Interlock® designs and manufactures premium interlocking aluminum metal roofing systems — installed by certified local installers across the United States and Canada since 1998. Every roof features the Alunar® Coating System, UL 2218 Class 4 impact resistance, and a transferable 50-year limited warranty — with a Class A fire rating available. Energy-efficient colors with 0.84 thermal emissivity. Cool Roof IR-reflective pigments in the Alunar® coating reflect heat asphalt absorbs — cutting attic temperatures and summer cooling costs by up to 25%.