The most common cause of the delamination you are experiencing on your 5th wheel trailer is moisture getting into the layers of materials and causing the glue to fail and the layers to separate. I am not sure why you think that the moisture was a temporary problem, in most cases the delamination process will continue until the leak in the RV is repaired.
Putting a new front cap over the damaged front cap of your trailer is not a viable method of repairing the problem you are having.
It sounds like you have already found someone to do the repairs for you and hopefully they will be able to determine where the moisture is coming from and repair that along with the delamination. Because if they don't find the source of the moisture the problem you are having now is going to repeat itself.
Just a note here; the most common place for leaks to occur on these 5th wheel trailers is the seam where the front cap joins the roof of the RV. Even after the repairs you will need to inspect this seam at least twice a year to make sure that it stays in good shape and does not start leaking again.
There is a product you can use to prevent this seam from ever leaking again called EternaBond Roof Tape. EternaBond is specifically designed for the RVer. It utilizes Eternabond's advanced MicroSealant Technology with built-in primers and a specialized white UV stable backing. Perfect for all RV roof repairs and maintenance. Truly a one step process. Very little pre-cleaning necessary.
Use EternaBond Roof Tape over roof seams one time and never do roof seam maintenance again! It has a 25 year warranty! More than 25 high-end RV manufacturers now use EternaBond products in the manufacturing of their RVs to ensure their customers will truly have a weather tight, leak-proof RV. By the way the only tools you need to use EternaBond is a pair of scissors.
You should use this around all of your trailer's vents and any accessories that are attached to the roof. You should use it even if the caulking, sealant looks good as it will prevent any future leaks from occurring. It can also be used to patch any holes or cracks you may have in your roof.
To see how easy it is to use EternaBond take a look at the video below.
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