How to clean mold / mildew from rubber lap sealant


Junior Member
Hi guys,
I have an ongoing problem with mold growing in and on the white lap sealant that Itasca used on the roof of our class C RV around vents and such. The roof itself cleans up just fine. It's almost like a thin fiberglass roof (06 Navion). I have gotten so desperate that I have even tried diluted bleach directly on the sealant and a small toothbrush. On any other surface, bleach kills mold quickly but this sealant acts as if the mold is inside of it. Any ideas short of tearing up all of my sealant and replacing it? Everything else on the rig looks great except for the dang sealant.


Senior Member
Hi Blan and welcome to the RVUSA Forum. If the mold is on the roof, and no one can see it, and there aren't any other problems, such as leaks, I would just let it be. If the mold is on the sealant around things poking out thru the sides of the rig, then you could pull off the old sealant and re-caulk. Or not. I'm not real big on appearance issues as long as everything works.