EPDM basics

By Emma Peterson. 

Dive into the world of EPDM roofing with Kevin Roepe! 

Kevin Roepe is the EPDM (ethylene propylene diene monomer) manager at Johns Manville. For this Lunch and Learn, he stopped by The Coffee Shops™ to chat with Karen Edwards about what EPDM is, how it’s evolved over time and where it fits into the modern commercial roofing market.  

He opened the conversation by explaining the basics – what EPDM is. He shared, “EPDM is a rubber, but it's not a natural rubber, it's a synthetic rubber. EPDM is commonly referred to as a thermoset, which is different than the other single-ply membranes, which are thermoplastics. A thermoset refers to the chemical cross linkage of polymers that occur during the manufacturing process, and that is what really sets it apart from those other single-ply membranes that are on the market.” 

EPDM is made by combining a unique EPDM polymer with a variety of processing aids, stabilizers, fire retardants and carbon black that gives it the classic EPDM black color (as well as UV resistance). EPDM was first made back in the 1960s, just a few years after the first EPDM polymer was synthesized.   

On the roof, EPDM has historically been popular as an alternative to built-up and asphalt roofing. That popularity has carried through to this day. Kevin explained, “Through the early 2000s, EPDM continued to be one of the premier choices for roofing membranes. And over the decades since then, we've seen many advancements in EPDM including improvements in the adhesives and butyl tapes that are used to secure the membrane to the roof and to create the watertight seals that are so critical to the longevity of the roof.”  

And we continue to see manufacturers innovate and improve EPDM through reformulations (making EPDM with different compounds for better performance). Kevin shared some of what Johns Manville is working on, saying, “We have an entire team of engineers and scientists who are dedicated to improving our EPDM products. Whether it be through different manufacturing techniques or through different raw material mixtures, we continue to research ways to make this product better so that we can provide high quality roofing material for the market.” 

Read the transcript or Listen to the episode to learn more about EPDM and how it is used in the roofing industry.