Flat roofs are often seen as less attractive than traditional arched or sloped roofing. However, they are also inexpensive to construct, easy to maintain, and can accommodate rooftop air conditioners, solar panels, and other equipment. This makes flat roofing ideal for a wide variety of commercial buildings, including warehouses, retail buildings, and restaurants.
However, if you are constructing a new commercial building with a flat roof, or need to replace the roofing on an existing building, choosing the right roofing material(s) is absolutely vital. Flat roofs are not compatible with many roofing materials commonly used on sloped roofs, so you should familiarize yourself with the more specialized materials used on flat roofs before making any kind of decision.
Which Roofing Materials Are Best For Flat Roofed Commercial Buildings?
Built-Up Roofing (BUR)
Built-up roofing, or BUR, is made from multiple sheets of tough, tear-resistant fiberglass fabric. These layers are sandwiched between layers of hot bitumen and then covered with gravel, river stones, or other solid ballast.
Although it has been in use for decades, built-up roofing has many advantages over more modern alternatives. It is very easy to maintain, can support heavy roof-mounted equipment, and is highly fire-resistant. It is also exceptionally durable, and a well-constructed BUR roof can last for well over 30 years before serious repairs are required.
Unfortunately, built-up roofing is also notorious for being time-consuming and difficult to install, which can raise labor costs on your roofing project. Most types of BUR are also very heavy, and your commercial building may require additional (and expensive) reinforcement to support a replacement BUR roof.
Synthetic Rubber Membrane
Sold under a variety of trade names such as Thermoset, synthetic rubber membrane is a low-cost option ideal for many smaller commercial buildings. Surprisingly durable and very easy to install, synthetic rubber membrane roofing is made from EPDM, a man-made rubber renowned for its excellent resistance to wind, rain, and UV sunlight.
Synthetic rubber roofing is also surprisingly resistant to minor physical damage, such as scuffs and tears. However, it is much more vulnerable to puncturing and should not be used on flat roofs that are overlooked by trees, shingled roofs, or other potential hazards. They also have a tendency to absorb heat, which can raise your building's utility bills — heat-resistant versions are available but cost significantly more.
Visually very similar to synthetic rubber roofing, PVC membrane roofing is made from thermoplastics instead of synthetic rubber, and is much tougher and more durable as a result. The unique properties of PVC allow it to be 'welded' directly to your building's roof using jets of hot air, creating a watertight roof that is almost impervious to leaks. PVC membranes are also more fire-resistant than EPDM membranes.
PVC roofing is also just as quick and easy to install as synthetic rubber roofing and is perfect for pop-up stores and other temporary structures. Unfortunately, all of these advantages come at a cost, and PVC membrane roofing can cost a good deal more than synthetic rubber membrane roofing.
For more information on commercial roofing, reach out to a local roofer.