Of all the new types of roofing available on the market today, one of the least understood is PVC roofing. PVC is often thought of as plumbing pipes, but this versatile plastic can also be used to very great affect on some types of roofs such as conservatories and flat roofs.
What Is PVC?
PVC stands for polyvinyl chloride, a type of plastic formed through a gaseous reaction of ethylene with oxygen and hydrochloric acid. As a roofing material, the plasticized attributes help lend it a strength that can help make the roof more durable and lower maintenance than similar materials.
PVC Roofing Uses
PVC roofs come in two general types. One is primarily used on flat roofs, while the other is used on conservatories.
PVC Flat Roofing
Like most materials used on flat roofing, PVC comes in a membrane form. This membrane is rolled out onto the roof and adhered to the deck either with adhesives or nails. The addition of the plastics to the membrane helps to make it impervious to punctures and rips that sometimes plague other types of flat roofs. It is also chemical resistant and fairly low maintenance, making it an ideal choice for some types of commercial buildings.
Like asphalt roofing, PVC is usually heat welded at the seams. This is beneficial because seams are the weakest part of a flat roof, the heat welding helps to seal the areas and keep them watertight. A good PVC roof is both lightweight and durable, lasting approximately 20 years, or about the longest lifespan of any flat roof.
The biggest drawback to using PVC roofing on a flat roof is the fact that it cannot interact with asphalt materials in any way. Some flat roofs are made up of a combination of materials, or may have hot asphalt applied on top of the membrane. This cannot be done with PVC roofing, and if asphalt roofing is used in conjunction with PVC, the two areas must be kept separate from one another.
PVC roofing comes in a wide variety of different thicknesses. Unlike some types of flat roofing in this case, thicker is better and often makes the roof more resistant to cracking or splitting.
PVC Conservatory Roofing
PVC conservatory roofs are relatively new. Conservatory roofs were originally made up of at least 74% glass, but recent laws have changed that allow them to be covered with a wide variety of different materials. Because of the structure of the conservatory, however – at least 50% glass – the roof needs to be fairly lightweight in order to be supported without affecting the structure.
PVC roof panels and membranes are both extremely lightweight, making them ideal for conservatory roofs. PVC is a little slower to catch on than other types of conservatory roofing and it can be difficult to find a roofing contractor that can work with it. Most types of PVC roofing used on conservatories are installed in panels that resemble standing-seam roofs. The panels interlock with one another or use fasteners to hold them together. Like most lightweight panel roofs, they need to be attached and ballasted carefully to ensure that they are as durable as possible and do not leak. Installation is everything to this type of panel, so finding a reputable roofing contractor that works with it is the key to a successful roof.
Potential for Future Use
PVC is slow to catch on as a roofing material, mostly because no one has heard of it as it isn’t widely promoted. As more people begin to realize it’s benefits – lightweight, chemically impervious, and difficult to puncture – it may begin to get more use in the future on additional roof types as well.
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