[Wisconsin Retiree]

I liked this guy's answer from years ago:

Posted By: jwmII on 10/15/09 05:21pm

Your tires worst enemy is moisture coming out of whatever the rv is parked on. This contributes to the dry rot that everyone attributes to the sun. Don't get me wrong as the sun is a contributor but not nearly as harsh as moisture. You can park on gravel,dirt,concrete, wood, asphalt, and anything else that is porous and retains moisture and dry rot will attack your tires.
Some who have poured concrete slabs to park on have laid down plastic and poured over that but that still does not stop moisture from coming up out of the concrete.

You need a barrier to park each tire on that moisture cannot permeate.Only then can you help stop the dry rot attack. That can be metal like sheet metal flashing used by roofers either aluminum or steel. It can be plastic, like plastic cutting boards and there are even some high dollar plastic shields sold expressly for parking on. Be sure as well that water cannot puddle around your tires where ever you park and store the rv.