Gelcoat blistering is a common problem with watercraft, fresh and salt water both. When it involves a non submerged structure, its causes are usually indicative of a poor construction or inferior fiberglass layup materials.

For those of you that have fiberglass roofs with structural issues, and whose trailers are no longer covered by a warranty, I would recommend you visit a boat yard instead of a RV dealership. Most fiberglass structures can be rebuilt and strengthened in place, without having to replace the entire laminate. The material and labour costs for the repairs will be much lower than a total metal replacement. Boat yards that typically effect fiberglass repairs are versed in this type of reconstruction.

The problem with any fiberglass construction is the harm done by UV rays, which damages the outer most layers of a fiberglass lamination. An inferior layup's surface can only include the laminating resin, whilst a better lay up will have an additional gel coating protection layer. The type of resins that were used in the FRP lay up, in addition to the numerous fiberglass and core materials that are available, can result in very different qualities of finished products. Just as with any construction, there are many ways to build a fiberglass layup. Not all are equal, and one type can't be directly compared to another.

The repairs would include sanding the damaged areas, removing any delaminations, adding new materials, and finishing with a new gel coating or final paint product. Usually the interior would not have to be addressed as the repairs would be limited to the top of the present roof. Replacing an entire roof, especially with a different material, particularly if it involves a finished LQ, is very labour intensive. Fiberglass repairs, when compared to sheet metal, are much easier and less expensive to effect.

For what it is worth, we have installed a full aluminum roof overlay on several Cimarrons with the delamination issue. Basically we leave the original roof intact, and add a full .040 coil skin that is sealed at the edge and around vents like every other traditional roof (same material we use when we have to replace a traditional roof). It seems to have worked very well, it is not cheap, but a reasonable alternative to replacement with what should be a permenant solution. Did our first one back in '05 or so, and several since. As was pointed out with an LQ- this lets all of that not be disturbed.

Also for what it is worth, the last one we did had the factory authorized "fix" applied several years ago. Roof still came apart. It wasn't leaking, but it had severe delamination. So no matter what, keep a close eye on those units before any damage occurs.

We had a roof issue with our 2008 Cimmeron. I could see that the fiberglass was delaming in two small spots.  I contacted my dealer at Transwest in Kansas City and she hooked me up with Cimmeron.  They had a person from Ohio come to Iowa and repair my roof. He repaired it like a body shop would repair fiberglass on a car.  I learned alot about fiberglass and upkeep that day.  He told me to keep my roof waxed with a good paste car wax once a year. I did that immediatly after he left and every year after that. I did not have any more issues with the roof.  I have traded that trailer, and purchased another Cimmeron, and I wax the roof with a paste wax, and I also wash the roof everytime I wash the trailer, no signs of any delaming.  Love the Cimmeron trailers.  Call Trisha at Transwest in Kansas City.  They are a Cimmeron dealer, and she may be able to point you in the direction you need to go. Good Luck!