If it is algae, it means your roof is in damp conditions, is it parked beneath a tree? I'm not sure which is the best way to clean it off, but if you look under "Cleaner" in this forum section last post at
13 Nov 2005 05:06 PM
you will see advice given about removal. To stop it comming back remove either the light or the water allowing it to grow.
YES ITS ALGAE. VAN AT A FARM WHERE I STORE IT .BEEN KEEPING IT THERE FOR A YEAR.VAN BEEN OUT 10 TIMES THIS SEASON AND NEVER HAD THIS PROBLEM NO TREES VAN IN OPEN.
Plenty of food for algae to feed on around a farm, and it does not take long to grow once established. Is the van in a sheltered position? Without moisture, algae should not be a problem. Once you clean it off, give it a good coat of wax (easier said than done I know) to help the water drain.
Darren, a strong mix of Fenwicks Caravan Cleaner (double the normal) will shift the algae with the help of a soft bristled, long handled car washing brush, and a step ladder.
thanks for all your help. will try your ideas.did see that rain was sitting on roof because i do store level .think i need to clean and go off-level thanks again.....