What Is a PVC MEMBRANE?
In the single-ply roofing market, PVC roofing membranes offer an impressive set of advantages. Among the most notable benefits are strength, durability, and resistance to moisture, wind, fire, and chemicals.
PVC membranes contain a base resin modified with plasticizers and UV stabilizers, reinforced with fiberglass non-woven mats or polyester-woven scrims.
PVC membranes are lighter in weight than some other roofing systems. In a re-roof situation, PVC roof membranes typically add very little weight to an existing structure and often go directly over the existing system. This avoids costly tear-offs, meaning no asphalts, felts or other old roof materials go into landfills.
PVC is inherently flame resistant and will not sustain a flame when the fire source is removed. High flame resistance can make it easier for PVC roofing systems to attain Class-A fire ratings than for other roofing systems. Combustion, especially incomplete combustion, is a source of many environmental toxins. A roof membrane that does not burn is less likely than a flammable roofing material to emit potentially harmful substances.
PVC has chemical resistance; it does not absorb or weakened from oils and grease. This means that PVC is the preferred membrane for restaurants and other buildings that have grease traps on the roof.
PVC is a reflective white membrane that will keep your facility cool during the summer, and the PVC sealing properties will make it easier to keep the building warm in the winter.
What is a TPO MEMBRANE?
TPO membranes were introduced to the roofing market in the early 1990’s as an economical and efficient alternative to replace the PVC membrane.
TPO is single ply and consists of a thermoplastic polyolefin membrane, which is made from three layers, a TPO polymer base, a polyester-reinforced fabric center (scrim) and a thermoplastic polyolefin compounded top ply.
TPO membranes are very durable and can make your roof highly resistant to dirt and debris. TPO is also a very flexible material, which makes it resistant to tears, punctures, and impact damage. This flexibility will also translate to a roof that will hold its shape as the rest of the building settles. TPO is available in thicker membranes, which offer even more protection from the elements and from impact damage.
Aside from being the most affordable weather-resistant roofing option, a TPO membrane is also very environmentally friendly. The reflective membrane will make it easier to keep your facility cool during the summer, and the TPO sealing properties will make it easier to keep the building warm in the winter. TPO is also 100 percent recyclable, so you won’t have to worry about the membrane taking up space in a landfill when it comes time to install a new roof.
EPDM (ethylene propylene diene terpolymer) has been a popular rubber roof roofing material. EPDM membrane roofs are lightweight and are more durable than older flat roof systems like BUR and Modified but can be less durable to punctures than modern PVC membranes. EPDM membranes share with PVC the advantage of high recyclability after the useful life of the roof has been exhausted. The naturally dark color of rubber roofs makes them prone to absorbing heat and, in some circumstances, may require a cool white roof coating.
BUILT-UP ROOF (BUR)
Built-up roofs are comprised of hot tar and gravel. They are one of the most affordable flat roof systems. They are typically constructed of three or more layers of waterproof ply sheets which are sandwiched between layers of hot tar.
Modified bitumen as an upgrade to traditional asphalt roofs.
Introduced to the U.S. in the mid-1970s, modified bitumen membranes are roofing sheets made of asphalt that has been modified with either rubber (SBS) or plastic (APP) that offer greater stretch and flexibility. Like BUR, modified bitumen is installed in multiple plies, typically up to 3. Modified bitumen can also serve as the cap sheet of a BUR roofing system.
Metal roofs consist of steel or aluminum panels fastened to the building structure. One of the biggest selling points is metal’s longevity. When installed properly, a metal roof can far outlive the building that it is installed on. The downfall is these roofs are very susceptible to rust, corrosion, wind, and thermal shock which loosens the fasteners over time.