1507.4.3 Material standards.
BC § 1507.4.3
Metal-sheet roof covering systems that incorporate supporting structural members shall be designed in accordance with Chapter 22. Metal-sheet roof coverings installed over structural decking shall comply with Table 1507.4.3(1). The materials used for metal-sheet roof coverings shall be naturally corrosion resistant or provided with corrosion resistance in accordance with the standards and minimum thicknesses shown in Table 1507.4.3(2). Table 1507.4.3(1)Metal Roof Coverings Roof Covering Type Standard Application Rate/Thickness Roof Covering Type Standard Application Rate/Thickness AluminumASTM B 209, 0.024 inch minimum thickness for roll-formed panels and 0.019 inch minimum thickness for press-formed shingles.Aluminum-zinc alloy coated steelASTM A 792 AZ 50Cold-rolled copperASTM B 370 minimum 16 oz./sq. ft. and 12 oz./sq. ft. high yield copper for metal-sheet roof covering systems: 12 oz./sq. ft. for preformed metal shingle systems.Copper16 oz./sq. ft. for metal-sheet roof-covering systems; 12 oz./sq. ft. for pre-formed metal shingle systems.Galvanized steelASTM A 653 G-90 zinc-coated aHard lead2 lbs / sq. ftLead-coated copperASTM B 101Prepainted steelASTM A 755Soft lead3 lbs./sq. ftStainless steelASTM A 240, 300 Series AlloysSteelASTM A 924Terne and terne-coated stainlessTerne coating of 40 lbs. per double base box, field painted where applicable in accordance with manufacturer's instructions.Zinc0.027 inch minimum thickness; 99.995% electrolytic high grade zinc with alloy additives of copper (0.08% - 0.20%), titanium (0.07% - 0.12%) and aluminum (0.015%). For SI: 1 ounce per square foot = 0.305 kg/m 2 , 1 pound per square foot = 4.882 kg/m 2 , 1 inch = 25.4 mm, 1 pound = 0.454 kg. a. For Group U buildings, the minimum coating thickness for ASTM A 653 galvanized steel roofing shall be G-60. Table 1507.4.3(2)Minimum Corrosion Resistance MaterialStandard55% Aluminum-zinc alloy coated steelASTM A 792 AZ 505% Aluminum alloy-coated steelASTM A 875 GF60Aluminum-coated steelASTM A 463 T2 65Galvanized steelASTM A 653 G-90Prepainted steelASTM A 755 a a. Paint systems in accordance with ASTM A 755 shall be applied over steel products with corrosion resistant coatings complying with ASTM A 792, ASTM A 875, ASTM A 463 or ASTM A 653.
