I'm actually knee deep in a roof rebuild. I too bought a leaker and the more I uncovered the more I found. I finally broke down and just started tearing off everything. Currently my Salem 295BHSS is down to the rotted trusses but amazingly the walls seem to be in fine shape (with the exception of the front wall which I will also rebuild). I'm trying to figure out the best material to use for new trusses this week so i can attack the project next weekend again. Option #1 is to buy/build exact replacement trusses which look to be 1x1.5inch laminated bow rafters. I may cut the old rafters out and leave the wiring in place or have to reroute it through the new rafters. Option #2 is to build some other type of rafter, maybe cut down 2x6's. Regardless of which I choose, I will end up with a more sturdy roof when finished. In my opinion the factory trusses are marginal for strength at best. As for roof sheeting I'm thinking of 1/4" marine rated plywood laid perpendicular to the trailer, glued and screwed. Then another 1/4" layer glued and screwed to it, laid inline with trailer. Encapsulated insulation underneath then comes the options for the inner ceiling. Option #1 is go back with the white luan similar to factory. Option #2 I'm considering is a suspended ceiling mounted directly to furring strips perpendicular to trailer. I need to physically look at those materials and do some measuring but I'm thinking I can get away with losing only 1 to 1.5" of height in the trailer. This wouldn't be a problem as I'm the tallest in my family at 5'6". The advantage of the suspended ceiling is I can anchor my wiring underneath the new trusses without unhooking anything as the furring strips would give me clearance. Also, I will always have access to the underside of roof for inspection and could even remove a panel or to during the winter to keep away condensation on underside of roof. I need to be sure I have enough clearance for the inner flange on slide out before I go and lower the ceiling though.
One thing is for sure - after ripping the old stuff out I've learned a lot about rv roofs. Even when you think it's good it still may be molding. What looked like a sagging ceiling panel when I purchased turned out to be completely rotten rafters. Once the new rubber roof is installed I will be the guy that religiously maintains it. In one way I wish I just bought something ready to go, but I'd be willing to bet that many if not most rv's bought used have some degree of water damage. It's just a matter of time before it gets bad enough to see the effects. And by then it's too late to correct the problem, only replacement will fix it. I started a thread on rv.net and have some pictures posted there. Any advice on rafters/roof/ceiling are welcome.
RV.Net Open Roads Forum: New to TT, boy did I get in deep