Who is the biggest roofing company in Canada?

The biggest roofing company in Canada is debated, but several large companies dominate Canadian roofing market, with biggest by revenue and scale being companies like IKO Industries, which is Canadian-owned roofing manufacturer based in Toronto, Ontario, founded in 1951, producing asphalt shingles, roofing membranes, and insulation, with plants across Canada and US, and annual revenue over 1 billion dollars, making it largest Canadian-owned roofing manufacturer. Other big roofing companies in Canada include BP Building Products, which is Canadian shingle manufacturer owned by Saint-Gobain, based in LaSalle, Quebec, making asphalt shingles like Mystique and Manoir, with large market share in Canada. Johns Manville has roofing division with plant in Canada but is American. For roofing contractors, biggest roofing contractor companies include Flynn Group of Companies, based in Mississauga, Ontario, which is largest commercial roofing contractor in North America with revenue over 1 billion and operations across Canada and US, doing large commercial and industrial roofing projects. In terms of shingle manufacturing, IKO and BP are biggest Canadian manufacturers, while US companies like GAF, Owens Corning, and CertainTeed also sell large volumes in Canada. So biggest roofing company in Canada by manufacturing is IKO Industries as Canadian-owned largest shingle manufacturer, and biggest roofing contractor is Flynn Group, both based in Ontario, serving residential and commercial roofing across Canada.