Throughout the history of construction, builders and property owners have not had many...Read More
First off, let’s define what a single ply membrane roof is and where it is used. Single ply membrane roofs are sheets of rubber or other synthetics that can be ballasted or chemically adhered to insulation to create a layer of protection for your commercial facility. Single ply membrane roofs are used on flat or near flat roofs, typically on commercial buildings.
There are 3 main types of single ply membrane roofs. They are EPDM, TPO and PVC. Each material has its own sets of pros and cons. To make an informed decision, we will go over the traits that each material possesses and the weaknesses that you will want to know about.
EPDM, commonly known as a “rubber roof”, stands for ethylene propylene diene monomer and gets its name from the chemicals (monomers) that are mixed in various proportions to form it. It is most used on low-sloped or flat roofs, typically on commercial buildings. However, it is also used on residential structures such as car ports and patio roofs.
EPDM is manufactured in large sheets or rolls; it is quick and easy to install. This is one of the advantages of EDPM roofing, the reduced installation cost. At approximately $0.80/square foot, EPDM is one of the most inexpensive roofing materials around.
EPDM roofing membrane is very lightweight, so the roof deck will not need any reinforcement. In fact, one of the most efficient ways to install EPDM on a roof is to simply strip everything off the roof, apply an adhesive, then roll out the membrane. Because there are few seams, leaks are rare (As long as the installer follows the manufacturer’s directions) and a good quality EPDM can last 20+ years.
Contractors have the option of how they will install the material. In addition to using adhesive to attach the material to the roof, there are also fasteners that can be used to anchor it in difficult to reach areas. It can also be ballasted with stone, which can help improve its appearance. Check out our blog on how to adhere EPDM to EPDM here.
TPO, which stands for Thermoplastic Polyolefin is possibly the fastest growing commercial roofing system on the market. It is made up of a single layer of synthetics and reinforcing scrim that can be used to cover flat and semi-flat roofs. The name is a bit misleading, because rather than being plastic, TPO is one of a few different types of rubber, usually a blend of polypropylene and ethylene-propylene rubber.
The main advantage of TPO is that it is typically the lowest material cost for single ply membrane roofs, costing less than EPDM and other types of rolled rubber roofing. The next advantage to point out is the color. TPO typically comes in white on top, which can help reflect the sun’s light and stop heat buildup within the building.
Other positives to TPO membrane are that it offers choices as to how it can be installed. It can be attached with adhesives or fastened directly to the roof deck. It can also be heat welded in places around chimneys and other protrusions. Check out our blog on how to hand weld a TPO seam here.
Finally, TPO resists corrosion and breaks down upon contact with numerous materials. It also does not promote mildew or algae growth and does not require pressure washing. Because of these traits, it makes the material even easier to care for during the annual checkup.
PVC, which stands for polyvinyl chloride is another single ply membraned roofing solution used on flat and semi flat commercial buildings. It is made from a lower percentage of oil and petroleum than TPO or EPDM. As a cool roof membrane, it carriers both Energy Star and Cool Roof ratings.
PVC is surprisingly strong, which is shown in the breaking strength which is at least 350 pounds per square inch – far above the minimum breaking strength required by the ASTM, which is 200 pounds per square inch.
Because PVC is so strong and stable, it can be installed by heat welding the seams, as opposed to other membranes that require adhesive or utilize a taped seam. This installation method allows a PVC roof to expand and contract with a building. PVC can also be sealed with solvent welding and attached to metal flashing and other components with adhesives.
As each membrane has its own unique pros and cons, this list should give you an idea of what traits you are looking for in your roof and help narrow in on the best choice for you. EPDM is a low-cost material however it can be more prone to damage and other mold/mildew build up and it is not the best roof to look at. TPO is a low-cost choice as well and reflects sun rays and heat to keep the building more energy efficient. TPO is a newer product to the market and the jury is still out to see if it can hold up for similar durations compared to PVC and EPDM. PVC is the highest price point of the three single ply membrane roofs we discussed but it is also a proven roof system that is strong, durable, and eco-friendly.
At Clearline Technologies, we have decades of experience in designing and manufacturing rooftop pipe supports that will not only do the job intended, but also outlast the roof that they are being installed on. From roller supports to crossovers and rooftop walkways, our team can work with you to design the perfect system for you. Check out our full line of supports below or give us a call at 866-444-0009.