I appreciate all of the responses. I recently spent close to $1000.00 having my roof recaulked as a result of sitting in the storage lot baking in the oven of So. Cal. I really wasn't looking for the merits of covering or not covering. What I was looking for is: Does anyone out there know of a manufacture that makes "Tyvek" roof cover for a 37ft. Class A. If someone doesn't want to cover their RV when it sits outside, then that is certainly up to them. Believe me I have been RV ing for over 35 years and seen my share of roof damage from the California Sun. I am disabled to the extent that a full cover is not practical for me to deal with. I was thinking just a roof cover would be something that I and another person could handle.