Single-ply membrane roof systems have been used for decades and are one of the most trusted options for roofing. Despite its common use, many often wonder how single-ply membrane systems are installed and what their advantage is over other membrane options. If these are questions you find yourself thinking about, keep reading to learn everything you need to know about single-ply membrane systems.
The Advantages of Single-Ply Membrane Roofing Systems
Single-ply membranes are either TPO (Thermoplastic Polyolefin) or EPDM (ethylene propylene diene monomer). An EPDM roof is a rubber membrane and it is manufactured in a similar way as TPO membranes but uses different products. The process of adhering the layers together is also different for TPO membranes. EPDM has been around for 60 years and up until the creation of TPO was the only membrane system used. A TPO roof is a thermoplastic membrane that has been manufactured into different layers. Between each layer is scrim and the layers are all bonded together to create a roofing system. TPO has only been around for 20 years and is recently gaining popularity, not making up 60% of roofing membranes. For both TPO and EPDM membranes the thickness used is either 45-mil, 60-mil, or 90-mil. TPO typically uses a white membrane that reflects the sun’s heat and UV rays away from the roof, so you save energy and money.
The EPDM membrane system is often darker which means it will absorb heat. This is most likely the reason for the increase in TPO use in recent years, as ‘green’ living and energy conservation are hot topics. With regards to the installation of single-ply membrane systems, the first step is to prepare the existing roof. The surface needs to be cleaned with all debris removed. A cover board is then laid down on which the membrane will be installed. If you have to do complete roof removal and replacement, strip everything down to the deck, adhere to new insulation, and then the membrane will go over the top of that. The two single-ply membrane systems have different attachment methods. EPDM membranes are mechanically fastened using screws and plates, ballasted with gravel, or fully adhered with strong adhesives. TPO membrane attachment also offers mechanical fastening and adhesives, but there is no option for ballasting with gravel. EPDM installation involves seam tapes to hold seams together while TPO membranes use welders or hot-air guns to fuse seams.
The advantages of the single-ply membrane systems include:
- Class A fire rating
- Moderate costs
- Easy installation
- Proven track record of reliability
Disadvantages of single-ply membranes that are worth considering include:
- Possible loss of tensile strength over years which causes bellowing
- Easily punctured
- UV degradation over time
Single-ply membrane systems can come with a warranty lasting between 5 and 30 years, depending on type and manufacturer. Once warranties expire, your options include adding a new membrane over the existing one or adding an SRM coating to extend the lifespan and warranty.
Even with a warranty, you need to maintain the roof and membrane system to get the longest lifespan. A professional contractor needs to do regular inspections and maintenance, checking the roof for damage, punctures, and wear. For any punctures, the area needs to be cleaned and primed and then covered with a patch that is 3 inches larger than the puncture hole. You will use a hot-air gun for TPO repairs and an adhesive for EPDM repairs. All repairs need to be made right away to prevent serious damage and expensive roof replacement. For any concerns or questions regarding single-ply membrane systems, reach out to us today. We are ready to help with installation, repairs, and regular maintenance to help protect your roof and investment.