TROUBLE with Filon roof

[ranger378]

My 2000 Safari Class C (made by Harney) has a textured fiberglass (filon) roof. I originally thought it was a membrane but after further investigation it is defiantly filon. The problem is it is lifting in some areas. If I press on it it will actually move up and down in some spots. It seems the adhesive is no longer bonding to the roof. The roof itself feels solid when I walk on it and I see no indication of leaking. Is there something I can do to fix this? Will the entire roof need to be replaced? Has anyone ever had this issue with an older filon roof? It's especially bad in one area.
I have no experience with filon at all. I owned one RV and that was 25 years ago. That one had an EPDM roof which I replaced bu I think filon is a whole different beast. Would this be the sae as a fiberglass sidewall delaminating?
I really don't know how to proceed. Any help is appreciated. THANKS!

[Gjac]

I would rebond the roof back to the substructure. There are a number of good adhesives to use but in the case of what you are describing I would use something with a high viscosity like a polyurethane adhesive so it flows into the disbonded area.If you already have epoxy resin I would use that thinned with a solvent like acetone. If not the polyurethane will be cheaper. I would drill a .250 to .375 hole through the skin then inject the adhesive using a hypodermic needle and a piece of plastic tubing. If you drill the hole in the middle of the disbonded area you can see and feel the structure underneath to insure it is still good as you believed. After you inject the adhesive roll from the hole to the edges of the disbonded area to ensure adhesive get to all the area that was disbonded. After curing just seat the hole with caulk or if you use epoxy just use it for a seal. This would be similar to a sidewall delamination repair. If the disbonded areas are in the middle of your roof and not around any cutouts in the roof as I think your are describing in your op it is probably not due to water intrusion but rather to the adhesive failing.

[charlessfolly]

Winnebago motor homes had a problem with their fiberglass roofs -1999/2000.Problem with roof material peeling back while driving down road and tearing off.Something to do with leading edge not overlapped by trim edge enough...I think.
Check older rv.net forums.about 2006 maybe?