The Ontario Building Code | Size of Wall Plates

9.23.11.1. Size of wall Plates

(1) Except as provided in Sentence (2), wall plates shall be,

(a) not less than 38 mm thick, and

(b) not less than the required width of the wall studs.

(2) In non-loadbearing walls and in loadbearingwalls where the studs are located directly over framing members, the bottom wall plate may be 19 mm thick.