Flat roofing systems are used all over the world for industrial and commercial properties. There are many options for the surfacing of flat roofs such as concrete or masonry. Other options include tar/tar paper coating or membranes. Membranes are usually applied in strips of sheets and have been used as long as 60 years. An alternative that does not come in strips is a custom fit, Duro-Last PVC membrane. This system has been installed in nearly a million roofs, including industrial, commercial and institutional applications.