Ontario Building Code - Section 832

9.17.4.1. 2024 Building Code Compendium 122 Division B – Part 9 (2) Except as provided in Article 9.35.4.2., columns shall be not less than 184 mm for round columns and 140 mm by 140 mm for rectangular columns, unless calculations are provided to show that lesser sizes are adequate. 9.17.4.2. Materials (1) Wood columns shall be either solid, glued-laminated or built-up. (2) Built-up columns shall consist of not less than 38 mm thick full-length members (a) bolted together with not less than 9.52 mm diam bolts spaced not more than 450 mm o.c., or (b) nailed together with not less than 76 mm nails spaced not more than 300 mm o.c. (3) Glued-laminated columns shall conform to Section 4.3. 9.17.4.3. Columns in Contact With Concrete (1) Wood columns shall be separated from concrete in contact with the ground by 0.05 mm polyethylene film or Type S roll roofing. 9.17.4.4. Wood Column Termite Protection (1) Where termites are known to exist, exterior wood columns, such as porch supports, shall be (a) pressure-treated with a chemical that is toxic to such termites, in accordance with Article 9.3.2.9., or (b) supported on non-cellulosic material extending not less than 150 mm above the finished ground and shall be located not less than 50 mm from the exterior wall of an adjacent building. 9.17.5. Unit Masonry Columns 9.17.5.1. Materials (1) Unit masonry columns shall be built of masonry units (a) conforming to CSA A165.1, “Concrete block masonry units,” and (b) having a compressive strength over the net area of the block of not less than 15 MPa. 9.17.5.2. Sizes (1) Unit masonry columns shall be not less than 290 mm by 290 mm or 240 mm by 380 mm in size. 9.17.6. Solid Concrete Columns 9.17.6.1. Materials (1) Concrete shall conform to Section 9.3. 9.17.6.2. Sizes (1) Concrete columns shall be not less than 200 mm by 200 mm for rectangular columns and 230 mm diam for circular columns.