I clean our once maybe twice a year.
I clean it when I'm dewinterizing it and then maybe once during the season or when I'm winterizing it.
When I clean it I also check all the seals on sides and around vents, etc. to make sure they're ok.
I use either a roof cleaner or mild water-soap mixture. I also use a bleach-water mixture sometimes to try to clean the spots.
I’m sure you’re going to get a lot of variations on how and the number of times people clean their roofs.
A lot depends on your geographical location, where you camp, where the trailer is stored, etc. with how dirty your roof gets and the amount of times you should clean it.
Mary & Tom (aka Hutch)
2015 Jayco Eagle Premier 361REQS
2014 GMC Sierra 3500HD 4x4 CC D/A
Sunlines: 2005 Solaris T-280SR; 1999 Solaris T-2670; 1998 Saturn T-24A