Membrane roofing is used on flat or low sloped roofs, since conventional shingles only work on sloped roofs. One type of flat roofing membrane is called PVC or polyvinyl chloride, and it has been commonly used since the 1960s.
PVC roofing is one kind of single ply roofing, which means it consists of one layer manufactured in a factory. A PVC roofing membrane is made of thick, flexible UV-resistant thermoplastic material; it may also contain polyester or fiberglass, resins, pigments, plasticizers and other chemicals. The thickness of the roofing membrane varies by manufacturer.
Versatility of PVC Roofing Although white is a common color since it reflects the sun’s heat, different colors are available. Lighter colors like tan, grey or cream are preferred, and some newer types of PVC roofing contain reflective elements and are also Energy Star or Cool Roof rated. Some brands of PVC roofing can be customized with colors or logos. Some brands have a design which looks like conventional shingles from a distance.
PVC roofing can be made to fit nearly any flat roof shape, and is considered a fire safe material. This type of prefabricated flat roofing material is also inexpensive and has good general weather resistance. However, it is normally not used in areas with heavy rains or snow. PVC roofing is also may become brittle in very cold weather. Most PVC roofing membranes are designed to last about 15 to 20 years, although some premium products may have longer warranties.
Some PVC membranes come in panels, while others are adhered to the roof deck, and other others held down by stone or concrete. Some brands of PVC roofing are fleeced cushioned, which allows the membrane to be installed on rough substrates. Many types of PVC membranes are hot welded or fused together to make waterproof seams. Specialized welding equipment is used to join the roofing components together.
Installing and maintaining flat roofing is very different than installing standard asphalt shingles. The longevity of PVC roofing often depends on the skill of the installer and the quality of the seams. Homeowners should choose an experienced roofer who has worked with PVC roofing extensively. All PVC roofing should also be inspected every 6 months so any potential problems can be quickly fixed.