Single-ply membranes are the most cost effective systems to cover large areas of roof. This fact alone makes them the preferred choice of “big box” retailers. These products are the lightest roof coverings and are usually loose laid with ballast, mechanically attached or adhered to the roof deck. These products, rubber (EPDM) or vinyl (TPO & PVC) are tough and light. The manufacturer’s warranty is typically for ten (10) years.