Over the years RV manufacturers used many different types of materials in the construction of RV roofs. Materials like galvanized metal, fiberglass and aluminum were the final layer of protection for the RV roof. Then about 20 years ago the RV industry discovered a new and improved RV roofing product that would change the way RV roofs were finished. The product was a rubber roofing membrane, and it made sense because it was lightweight, seamless, easy to install, easy to maintain, cost-effective, and resistant to ozone and UV rays from the sun.
For the most part there are two types of rubber roofing used in the RV industry: Ethylene Propylene Diene Monomer (EPDM) and Thermal Poly Olefin (TPO). The problem is each type has its own unique characteristics and care and maintenance requirements, but most RV owners don’t know which type of rubber roof they have.
Do I have an EPDM or TPO RV rubber roof?
The best way to determine the type of rubber roof you have is to see what your RV owner’s manual says. Normally it will specify the type of RV rubber roof membrane used on the RV, and it will provide cleaning and maintenance instructions and intervals as well. If you don’t have an RV owner’s manual, or it doesn’t specify the type of roofing used, there are a couple ways to distinguish between the two types of RV rubber roofing.
EPDM RV rubber roof: To help protect against ozone and UV rays EPDM roofing membrane is designed to oxidize or shed over time. It is not a big concern because it will probably shed less than 10% of its overall thickness in a 10 to 12 year time period. As a result of this shedding the tell-tale signs of EPDM rubber roofs are the gray or white streaks you see on the sides of the RV.
TPO RV rubber roof: TPO rubber roofing has a glossy look and does not oxidize or shed, so there are no gray or white streaks noticeable on the sides of your RV.
Still not Sure? Another way to distinguish between the two is to see how slippery the rubber surface is when it is wet. EPDM rubber roofing is extremely slippery when it is wet, whereas TPO is not. Caution: Regardless of how slippery the surface is always exercise caution when working on your RV roof!
Keep in mind we only discussed the two most popular types of rubber roofing used on RVs. There are other products, like vinyl materials, being used on RV roofs. To properly care for and maintain your RV roof it’s important you know what the finished roofing material is made of.
Special Note: Be careful where you get your information on making repairs to your rubber roof. I always see articles where the author says to just put some silicone caulking on the roof to make repairs. EPDM rubber membrane can be damaged by products containing oil or petroleum. Both EPDM and TPO rubber roofing warns against using petroleum solvents, harsh abrasives or citric based products and cleaners.
I personally use Dicor 501 LSW Self-Leveling Sealant for repairs on rubber roofs. This sealant is used in the RV industry by Original Equipment Manufacturers (OEMs) and for aftermarket use. It is compatible with EPDM and TPO rubber products, galvanized metal, aluminum and fiberglass roofs. This dicor product is available at most local RV dealerships.
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