Burning tar bitumen floors to waterproof floor and roof, flaming sheet layers with propane gas burner blowtorch, isolation on production site

burning tar bitumen floors waterproof floor roof high temperature construction contractor flaming roofing sheet layer propane gas burner worker torch welding burns blowtorch flames construction site burn flame bituminous black builder building close up hydroinsulation detail fire heat hot hydroisolation installing insulation laborer laying material melt membrane torching bitumen sheet bitumen roofing coating