WeatherBond PRO PVC is an advanced-formula, heat-weldable PVC thermoplastic membrane that is designed for long-term weatherability and performance. The physical properties of the membrane are enhanced by a tenacious, weft-inserted polyester fabric that is encapsulated by thick PVC-based top and bottom plies. The smooth surface of the PVC membrane allows for a total-surface fusion and permanent weld, creating a consistent, watertight monolithic roof assembly. PVC can be used in adhered and mechanically fastened systems. The dark gray-colored bottom ply provides a visual confirmation of a proper weld during the lap welding process.