Originally Posted by Tom Trostel
My Compact Jr and Bigfoot
both have plywood floors covered with vinyl inside and painted only underneath. Both still have the original plywood and are solid. One is 42 years old and the other is 35 years old. Most floors fail due to water leaks
17 is different from Tom's. My floor is plywood but the bottom is fiberglass. I never knew the first Bigfoots did not have fiberglass underneath. As Tom said, water leaks
from above are usually the culprit.
There are some threads on the forum that indicate some manufacturers sometimes, but not always, used OSB or something other than plywood and a trailer with OSB would be a concern. A floor replacement would be a major project.