The Ontario Building Code | Required Sheathing
9.23.16.1. Required Sheathing
(1) exterior walls and gable ends shall be sheathed when the exterior cladding requires intermediate fastening between supports or if the exterior cladding requires solid backing.
In Plain Language
Wall sheathing is required over studs, as set out in this article, providing a structural and racking-resistant layer beneath the exterior cladding.
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.