burning bitumen tar floors, waterproofing the floor and roof, high temperature construction work by contractor

burning bitumen tar floors waterproofing 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 dof fire heat hot hydroisolation installing insulation laborer laying material melt membrane roll torching waterproof