Tried covers without success. They do more damage than they help I found and they are expensive and cannot take wind. I have a barn now and keep it in there. Anything you can do to keep the sun off of it is a help, (rv storage building, awning over the top, etc. Sun ultimately rots anything plastic and over time degrades your EPDM roof. It also fades your caps and ages the trailer faster than keeping it covered. Snow load is also a consideration depending on where you live so be aware of how much snow the trailer will hold on the roof.
2017 Crusader 315
2016 Boston Whaler Montauk 150
Former Montana owner
Colorado Cruiser, Over the Pass and Down the Hill