
(1) Lumber siding shall prevent water from entering at the joints by the use of lapped or matched joints or by vertical wood battens.
(2) Siding shall overlap not less than 1 mm per 16 mm width of lumber, but not less than,
(a) 9.5 mm for matched siding,
(b) 25 mm for lapped bevel siding, or
(c) 12 mm for vertical battens.
9.27.7. wood Shingles and Shakes
In Plain Language
Joints in this cladding material must be constructed as set out in this article, ensuring proper overlap or sealing to shed water.
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.