what Tony said. Mine was a water issue. I bought it messed up as a project. The skylight had been damaged and never covered along with some other leaky spots. The people I bought it from put a new roof on and then lost his job so I continued the fun.
most damage too the floor is a water leak someplace.
1996 Damon DayBreak 2500 454 P37 Chassis
NRA Benefactor, NRA & OSBI Certified firearms instructor, Retired Electrical Engineering Tech