EPDM Roofing Deteriorates from Harmful UV Rays – Watch Video


EPDM Roofing Deterioration Stems from UV Exposure

An EPDM roofing problem on a residence in Greenwich, Connecticut stemmed from the prolonged exposure to harmful ultraviolet rays. We found that the single ply EPDM rubber was shredded in a tight corner, next to a chimney, causing the roof to leak.

Over time, the combination of direct sunlight, and the reflection from the chimney caused a concentration of extreme ultraviolet light exposure to that particular area of EPDM rubber. Even though this is an example in the extreme, we saw that the rest of the roof had been similarly affected, showing brittleness and shrinkage.

This will be a costly ongoing roofing repair problem if the homeowner continues to use EPDM as a repair solution. We recommend that this roof be replaced with a 2 ply Modified Bitumen Rubber Roof System that has embedded ceramic granules as protection against harmful UV rays.

Harmful UV Rays Deteriorate EPDM – Watch Video

EPDM Roofing Accounts for 1/3 of All Flat Roofs in the US

EPDM roofing accounts for 1/3 of all flat roofs installed in the US, despite inherent problems of the rubber since its inception in the 1960s. Most roofing contractors will install it and architects will specify it in their designs because it is easy to install and is dependable for the first 8-10 years.

Although EPDM roofing is widely used by professionals, it is important for their clients to know of what the rubber is comprised. An EPDM roofing system has inherent problems, however, most professionals use estimates and tactical salesmanship to promote EPDM as an acceptable roofing solution, even when there are other roofing systems that are more superior.

This doesn’t mean professionals are being dishonest about the products they use, rather, it is a roofing system that they are most familiar with since becoming the industry standard in the 1960s.

At Commercial Roof USA, we provide our clients with a 2 Ply Modified Bitumen Torch Down Roofing System that has built-in UV ray protection, and a 40 year warranty with every installation.

EPDM Roofing Problems in Climatic Conditions

EPDM roofing problems in climatic conditions prove to cause the biggest reason for multiple repairs and eventually a roof’s replacement. These membranes are manufactured in different thicknesses of 45, 60, and 90 Mil., however, 45 Mil. has been used as the industry standard. It is the thinnest rubber of the three options, and can succumb to the careless removal of snow and ice and the constant exposure to sun. This can increase the likelihood that the wear and tear will compromise the membrane with leaks.

We, at Commercial Roof USA, recommend the installation of the 2 Ply Modified Bitumen Torch Down Roofing System as a roofing solution. This membrane is 5 times thicker than an EPDM membrane, and has embedded ceramic granules that protect it from UV ray degradation.

EPDM Roofing - This area of the roof was destroyed by harmful UV exposure.

 EPDM Roofing: Flashing Problems 

With the use of EPDM roofing adhesives, flashing problems occur where walls and roofs intersect. Over time, these adhesives degrade from prolonged exposure to harmful UV rays, because the heat that penetrates the thin membrane, causes premature separation from the flashing.

With the use of the Modified Bitumen Torch Down Rubber Roofing System, the thicker, 2 ply membrane itself, is stabilized with embedded ceramic granules, that are used to prevent UV ray degradation, which protects the transition to the flashing.


EPDM Rubber is Vulnerable

EPDM rubber membranes are vulnerable to the effects of foot traffic. Because work crews service rooftop units, for various reasons, protective mats are essential to protect the thin membrane from being punctured, however, the mats do not cover the work areas adequately. During services and repairs to units, screws, nails, and other sharp objects are unintentionally dropped and left behind. Over time, these sharp objects will be stepped on causing punctures to the thin membrane.

EPDM Roofing Problems - This image shows many repair patches where adhesives have failed due to harmful UV rays.

 EPDM Roofing: Inadequate Seam Caulking

When you watch the next video, you will notice that there is a lap sealer (caulking bead) applied to all seams. This is part of the initial installation process of EPDM roofing. The lap sealant is needed, because the adhesives used to bond the seams, do not provide a water-tight seal. Over time, this thin bead of lap sealer dries up and peels away, causing leaks and compromising the integrity of the entire roof. It’s important to replace the lap sealant every 4 -5 years to properly maintain a single ply EPDM roofing system.


Single Ply EPDM roofing has numerous problems. Once the membrane is compromised, it is subjected to multiple repairs and maintenance. A 2 Ply Modified Bitumen Torch Down Roofing System should be considered when evaluating a permanent solution to these problems.

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