Dave H M wrote:
What is wrong with just leaving the roof alone.
EPDM naturally chalks and when it does it carries dirt off the roof which appear as black streaks on the side of the trailer, the longer those streaks remain the more they become embedded in the side wall material and the tougher it is to get rid of them. Using spout extensions helps, cleaning the roof a couple times each season also helps, as does sealing the EPDM surface with a conditioner. It's your trailer you can do what you want with it but many of us prefer to wash the roof occasionally to help minimize this streaking.