smlranger wrote:
I'm not a great fan of using pressure washers on the motorhome, especially the roof.
The coach we just got also had some sort of sticky little round deposits on the fiberglass roof. I could not really scrub them off. So, I had one of those metal floor scrapers on a long handle (like you would use to scrape chewing gum off a floor). I used Turtle Wax Zip Wash. I wet the roof, used the scraper to loosen the deposits, then scrubbed the area with a long handled stiff brush. It cleaned up really well.
I use 303 Protectant on the roof after washing it.
Wouldn't use a pressure washer but used a metal scraper? I think I'm just the opposite. I use the pressure washer on my fiberglass roof at least once a year but I don't think I'd be up there with a metal scraper on the fiberglass. The thing you need to be careful about with the pressure washer is hitting sealant and the various plastic parts up there. But mine has not damaged the fiberglass at all that I can tell.