“Rubber” (more properly EPDM or TPO) is the most common roof covering material for RVs. Regardless of their seemingly fragile composition, they are fairly robust. Major damage can occur to rubber roofs, with common causes being treefall and lack of maintenance, which tends to lead to water damage. However, most minor damage, such as small holes and tears, can be repaired by most RV owners with little difficulty and few tools. In this article I will describe rubber roof patching using the example of specific damage identified on an RV.

If you have a hole in your rubber roof up to about the size of a silver dollar, you can simply cover the damage with self-levelling sealant, as long as the hole is on a fully horizontal surface. Use only Dicor ® brand self-levelling sealant, as other sealants may not be compatible with the rubber material.

Small tears may be repaired the same way, but in the example used for this article, sealant repair was not possible due to the fact the damage was on the edge of the roof. Self-levelling sealant would not work in this case, as it would run off the edge of the roof. Additionally, while sealant does generally provide a robust repair, using Eternabond® tape offers a much more permanent solution.

The image above shows a moderate roof tear on the edge of the roof. As mentioned, this would not be a suitable location to use sealant, and the area is also fairly large. As shown in the photo, there is also potential for wood damage. Due to this, it was necessary to remove a section of the rubber in order to perform a proper inspection of the wood underlay. Note that in this photo, the transition moulding has been removed to facilitate proper repair. In cases where the damage is close to the edge of the roof or extends past it, the corner moulding must be either removed or pulled back as shown in the photo below.

Using a T-square, lines were drawn on the rubber material to indicate where the rubber will be cut to facilitate the repair.

The rubber was carefully cut all the way to the edge of the rubber and removed.

In this case, no wood damage was found (the hole shown in the photo is one of the screws holding down the roof underlay).

In order to help prevent the loose rubber edges from lifting off the wood, staples were applied around the perimeter of the cut.

Two pieces of Eternabond® were cut to overlay (and overlap) the damaged area.

Arguably, the cut area could have been smaller in this example such that a single piece of 6” Eternabond® could have been used. While Eternabond® is fairly expensive, I highly recommend carrying a roll of it in your RV, as it can be used for many different repairs, most notably roof and sidewall damage. It is completely waterproof and lasts virtually forever if it is properly applied. Proper application includes thoroughly cleaning the surface and firmly applying the Eternabond®.

Once the damaged area (including the newly exposed wood) was thoroughly cleaned using denatured alcohol (or Eternabond® primer), the clear backing plastic was removed from the gray side of the Eternabond ® tape and the tape was applied to the damaged area. When applying Eternabond® after the backing is removed, be sure to place it properly the first time, as the gray putty surface is quite unforgiving.

After the tape is applied, it is extremely important to apply pressure to the entire Eternabond® surface to properly activate the putty against the surface. This is best achieved using a steel roller, but you can also use your hands. Do not rush this step, as it is important the Eternabond® is fully affixed to the surface across its entire area. Do your best to avoid any creases in the tape, but do not lift the tape in an attempt to eliminate creases unless the crease is severe. It is often possible to roll or press out minor creases or bubbles. From the photo, you can see there are no creases, and the imperfections in the Eternabond® are simply where the elevation of the tape changes from the wood to the rubber.

Once the Eternabond® was fully applied, the moulding was replaced. For Eternabond® repairs, the most important thing is to ensure the edges are fully sealed to prevent water entry at any point. If there is any question regarding the possibility of water entry, self-levelling sealant can be applied over the interface between the rubber and the Eternabond®, but again this is only possible on a fully horizontal surface. It is best to secure the Eternabond® to the repaired surface and eliminate any water paths under the tape.

While using Eternabond® to repair roof (or sidewall) damage may not be pretty, it is a highly effective method of repairing and hiding damage. It is also virtually waterproof and largely permanent if time is taken to properly apply it.

Hopefully this article has provided some helpful hints to help you deal with minor damage you may encounter to your RV roof or sidewalls.

Don’t forget to perform annual inspection and maintenance on your RV roof and other sealants to avoid water entry points.

Questions, Comments? Please leave your thoughts below.

Steve Froese
Author: Steve FroeseEmail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Steve Froese is a Licensed Professional Engineer in British Columbia, as well as an Interprovincial Red Seal RV Technician, which is equivalent to a Master Certified RV Technician in the USA. Steve was a personal friend and colleague of the late Gary Bunzer (“the RV Doctor”), and works closely with FMCA as the monthly “Tech Talk” columnist, as well as being a member of the Technical Advisory and Education Committees. Steve and his family are lifelong and avid RVers, mostly in the Pacific Northwest.

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