The Ontario Building Code | Material Standards
9.27.8.1. Material Standards
(1) Plywood cladding shall be exterior type conforming to,
(a) CSA O115-M, "Hardwood and Decorative Plywood",
(b) CSA O121, "Douglas Fir Plywood",
(c) CSA O151, "Canadian Softwood Plywood", or
(d) CSA O153-M, "Poplar Plywood".