Ontario Building Code - Section 487

2024 Building Code Compendium 4.1.6.16. Division B – Part 4 31 4.1.6.13. Specific Weight of Snow (1) For the purposes of calculating snow loads in drifts, the specific weight of snow, γ, shall be taken as 4.0 kN/m 3 or 0.43S S + 2.2 kN/m 3 , whichever is lesser. 4.1.6.14. Snow Removal (1) Snow removal by mechanical, thermal, manual or other means shall not be used as a rationale to reduce design snow loads. 4.1.6.15. Ice Loading of Structures (1) For lattice structures connected to the building, and other building components or appurtenances involving small width elements subject to significant ice accretion, the weight of ice accretion and the effective area presented to wind shall be as prescribed in CAN/CSA-S37, “Antennas, towers, and antenna-supporting structures.” 4.1.6.16. Roofs with Solar Panels (See Note A-4.1.6.16.) (1) Where solar panels are installed on a roof, the snow loads, S, shall be determined in accordance with Sentences (2) to (6) or with the requirements for roofs without solar panels, whichever produces the most critical effect. (2) For the purposes of this Article, solar panels shall be classified as (a) Parallel Flush, where the panels are installed parallel to the roof surface with their upper surface less than or equal to C b C w S s /γ above the roof surface, (b) Parallel Raised, where the panels are installed parallel to the roof surface with their upper surface greater than C b C w S s /γ above the roof surface, or (c) Tilted, where the panels are installed at an angle to the roof surface with their highest edge greater than C b C w S s /γ above the roof surface. (3) For sloped roofs with solar panels, the snow loads, S, shall be determined in accordance with the requirements for roofs without solar panels, except that the slope factor, C s , shall be (a) taken as 1.0 for roof areas extending upslope from the downslope edge of a panel or array of panels at an angle of 45° from each side edge of the panel or array, and (b) as specified in Sentences 4.1.6.2.(5) to (7) for all other roof areas. (See Note A-4.1.6.16.(3)) (4) For sloped roofs with Parallel Flush solar panels, the snow loads, S, shall be determined in accordance with the requirements for roofs without solar panels, except that (a) C s shall be determined in accordance with Sentence (3), (b) where the gap width, w g , between the panels along the roof slope is greater than or equal to the panel width, w p , along the roof slope, the accumulation factor, C a , shall be taken as (i) 0.0 for the panels, (ii) 2.0 for roof areas within a distance of w p downslope from a downslope panel edge, and (iii) 1.0 for all other roof areas, and (See Note A-4.1.6.16.(4)(b)) (c) where the gap width, w g , between the panels along the roof slope is less than the panel width, w p , along the roof slope, C a shall be taken as (i) 0.0 for panel areas within a distance of w g downslope from an upslope panel edge, (ii) 1.0 for other panel areas, (iii) 2.0 for roof areas in gaps between the panels, and (iv) 1.0 for all other roof areas. (See Note A-4.1.6.16.(4)(c))