TPO versus EPDM: which system is better?

Mar 11, 2020
01

One of the most common questions we get is: Which roof system is better, black “Rubber” EPDM or white “Thermoplastic” TPO? Both are similar in price, both come with 15-30 year warranties, both are made by reputable manufacturers, and both are widely installed throughout New England.  So that begs the question, is one roofing material actually better than the other?

Key Differences

In my view, neither roof system is definitively better than the other. However, they do have key differences that may have an impact depending on your building. These differences include:

  • Heat and UV Resistance: When it comes to heat and UV resistance, EPDM is the superior product. As a general rule, EPDM can reach temperatures of around 180 to 200 degrees, whereas TPO can only reach temperatures of around 140 degrees. This can make a difference in buildings that have a high heat output or a lot of dark, high heat surfaces surrounding the building.
  • Grease and Oil Resistance: TPO is far better with food byproducts, such as grease and oil. Grease guards should always be used, and neither system is warranted against grease, but TPO will hold up much better than EPDM in the event of a leakage or fluid backup. 
  • Puncture Resistance: In my view, both products have similar puncture resistance. However, many of the manufacturers are starting to provide puncture resistant warranties on reinforced EPDM roof systems. This can make a big difference on roofs with multiple contractors, tenants, and other foot traffic on the roof, where finding out who made a hole can be more difficult than finding the hole. If puncture resistance is covered in your warranty, it doesn’t matter who made the hole. The manufacturer will pay to patch it.
  • Flashing Technology: TPO roof systems are flashed together using heat welding. This is the best flashing technology available because the bond on a heat weld is as strong as the membrane itself. EPDM has come a long way, especially with self-adhered flashing products, some of which are factory installed on the membrane. However, nothing beats a proper heat weld.
  • Ease of installation and repairs: Self-adhered EPDM flashings are much easier to install than heat welded TPO flashings. Installing a self-adhered detail involves cleaning, installing the primer, waiting for the primer to dry, and then rolling the flashing detail in place. Heat welding requires careful craftsmanship. Overheat TPO and you will burn it. Underheat TPO and it won’t bond properly, causing the flashing detail to pop open. As long as you have a skilled roofing contractor performing your work, they will be able to install either roof system. 
  • Formulations: EPDM, as a rule of thumb, is a far more consistent formula than TPO. While the flashing technology has evolved over time, the EPDM membrane itself has remained largely the same. With TPO, formulations change from time to time, sometimes resulting in premature failures. This is why with either roof system it is important to get a manufacturer’s warranty. If there is a failure in a production run of a product, a manufacturer will have the resources to repair or replace those roofs, where a contractor most likely won’t. Think of it as a product recall. If there is a problem with a particular component, the manufacturer is responsible for providing a proper fix.

Our approach at Chaffee Roofing is to evaluate each building’s unique needs and requirements before recommending a roof system. In a restaurant, for example, TPO is typically the better option due to grease and oil output. On a manufacturing plant that operates at a higher temperature than typical inside the building, EPDM would be a better option. On a strip mall, with multiple different tenants, it’s a toss-up based on current and future use. In our view, neither system is definitively better than the other, it’s more about how your building is used and which roof system is a better match based on the building’s needs.

Call Us

Your roofing project is only as good as the installing company and the product they use. On TPO roof systems, this is especially important since effective welding requires skilled workers.

At Chaffee Roofing we use TPO of the highest quality and our technicians are highly trained. We offer the best service and guarantee all of our work.

Call Chaffee Roofing today for answers to all of your TPO roofing questions.

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One Comment

  1. John Howell sr. retired building inspector ROICC naval air sta. Brunswick, Me. April 22, 2020 at 7:37 pm - Reply

    Getting estimates for epdm/TPO roof Brunswick ME. Conducted 1st. Roof top site visit today w/ manuf rep also on site.

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