The Ontario Building Code | Orientation of Studs
9.23.10.3. Orientation of studs
(1) Except as permitted in Sentences (2) and (3), all studs shall be placed at right angles to the wall face.
(2) studs on the flat are permitted to be used in gable ends of roofs that contain only unfinished space or in non-loadbearing interior walls within the limits described in Article 9.23.10.1.
(3) wall studs that support only a load from an attic not accessible by a stairway are permitted to be placed on the flat within the limits permitted in Article 9.23.10.1. provided,
(a) the studs are clad on at least one side with plywood, OSB or waferboard sheathing fastened to the face of the studs with a structural adhesive, and
(b) the portion of the roof supported by the studs does not exceed 2.1 m in width.
In Plain Language
Studs must be oriented as set out in this article, ensuring their strongest dimension faces the direction of the load they're designed to carry.
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.