Attachment of roofing washer with heat-sealed screw-washer assemblage

摘要

An improved method of attaching a roofing membrane to an underlayment and an improved roofing construction made by the improved method. A screw and a composite roofing washer are used to attach the membrane to the underlayment. The composite roofing washer is an interlocked assemblage of a metal roofing washer and a thermoplastic insert. After the screw has been driven, the thermoplastic insert is heated so as to cause some of the material of the thermoplastic insert to flow over the head of the screw, thereby to heat-seal the screw to the thermoplastic insert. The thermoplastic insert may be so heated when the roofing membrane is welded to another like membrane at an overlapped seam.