harold1946 wrote:
If the roofing material is EPDM its normal for the top layer to sluff off over the years, with the resulting black spots appearing. They do not compromise the roof but eventually looks pretty bad. The only fix is to recoat with a product like Dicor rubber roof coating to restore the finish.
This natural "SLUFFING" of the top coating is why I feel you shouldn't touch your roof regardless of what even the manufacturer might say in the RV world. By even lightly scrubbing the roof you are only promoting the "SLUFFING" and lessening the life of the roof. This only promotes premature aging and cracking and loss of the top UV white layer of the EDPM material. The only reason to wash it is to help prevent black streaks and if you do what I did for around a one time cost of $150 you can eliminate 99.9% of the black streaks ...
Black Streak and Stain Relief. a HUGE side benefit of this system is it virtually eliminates leaks from the sides like windows, etc. since it eliminates any runoff down the sides of the trailer. This benefit alone is worth the $$$.
Larry