Resilience starts with a roof you can trust to protect your building.
Ron Goodman, EPDM product manager for Carlisle SynTec Systems, and BUILDINGS editor-in-chief Janelle Penny discuss EPDM’s resistance against weathering, heat damage and hail.
Keep listening to this series. Here are #2: Roof Gardens and #3: Alternative Attachment Methods
*This podcast was created in partnership with Carlisle SynTec Systems.
Read the transcript below:
Janelle Penny: Hi. This is Janelle Penny, I’m the editor-in-chief of BUILDINGS. And I’m here with Ron Goodman. He’s the marketing manager for EPDM Roofing Systems with Carlisle.
Today, we’re going to be talking a little bit more in depth about EPDM. So, Ron, why would someone specify EPDM for their roof?
Ron Goodman: Well, one of the things is that EPDM offers time-tested history of performance. We’ve had this product on the market for 58 years now. And it provides superior flexibility, elongation as you would expect with a rubber-based product. Rubber roofing is another term for EPDM roofing.
One of the novel features is it provides excellent UV and hail damage resistance. It’s one of the things that we use on the majority of our own buildings due to the value that it brings to the table.
And it’s definitely in sync with your sustainability and resiliency type goals that many building owners are trying to comply with.
In fact, all of the new buildings that we’ve built in the last five years, including our state-of-the-art technology and education center, our research and innovation center and all the ring roofing of our existing facilities have gone with a fully adhered EPDM roofing system.
Janelle: Great. So, you mentioned hail damage. What makes EPDM in particular resistant to hail?
Ron: EPDM rubber remains flexible and pliable throughout its long life cycle in contrast to other materials that tend to get more brittle with age. Once they lose some of their flexibility, they’re more prone to be fractured or cracked from hail impact.
One thing [is] that most materials start out being flexible and pliable when they’re brand new. However, as they age, the UV and heat exposure tends to make them more brittle, and specifically your asphalt-based products and the plastic-based products. They lose some of that flexibility, so when the hail impacts those membranes, it tends to either fracture them or damage them to the point that they have to be replaced.
In fact, we replaced our own plastic-based roof on one of our facilities in Texas that was hit by hail, and we replaced it with our fleece-backed EPDM product, which is like the gold standard with regards to hail damage.
Janelle: If it’s able to resist these different types of damage, is that part of the reason why it still looks like new after 20 years on the roof? What goes into that?
Ron: The reason why EPDM still looks good even after 20 or 30 years on the roof, it’s the cross-link nature of the EPDM polymer chemistry. It’s really the backbone of the weatherability and the long-term heat resistance.
For example, your thermal plastic-based roofing products or your asphalt-based products, the molecular bonds are not cross linked and therefore, they’re more prone to heat degradation over time. This is why they’re mainly sold in light, reflective colors because they’re trying to keep the heat resistance or heat exposure down on those membranes so that they would last longer.
Janelle: Great. So, now speaking of the product chemistry, are there different colors that are available?
Ron: Yes. EPDM rubber is primarily sold in dark gray or black color. That’s the lion’s share of the business. But it’s also able to be manufactured in white as well. So, we have white and black available.
What we found is in your heating dominated central and northern climates in the U.S., it’s best to use the dark colored membrane for energy efficiency and to help reduce snow accumulation on the roof.
Your white or reflective membranes are best used in the very warm, southern markets that are cooling dominated climates for energy efficiency. And then you typically don’t have to worry about heavy snow loads or anything like that or frost dew or ice that form on the membrane that can be kind of slippery to deal with when you have maintenance workers going up on the roof.
So, generally we follow that same rule ourselves on our own buildings in central and northern climates, we’ve been going with the dark colored EPDM to cut down on our heating energy consumption. And then in the south, we go with the lighter colored white EPDM or white TPO, PVC to basically cut down on your air conditioning costs.
Janelle: Makes sense. What else should we know about EPDM? Are there other defining features that it brings to the table?
Ron: Certainly. One of the main ones is not all 60-mil membranes are created equal. 60-mil single ply membranes are the lion’s share of the business. But they’re not all created the same.
Standard EPDM features a full thickness of 60-mils of cross-linked weathering material, whereas your thermal plastic membranes, they have to be internally reinforced with either a polyester or a glass scrim. And they typically only have 20-24-mils of weathering material over top of that reinforcing scrim.
So, once the membrane wears down to the reinforcing scrim, the membrane begins to take on water, and eventually leads to leaks that are difficult to repair.
Black EPDM grooves particularly look great in the rain. So, if it rains out, the black rubber, it almost looks like a wetsuit on your building. So, it’s a fairly appealing from that standpoint.
They typically don’t show the dirt accumulation like you have with the white or reflective grooves. It doesn’t take much time.
They look great when they’re brand new, but over time, they collect dirt and many times, people have to go up and power wash them off to keep them looking nice.
Janelle: Interesting. Is there somewhere we can learn more about this?
Ron: Yeah, absolutely. The Carlisle Syntec website has a resource page for EPDM and it’s a great way to go in and learn more about it. There are tons of articles that have been written about EPDM, the different attributes that we’ve talked about. And a lot of good information on the different system types, so how you install the membrane on the roof.
Janelle: Well, thank you everyone for listening. And Ron, thank you so much for joining me today.
Ron: Thanks. And have a great day.
Janelle: Thank you. This has been Janelle Penny, editor-in-chief of BUILDINGS and Ron Goodman, signing off.