Polk’s Top 7 Steps to Maintain a Rubber RV Roof

Mark Polk, motorhome and motor coach maintenance expertBy Mark Polk
RV Education 101

About 20 years ago, RV manufacturers began using rubber roofing membrane on RV roofs as opposed to other roof coverings such as aluminum. Among the reasons for the industry's shift to rubber roofing: It was lightweight, seamless, easy to install, easy to maintain, cost-effective, and ozone- and UV-resistant.

The rubber membrane itself will last 20 years or longer, but certain preventive and scheduled maintenance procedures must be followed to maximize the life of a rubber RV roof.

Here are my top 7 steps for a healthy rubber roof.

Step 1: Safety first. You have to get on the roof of the motorhome to clean it properly and inspect it for damage or potential water leaks. Be careful whenever you are working on your RV roof. You can be seriously injured or killed from a fall.

Some RV roofs are more structurally sound than others. Regardless of the roof’s structural integrity, walk on it lightly, and be careful. When cleaning an RV roof, some wet surfaces are extremely slippery. If you aren’t comfortable working on the roof, have the required maintenance and repairs performed by a reputable RV service.

Step 2: The next step is to become familiar with the rubber roofing used in the RV industry. Keep in mind there are other types of roofing materials used, such as vinyl and fiberglass, but this article pertains to rubber roofing. 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).

Often, I get asked how you can distinguish between the two. The best way is to see what your RV owner’s manual says. Normally it will specify the type of rubber membrane used and provide cleaning and maintenance instructions and intervals as well. If you don’t have an owner’s manual or if the manual doesn’t specify the type of roofing used, there are a couple of ways to distinguish between the two.

To help protect against ozone and UV rays, EPDM roofing membrane is designed to oxidize or shed over time. This is not a concern, though, because it probably will shed less than 10 percent of its overall thickness in a 10- to 12-year time period. As a result of the shedding, the tell-tale signs of EPDM rubber are the gray or white streaks that you see on the sides of the RV.

TPO roofing does not oxidize or shed, so there are no gray or white streaks. Another way to distinguish between the two is to see how slippery the rubber surface is when it is wet. EPDM roofing is extremely slippery when it is wet, whereas TPO is not. But regardless of how slippery the surface is, always exercise caution when working on your RV roof!

Step 3: Inspect your rubber roof. I mentioned earlier that the roofing membrane will last 20 years or longer, but that doesn’t mean the sealants and seams will. Any seam on the roof, and any opening cut in the roof, has the potential for a water leak.

When an RV flexes and moves as it travels down the road, it is common for the seams and sealants to move, too. This, along with age, causes sealants to separate and allows a path for water to get through the seams and sealants.

It’s important that you thoroughly inspect the roof seams and sealants on a regular basis. In most cases your warranty is void if these routine inspection intervals are not followed.

Rubber roofing is also prone to tears from things like tree branches, so it’s important to inspect the entire roof, not just the seams and sealants. Your owner’s manual should specify inspection intervals.

Step 4: Use the proper materials to make roof repairs. If you discover a problem during your routine roof inspections it’s important the repairs are properly completed. This includes using the proper sealants and materials for rubber roofing.

I cannot begin to tell you how many times I have seen the wrong types of sealants used on rubber roof surfaces. For example, silicone will not properly adhere to a rubber roof. After it is applied and cures it will peel easily from the rubber surface. Lots of folks make a repair using silicone products and are left with a false sense of security that all is well. This kind of thinking results in expensive-to-repair water damage down the road.

When I work on rubber roofs, depending on the nature of the repair, I use butyl tape and/or Dicor 501 LSW lap sealant. This sealant is compatible with all RV roof surfaces and it is self-leveling and flexible. For a tear in the roof I use a product called EternaBond or a Dicor rubber roof repair kit.

Step 5: Clean your rubber roof. A clean rubber roof is a healthy rubber roof. This is another topic I get asked about a lot. What type of product should I use to clean my rubber roof? How often should I clean my roof? Rubber roofs should be cleaned several times a year and, depending on where you park or store your motorhome, it may need to be cleaned more often.

Most rubber roof manufacturers recommend using a medium bristle brush and a non-abrasive cleaner. For light cleaning, use warm water and a mild detergent like Dawn dishwashing liquid. For more difficult cleaning, there are commercial cleaning products designed specifically for rubber roofing.

Hard-to-clean areas like stubborn stains caused by leaves, sap, mold or mildew may require a second treatment. Use caution to prevent the cleaners from getting on the sides of the RV. Always rinse the sides, front and back of your RV before and after rinsing the roof to prevent cleaners from streaking or damaging the finish on your RV sidewalls.

Regardless of the type of rubber roof you have, NEVER use any cleaners or conditioners that contain petroleum solvents, harsh abrasives or citrus ingredients. These types of cleaners can cause permanent damage to rubber and vinyl surfaces. The first indication of rubber roofing coming in contact with petroleum products is a bubble forming. The thickness of the rubber is compromised and chances are it will never adhere to the roof decking again.

Step 6: Avoid some aftermarket RV rubber roof products. Numerous aftermarket products claim to protect, clean and condition your rubber roof. For the sake of liability, I will not mention any product names, but I will advise you to select products carefully.

Rubber roofs already have built-in ozone and UV protectors, and cleaning a rubber roof is quite simple. You can use household cleaners like Comet and Spic And Span or Dawn dishwashing liquid for most routine cleaning needs. If a stronger cleaner is required for tough stains, make sure to read the ingredients label carefully before purchasing and using the product. Some cleaners work great, others don’t. Remember, do not use cleaners or conditioners that contain petroleum solvents, harsh abrasives or citrus ingredients.

 Step 7: Keep it simple. You can maximize the life of your rubber roof by following these few simple steps: Exercise safety, know the type of roof you have, inspect it, repair it and clean it according to the specified intervals. And, avoid using unnecessary products for your rubber roof.