How often do you clean or treat you roof.

Twice a year, wash with RV rubber roof cleaner and RV rubber roof treatment. In the Spring (usually, late April if weather warms up good), and usually October. If black streaking starts on the side between April and October, I'll wash it down with just a long handled brush and water. No soap. This usually takes care of it. I do not get on the roof washing it. I do get on the roof to treat it, since I apply with a sponge and then use a squeegie to spread it around. And on an arched roof, that's a real trick!

Maybe I'm a bit anal here, but I think taking care of the roof properly is THE most important thing to do to a camper! Absolutely the most.