Single ply membrane is the most widely used roofing product being installed in the United States on flat and low slope roofs. Single ply membranes are available in many types of materials, including EPDM (synthetic rubber), PVC and TPO. Most single ply membrane roofs are easy to maintain and repair. A manufacturer's warranty, which provides up to a lifetime of coverage, is a valuable option available on many single ply membrane roof systems. http://www.amcoroof.com/services/singleplyroofing.php