Any problems with foil-backed foam being too thick?

[cracker39]

I am glad I only bought 2 sheets of R-Matt Plus 3 foil backed foam to do my floor. When I put some in a space in my side wall, it was actually thicker than the framing. I'm afraid that I'll have problems getting my paneling to stick to the wood. Has anyone had any problems with this type of insulation and attaching their paneling? I had planned to use only adhesive on the framing pieces and use my brad nailer on the edges and jointss and cover both with molding.

Now, I am considering looking for 3/4" foam that is only 3/4" even it it is the cheaper foam. I can always stick aluminum foil in with spray adhesive for heat reflection.

[asianflava]

One problem I had, was the framing being too thin. I found out that furring strips are thinner than 1X2's.

[cracker39]

I ripped all of my framing from 1x8s. They are usually right on 3/4" thick. The foam sheets don't seem to be uniform in thicknbess. I think that's the problem. But, when paneling adhesive is applied to the framing, it will flatten out to whatever the thickness of the gap is, and it won't be more than 1/16 of an inch anyway. So, maybe it won't be a problem.

[Mitheral]

I can always stick aluminium foil in with spray adhesive for heat reflection.

Unless you've got an air space next to the foil don't bother as the aluminium isn't going to do much.

[Finntec]

I used poplar 1x3s and used 3/4" alum foam. I had to cut Vs out of the underside of the foam to make the curves right. The first time I tried to use staples and caulking. The caulk dried too fast in the heat of the day, and the staples pulled out. After cleaning(Foam), sanding & sealing the wood, I used Gorilla glue on everything. It worked much better. I wished I had insulated the side now.

[Gage]

I used 1"x2"'s for my framing so 3/4" foam (alum backed) worked just fine. I didn't use any glue, just sandwiched it in. Worked great for me. Oh, and I didn't have to cut any groves in it to match the curve of the roof and front.


Have a good day.

[asianflava]

That's the same foam I used for my floor and walls, 3/4" R-tech EPS foam. I didn't think it would bend very well so I used the white styrofoam on the roof.

[Arne]

I discovered the same problem with furring strips, not quite 3/4" thick. Since I had mixed and matched them with true 3/4" (1 bys), where I had a problem, I held a serrated bread knife flat on the furring strips and shaved and tapered the foam back about 6 inches and made it work... but will not make the same mistake again.

[cracker39]

Gage, the R-Matte foil backed foam that I have is pretty stiff and resists bending. Did you have to force yours to bend before putting it in the curved areas? Or, is the R-Tech more bendable. Does is have a skin on both sides like mine does? Did the R-Tech come from Lowes?

I haven't skinned my top yet, so I haven't tried to get the R-Matte backed foam to bend the front curve. Actually, it won't have to make the entire curve, as the roof spars are 1 1/1" thick and the foam is 3/4" thick. That allows for some straigntening of the foam in the curve. For the straighter top areas, I think I'll also put in a layer of 1/2" regular cheap foam for 1 1/4" insulation.

For running wire grooves in the foam, I took the "handles" off of a 2" binder clip and reshaped one into a cutting tip for my soldering gun. The metal is just a skosh smaller diameter than the tips that came with the gun, but will tighten in the tip holders. Depending on the angle that I hold it, it will cut up to the width of the flat nomex 12GA 2+1. It also burns through the vinly/paper layer on top. I made a groove in a test piece that held the 12 ga snug and flush with the surface so nothing was needed to keep it in place.

[Gage]

Dale, the R-Matte that I have is foil backed and has a film type skin on the other side and yes I got it at Lowe's. I cut it a little larger than the hole it was going to fill and pressed it in place. It's a little stiff but held form. I think 3/4" is about as thick as you would want to try. I also didn't use any adhesive.



Hope that help'd. Have a good day.

[cracker39]

I bought 4 more sheets of the R-Matte today. One sheet is definitely thicker than the others. I'll use that one in my roof where I have 1 1/2" of space. I finished putting the foam in the spaces in my walls except for one spot on each side where framing may be added. I'll just leave that bare for now. I didn't use any adhesive either.If I cut one too loose, I just cut a sliver to stuff in the edge to make it secure.

That's a tedious job when you have more than 20 individual spaces in each wall like I do, and many with angles. I found the best tool to cut it is one of those slender utility knives that has the break off blades. I let out an inch to trace the cut along a metal yard stick, then push out another inch of blade and use it to slice. I can slice off an eighth of an inch of foam with it without it crumbling. That is, the high density foam like R-Matte. BTW, I got mine at HD. It's a dollar cheaper per sheet than at Lowes.

[asianflava]

I preferred the cordless circular saw, even though it made a mess. The edges were nice and clean as well as square. I tried a couple different blades but they (or I) couldn't get the cut even. What I mean is, I used many cuts that got progressively deeper. When it was done the edge had a layered look to it.

Foam is probably the only thing I can cut with that useless saw.

[glassice]

One way to do hard foam in a curved that makes it supper strong is cut 1" strips lay in then install inner skin and very carefully shoot 2 part foam bonds to inside skin .outside make like 1 piece with foam be careful that it dose not Puff the skins .If you try just with 2 part foam it cost to much

[Geron]

Dale, the R-Matte that I have is foil backed and has a film type skin on the other side and yes I got it at Lowe's. I cut it a little larger than the hole it was going to fill and pressed it in place. It's a little stiff but held form. I think 3/4" is about as thick as you would want to try. I also didn't use any adhesive.



Hope that help'd. Have a good day.

If my brain is working right from the photos I gather that you skinned the outside first then pressed the insulation in from the inside. Once in place the inside curve held the foam in place -- it couldn't pop out. Is that how you did it???

g

[Classic Finn]

Hi there..

You speak of Foil Back Foam.... What Is the purpose for its use? Is that for the prevention of condensation or?


Curious as usual

Classic Finn