The rear wall is built differently than the side walls and the slide walls. The rear wall is constructed much like a "stick/brick" wall with hand laid fiberglass insulation between a sheet of 1/8" luan on the inside and a free hanging sheet of 1/8" FILON on the outside. The side walls are constructed of 2" aluminum (in almost all Keystone RV's) studding, welded into a complete wall panel, with 1/8" luan on the inside, foam insulation between all of the aluminum struts and 1/8" FILON on the outside. Many (not all) also have a layer of 1/8" luan on the outside of the styrofoam, under the FILON. On some of the luxury models, there are two sheets of luan, laid so the seams overlap and don't match. This is to prevent the "wavering" that can be seen on the "standard build and premium build" models.
Once the assembly is ready to "bond", a thin film of spray adhesive is applied to the Styrofoam on both sides and also to the luan (if it is used on the outside) and the entire assembly is "pressed together with heavy rollers, sealed in a vacuum "bag" to pull the components together and left to dry.
Once dry, the layers are, for the most part, a single unit and can't be separated. At this point, windows, doors and hatches are cut/routed in the appropriate places and the wall is installed on the chassis and braced in place until all the walls and roof rafters are installed. At that point, it becomes, essentially a "rigid box".
If you go to the Laredo webpage and download the current brochure,
http://www.keystonerv.com/request-a-...s?brand=Laredo there is a diagram of how the trailer is constructed. It shows the aluminum, Styrofoam, luan inner and outer panels and the filon. As I said, the rear wall and the slide out walls are not constructed the same way.
Linear Mode
