Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 06, 2025 ...

1986 Grand Villa Roof Construction

July 02, 2025, 08:27:46 am

In the process of installing new ACs, I removed the large storage box from the roof. In doing so I pulled up a small square of fiberglass from the old caulk under one corner of the box. I noticed a little water damage in the wood below the fiberglsss. The wood was damp and soft. I am considering cutting back the fiberglass till I get to good wood, replace the damaged wood then fiberglass over. The question I have is, how thick is the plywood that is under the fiberglass? Is it just thin plywood sitting on the frame going crossways, then thin fiberglass over it?

The other question I was wondering, if I would just seal it up, would the damp, soft wood inside eventually dry? Or does this need to be addressed immediately? The inside ceiling is showing no signs of damage.  I put a temporary fiberglass patch over the hole as it is raining daily her in Louisiana, but trying to figure out what is the best plan of action.

Any opinions or thoughts are appreciated.


Mike T

Quote Selected

Re: 1986 Grand Villa Roof Construction

Reply #1 – July 02, 2025, 10:28:29 am

It's about a 1/4 inch thick

Quote Selected

Re: 1986 Grand Villa Roof Construction

Reply #2 – July 02, 2025, 05:13:17 pm

 If you have the AC units off. You will find that they have sunk the roof  and that area is now low and will always leak .  The best fix is too build a slight mound down the center of the roof , so that water runs off and not pools.    Fiberglass  some foam panels into the roof, and add  some good paint to seal the fiberglass.  I would then cover it all with some good real rubber goo.    The old roof may be delaminated in spots and theres a lot of places to leak .  Both caps, windows, Skylight,  etc.     

 I have removed both roof airs and now have a single minisplit mounted in the RF fender well. The roof is covered in solar panels.  It will be a constant hobby to get rid of the leaks.  My next move will be to remove the front end panels and add rubber coating to the roof  on that end.   

Quote Selected

Re: 1986 Grand Villa Roof Construction

Reply #3 – July 02, 2025, 09:39:11 pm

I replaced a approx. 4'x4' section on my roof after a refrigerator fire burned through the roof above the refrigerator. It was patched immediately after the fire so I had no water intrusion issues, just a big hole in the roof.
I cut the hole even on all the edges, replaced the foam board insulation, replaced the plywood with pressure treated 1/4"( could be 3/8, can't remember) plywood, and topped it all with a piece of FRP from the "home store" and used 5200 adhesive to join the fiberglass and plywood together. I then fiberglassed all the edges and finished by applying gel coat to the entire section. Its not a thing of beauty but it solved the problem. All this is covered with solar panels now.
I have a soft spot around my bathroom sky light now and will address this problem the same way.

Quote Selected