The Ontario Building Code | Mansard Style Roofs
9.23.16.6. Mansard Style Roofs
(1) Where the bottom portions of mansard style roofs are vented, the vertical framing members behind the sloping portions shall be considered on the same basis as exterior wall studs and shall conform to the appropriate requirements in Articles 9.27.3.2. to 9.27.3.6.
Section 9.24. Sheet Steel stud wall Framing
9.24.1. General
In Plain Language
Mansard style roofs have specific sheathing requirements set out in this article, addressing their distinctive steep-then-shallow roof geometry.
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.