The rubber roof on our RV has hundreds of little tiny holes in it. They are through the thin white stuff and show black at the bottom of the hole. We have already gotten the roof very clean. Do we need to seal these? We bought this RV used and I am afraid we got taken.
Lila, (Longview, WA)
Lila, I wouldn’t get too concerned just yet. It’s doubtful those black spots are actually holes in the EPDM rubber material. The rubber roofing membrane consists of a couple plies or layers. I believe you may be seeing the bottom ply and not all the way through the membrane. Older rubber roofs had a definitive black layer on the bottom and it’s usually the thickest layer. The fact that the uppermost layer is showing signs of weathering and oxidation is normal. Normal oxidation is a condition due to the disintegration of surface binders and elastomers, usually by normal weathering. The result is that surface chalking actually removes a portion of the white rubber. This is a normal occurrence and you should not be concerned about the direct effect on the rubber itself. However, if the degree of the wear is severe enough, more drastic measures may need to be taken. For instance, it may be time for a new membrane (most membranes will last 10 – 12 years). Or perhaps a coating of a liquid EPDM material called Liquid Roof, produced by Pro Guard Coatings (www.proguardcoatings.com) can be applied. A lot depends on how old the roof is and to what degree the oxidation has occurred. I would suggest a visit to an established RV service center for a detailed inspection and analysis. Search around for a qualified shop. RV collision repair shops are usually a good bet…or shops that regularly re-roof RVs. It does take a certain expertise. I would try the Liquid Roof product if at all possible, before resorting to a brand new membrane. It’s quite easy to apply.