Winnebago Class A Roof Construction

[BKing49]

Does anyone know how the roof/ceiling of a Winnebago Brave (older - '95) is constructed? I believe that the actual roof is a sandwiched laun/Styrofoam/laun assembly, but not sure. I think that because when I drilled a hole in it for a screw, the drill popped through after only about an eight of an inch. Meaning the screw is into the Styrofoam.

I need to run a cable above the ceiling and below the roof and want to make sure there is a "void" in which the cable can be ran.

Since the roof will hold my full weight with little sign of deflection, there must be some kind of truss arrangement supporting the roof panel allowing for a ceiling panel to be attached to the bottom of the truss.

Is this correct?

Bruce

[Clay_L]

My 96 Warrior had an aluminum roof and they use fiberglass now but I think the process is the same.
There are no voids as such.
The roof is laminated in one piece. The thin fiberglass sheet (1/16 inch or so) is bought already laminated to 1/8 inch thick luan. That is layered with Styrofoam 4x8 sheets, then the inside wall covering pre-laminated with luan. They use huge numerical controlled routers to cut paths for wiring and aluminum roof trusses and structure before lamination. A water based contact cement is used as the bonding agent. The whole roof goes through huge rollers to press it all together. Here is a cross section picture of the roof edge,

[the_bear_II]

Winnebago was known for using the sandwich technique so there won't be a void. Plus they ran stringers across every so often kind of like rafters.
The technique made for a very strong roof, I can remember a commercial with a bunch of people standing on top of one of their MHs.

All of the wiring was pre run before the sandwich process. You may have to run through cabinets or use Latch Duct across the ceiling http://www.cablemanagementsupply.com/raceways/latching-duct.html