Adhesive for insulation foam board
I am redoing a couple sections of the roof on my Fifth wheel. I removed the membrane of the whole roof. Then I removed the 1/4"plywood and the 2.5" insulation foam from the sections I am replacing,...
Forum Discussion
The sections I am working on, are flat. No rounded/curved areas. The reason for the repair is that water had slowly, over time, leaked under the roof membrane at the end of the roof at front and rear, without me being aware of it.
The water got trapped and soaked part of the plywood under the membrane. I am replacing the whole affected section, rather than just the damage area.
The plan, for the front section, is to use a 4x8 1.5” foamboard, with cutouts for the air ducts and speakers, etc.., and then glue an uncut 4x8 1” foamboard on top of it, and then glue the 4x8 ¼” plywood on top of that. Same with the 2x8 section in the rear.
The edges of the 4x8 plywood will extend over on top of the aluminum frames, the foam boards will actually be cut to fit between the frames, and the plywood overlapping, and glued & screwed to the frames.
I can glue the two foamboards and the top plywood together offsite, clamping them together, as has been suggested, and then install the sandwiched section gluing it to the ceiling panel, using compression support from below the ceiling. As I mentioned earlier, the top overlapping plywood will be attached to the top of the aluminum frames. The bottom, ceiling panel, is sandwiched between 2 aluminum frames, I think, so difficult to replace properly.
I will still consider using a 2.5” foam board, but I do like the idea and want to experiment with the 1” + 1.5” option.
For foamboard, the local Home Depot has Owens pink Foamular NGX 150 XPS and R-tech EPS white panels. The R-tech white styrofoam is the same type as what Forest River used on this trailer. Seems to be rather soft, compared to Owens rigid foam.
I will experiment with samplings of both types of foams, with the different types of adhesives that have been suggested here, but I doubt I will use the R-tech panels. The Owens pink panels seem to be way more rigid than the original white soft styrofoam used in this trailer.
This cross-section profile is not correct proportion and scale, just an illustration of how I am thinking of building the roof.
Edit: Forgot to mention that the styrofoam also been damaged by ants getting in there. It also difficult to separate the plywood without damaging the styrofoam, so that's why I am also replacing the styrofoam insulation.
The water got trapped and soaked part of the plywood under the membrane. I am replacing the whole affected section, rather than just the damage area.
The plan, for the front section, is to use a 4x8 1.5” foamboard, with cutouts for the air ducts and speakers, etc.., and then glue an uncut 4x8 1” foamboard on top of it, and then glue the 4x8 ¼” plywood on top of that. Same with the 2x8 section in the rear.
The edges of the 4x8 plywood will extend over on top of the aluminum frames, the foam boards will actually be cut to fit between the frames, and the plywood overlapping, and glued & screwed to the frames.
I can glue the two foamboards and the top plywood together offsite, clamping them together, as has been suggested, and then install the sandwiched section gluing it to the ceiling panel, using compression support from below the ceiling. As I mentioned earlier, the top overlapping plywood will be attached to the top of the aluminum frames. The bottom, ceiling panel, is sandwiched between 2 aluminum frames, I think, so difficult to replace properly.
I will still consider using a 2.5” foam board, but I do like the idea and want to experiment with the 1” + 1.5” option.
For foamboard, the local Home Depot has Owens pink Foamular NGX 150 XPS and R-tech EPS white panels. The R-tech white styrofoam is the same type as what Forest River used on this trailer. Seems to be rather soft, compared to Owens rigid foam.
I will experiment with samplings of both types of foams, with the different types of adhesives that have been suggested here, but I doubt I will use the R-tech panels. The Owens pink panels seem to be way more rigid than the original white soft styrofoam used in this trailer.
This cross-section profile is not correct proportion and scale, just an illustration of how I am thinking of building the roof.
Edit: Forgot to mention that the styrofoam also been damaged by ants getting in there. It also difficult to separate the plywood without damaging the styrofoam, so that's why I am also replacing the styrofoam insulation.
