The Ontario Building Code | Materials

9.29.5.2. Materials

(1) gypsum products shall conform to,

(a) CAN/CSA-A82.27-M, "gypsum Board",

(b) ASTM C1178 / C1178M, "Coated glass Mat water-Resistant gypsum Backing panel", or

(c) ASTM C1396 / C1396M, "gypsum Board".