Weighing the Pros and Cons of an EPDM Rubber Roof
Is synthetic rubber the best choice for your building’s roof? Ethylene propylene diene monomer, or EPDM, comes in large sheets that reduce seams, which are often weak points in commercial roofing that lead to leaks.
You may be considering EPDM rubber roofing for your commercial building – which can be a great choice. But, EPDM installations are more effective in certain environments than others, so you have to do some research before you commit.
What is an EPDM Rubber Roof?
EPDM single-ply roofing is made of synthetic rubber (elastomeric polymer).
It’s used to protect low slope roofs (it’s also used to make window seals and flexible body parts for cars). EPDM roofing membranes are available in thicknesses of 40 and 60 mils, and in widths from 7 ½ to 50 feet.
Once the rubber is rolled out onto the roof, it can be held down with ballast, or attached to the underlayment with either fasteners or adhesives. Seam tape or bonding adhesive sealant is then added to the seams to create a uniform, waterproof barrier.
There are two colors of EPDM: black EPDM and white.
Black EPDM
Black roofing doesn’t show dirt, and it’s widely available. To achieve the black membrane, carbon black is added, and with black roofing, UV rays are converted into heat.
White EPDM
White roof coatings are applied to EPDM to make them better at reflecting heat. The only downfall is that the white can look dingy over time. Titanium dioxide is what reflects UV rays, making this a great option for energy efficiency.
Where are EPDM Roofing Systems Used?
EPDM is used on roofs with a slope of 2:12 or less – that’s two vertical units for every 12 horizontal units, or two inches of slope for every foot of length.
Unlike most roofing systems, correctly installed EPDM is completely waterproof, so it’s a great choice for roofing that can’t depend on a steep slope for runoff. Ponding can still cause a problem, but it’s more resistant to roof leaks than other roofing materials like shingles. Especially when you apply a silicone coating. Silicone adheres well to EPDM and can greatly improve it’s weather resistance, and it’s lifespan.
The average lifespan of an EPDM rubber roof is between 25 and 30 years with regular maintenance. Of course, your experience may vary, depending on the quality of the installation and your local weather. The average cost of a large commercial roof is around $6-$12 per square foot, including materials, installation, and removal of old roofing material.
While EPDM has low puncture resistance, problems can be mitigated by using thicker roofing sheets and adding ballast to create a protective layer.
EPDM Roof Installation Methods
There are three ways to fit an EPDM roofing system to a building’s roof: adhesives, fasteners, and ballast.
Adhesion
With this method, the sheets of rubber roofing membrane are glued directly to the roof. This is the most durable installation method and the most expensive. It also requires warm weather for the adhesive to cure, limiting when the roof can be installed.
Mechanically Fastened
Screws or plates attach the rubber sheets to the roof decking. This is the most common installation method.
Ballasted
Ballasted EPDM incorporates a layer of pavers or stones that holds down the rubber roofing. The ballast adds another layer of protection from debris and UV light and is the least expensive installation method (but it also has the highest maintenance costs). It’s also important to remember that each square foot of ballast adds several pounds to the roof, which may be more than the building can handle.
EPDM Compared to Other Roofing Options
Different roofing products have their own advantages and makeup. There are two roofing materials that are similar to EPDM: TPO and PVC. All three are extremely popular roofing for commercial buildings.
TPO
Thermoplastic polyolefin (TPO) is made from reinforced thermoplastics and is single-ply, which is cheaper than EPDM. These are usually white roofing systems that reflect UV rays, in turn helping the AC units in the hotter summer months (or in warmer, sunnier climates).
PVC
Polyvinyl chloride (PVC) is strong and durable. It can withstand severe weather, but over time, shrinkage can lead to leaks. It’s also more expensive to install than EPDM. Both TPO and PVC come in smaller rolls than EPDM, which adds more seams in the roof and can increase the potential for leaks.
Asphalt
Commercial asphalt roofs fit into two categories: built-up roofing (BUR), which includes layers of substrate that are adhered with asphalt, or modified bitumen systems (MBS), a modified polymer.
These multi-layer roofs equate to a high degree of UV and fire protection, longer warranties and material options. A drawback includes using an open flame to get the asphalt to adhere and do its job, which can be harmful to your commercial building. You also need to hire an experienced, reputable roofing contractor to complete the work.
Metal
Metal roofing lasts at least twice as long as an EPDM roofing system, however, it’s also much more expensive to install and maintain. Metal also weighs more. This may make the entire roof too heavy for the structure, especially if it’s already loaded down with solar panels and HVAC equipment.
Unfortunately, if you have a steep or complex commercial roof design, EPDM isn’t an optimal choice. But, if you have a flat or low-sloped roof, EPDM is a great option! It’s important to keep in mind that any of the roofing options discussed above should be installed by professional roofers. DIY-type jobs can void any warranties and can also end in serious injury.
Find the Right Roofing Solution with TEMA
Whether you need help discussing EPDM rubber roof options for your flat roof, you’re in need of roof repair or it’s time for a new roof and you’re looking for full commercial roof replacement, TEMA can guide you.
TEMA Roofing Services provides high-quality commercial roofing to customers nationwide. Our design-build services take care of planning and installation, so you work with one single contact for the entire construction process.
Want to take the worry out of your installation? We also offer roof asset management and a convenient online portal, providing inspections, maintenance and repairs through the life of your roof. Contact us today to get a free quote.