I cover mine in winter, that's half the year in Minnesota, they work great but I ran into trouble with the rain spouts ( gutters ) tearing holes in it. I wrap the spouts with bubble wrap and a rubber band and that worked till a big wind knocked a. Couple off and know I have tears, the covers are several hundred $ for a 31 ft fifth wheel camper. So I'll patch it up and re enforce the weak spots.
Jack & Kim Blaydes
2011 Rockwood 8285WS (The Mobile Cabin)
2004 F350 SuperCab 6.0TD DRW (Mr. Duals)
and Sissy (The Siberian)