Having gone through the whole skylight replacement ordeal, and knowing now that the skylight does not leak, primarily due to our careful replacement and our diligent efforts to ensure that the new skylight sits flush (something the factory doesn't bother to do, I might add), I can offer this advice:
1. If your TT is still under warranty take it to a dealer right away. Water damage can add up fast, and wet wood draws in carpenter ants.
2. In the short run, you can do what we did and buy a small dehumidifier and short drain hose, and stick the dehumidifier in the shower stall itself and let it run whenever the TT (or shower) is unoccupied. The dehumidifier will dry the interior space out really well. It will not resolve internal leak damage however. After my own experience, I realize we could have ended up with the same problem you describe, we just got lucky and the water leaked out through the inner garnish and landed on the shower stall floor instead of running down the wall.
3. Also, you can easily remove the inner garnish and figure out if there is wet wood under the skylight. This is crucial. The inner garnish above the shower stall comes out if you remove the 6 phillips head white screws. We could not really see the extent of the cracking and leaking until we removed the garnish, but after that it was obvious there was a problem.
4. After you get the inner plastic garnish removed, if you can look up and see cracking near the exterior-most edge of the skylight, or water damage to the trusses or wood blocking underneath the skylight, then you know you have a skylight or roof leak (or both). Keep in mind, it only takes a tiny crack in the sealant around the skylight, or small crack in the skylight itself, to let water thru in sufficient quantities to do a lot of damage. For example, a crack in the sealant, possibly caused by a non-flush installation of the OEM skylight itself, would allow water to get down and under the butyl rubber of the roof and it could easily run down the inside wall. The good news is that it sounds like you have caught the problem in time, so it's also possible to dry out the original wood, if it is not rotten, with the dehumidifier running round the clock-if you can also find and fix the leak.
Of course, if it's still under warranty, all of this is best done at a reputable dealer's service department. You might have to give up your TT for a day or two- but it's worth it.
Finally, if you have to replace the skylight yourself, you can order the skylight from F.R. with your FR VIN number. Just be sure to buy some DOUBLE-SIDED ETERNABOND tape from ETERNABOND, or one of their reps, or from a local RV dealer. FR does not supply DOUBLE-SIDED Eternabond tape. FR only ships the SINGLE-SIDED Eternabond tape, which they expect you to use on the exterior side of the skylight flange (where you would normally use DICOR sealant. Not practical. Double-sided Eternabond tape will make this replacement/repair a snap.
P.S.: The root cause of OUR problem turned out to be the fact that the factory did not install the skylight flush to the roof. Apparently, they think hard plastic skylights can bend to fit a curved roof surface. Being an engineer, I can assure you this is a recipe for leaks and warranty problems, especially if the skylight is exposed to temperature changes, so I recommend using some kind of rubber or plastic as a shimming material if this proves to be the case. The skylight should sit as flush as possible.
Also, we used those rust-proof specialty self tapping screws used for attaching metal roofing - the kind with the EDPM washers on them - to secure our new skylight to the roof. Our theory is that the EDPM washers will prevent leaking and cracking around the screwholes of the skylight, and allow some flexing of the skylight during temperature changes without it cracking. So far, so good.
Good luck. Post back what you find out with your leak.
Originally Posted by Kstalvey
I have an '07 Flagstaff 831BHSS. I have slight water damage in the bathroom above the shower where the wall meets the ceiling. It is close to the rear corner of the TT. I have checked the roof, skylight, and corner and found nothing visibly wrong with the sealant. However, I have noticed a lot of condensation on the inside of the outer skylight. Could the minor damage be coming from the condensation? Is the condensation coming from a damaged skylight? Help me please!