Exactly... glad you guys knew what I was talking about. Figured it shouldn't be an issue since we plan to have a cover for it for while it is not in use, so the windows would only be exposed when we camp & we rarely encounter rain.
I believe we are getting a great deal on it ($9000 for a 1998 Residency with just under 29k miles). Only issues are the windows, back up camera doesn't work, fuel gauge not working, ice maker not working and the awning over the slide out needs to be replaced. All tires are 3 years old & have been covered by wood when parked.
Just want to find out how much it will be to repair or replace the windows, should they become an issue.
Thank you for the advice & thank you for the link Jim.