The Ontario Building Code | Material Standards

9.23.15.2. Material Standards

(1) wood-based panels used for roof sheathing shall conform to the requirements of,

(a) CSA O121, "Douglas Fir Plywood",

(b) CSA O151, "Canadian Softwood Plywood",

(c) CSA O153-M, "Poplar Plywood",

(d) CSA O325, "Construction Sheathing", or

(e) CSA O437.0, "OSB and Waferboard".