I recently purchased a 1999 Citation truck camper which has a small soft spot in the roof. I used rope to outline the area that has been affected by water. Within this area, there are two very soft spots, each about 6"x6".
I probably could have just resealed the roof and let it be (as several local shops recommended), but I wanted a more solid fix ... so I took off the gutter and part of the front molding, and pulled back the EPDM from the offending corner of the roof.
As you can see from the above photo, the fiberglass has started to delaminate. Fortunately, it's not too bad ... the luan is still solid, and the delamination only goes down about 1.5 inches. It doesn't look like the water got any further than that.
Starting to pull out the bad wood:
Cleaned up a bit more:
At this point, I've removed all of the wood that didn't have any structure left in it. I think I'm going to cut out some more of the water-affected framing, and then treat what's left with some sort of an epoxy. Then I'll splice in some new cross member pieces. I picked up a Kreg pocket hole jig and some clear vertical grain doug fir (overkill) 2x2's at Lowes today. We'll see how that goes ... I'm used to framing with 2x4's!
Stay tunes for updates!