Hot-air welding

A factory-manufactured polymeric waterproofing sheet, typically EPDM, TPO or PVC, installed in a single layer and joined at laps by welding, adhesive or tape. Single-ply systems may be mechanically fastened, fully adhered or ballasted, and are widely used on flat and low-pitched roofs.

Thermoplastic polyolefin, a polymer blend based on polypropylene and ethylene propylene rubber, used as a heat-weldable single-ply roofing membrane. Being thermoplastic, seams are joined by hot-air welding rather than adhesive, and the material contains no plasticisers. Related grades are used for automotive interior and exterior components.

A single-ply roofing and waterproofing sheet based on plasticised polyvinyl chloride, usually reinforced with a polyester or glass fibre scrim and joined by hot-air welded seams. PVC membranes are flexible and easy to detail, though plasticiser migration and incompatibility with bitumen and polystyrene must be addressed in design, typically with separation layers.

A polymer that softens when heated and hardens again on cooling without chemical change, so it can be reshaped, welded or recycled. Thermoplastics range from commodity materials such as polypropylene and PVC to high-performance matrices such as PEEK used in advanced composites.