foam in roof?

[Based]

people have told me I should put spray foam (great stuff) in the holes in the outer skin of my roof so it basically attaches the outer skin of the roof to the inner skin, strengthening it. Should I do this or is there something better? Doesn't foam attract moisture and could cause rust?

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[Jeffdachef 5,000+ posts]

well there is no water unless you have a hole on your roof. However i find great stuff really really weak. It flexes and gets crushed easily. Really want to hear what stronger alternative there is to this also.

 

[Based]

well there is no water unless you have a hole on your roof. However i find great stuff really really weak. It flexes and gets crushed easily. Really want to hear what stronger alternative there is to this also.

People also say to use polyfill... which is just fluffy cotton stuff.... doesn't make sense to me.

 

[Jeffdachef 5,000+ posts]

People also say to use polyfill... which is just fluffy cotton stuff.... doesn't make sense to me.

Yeah for bracing, thats just plain stupid. I think the answer still lies in expanding foam but we need a higher density foam then what great stuff can offer. There's a bunch of industrial strength ones out there but i'm not sure which one's good.

2 part expanding foam http://www.uscomposites.com/foam.html not sure how you would install it though.

also, to alleviate all of your water concerns, these are closed cell foams, it does not absorb or retain water.

people also use liquid nails or PL premium, long cure time but they say its better strength then expanding foam.

 

[Based]

Hmm.... I wanna do some of my roof with damp pro tomorrow just because I don't wanna have to do it all at once when my second pack comes in.. Should I just spray all up in my roof with Great Stuff or should I just leave it?

 

[Popwarhomie 5,000+ posts]

What setup are you running. That would help.

If nothing crazy I wouldn't waste my time.

 

[Based]

What setup are you running. That would help.
If nothing crazy I wouldn't waste my time.

4 oa 15s brah

 

[Based]

Well I've double layered Damp Pro on 2/3 of my roof so far and I've foamed everything up to the middle brace and it's a big difference. I don't have bass right now so it's just a beat test like me hitting the roof but still it's awesome. I have foam stuck in my hair and my hands tho

 

[wone 10+ year member]

great stuff expanda foam works great, been using it for years with no issue or breakage as stated above

 

[Based]

great stuff expanda foam works great, been using it for years with no issue or breakage as stated above

Yah I'm gonna post a before and after tomorrow once I finish the roof up. good stuff. I also have to go get a haircut tomorrow because this **** won't come out my hair.

 

[CSCStang]

Gotta wear a food servers cap man.....

 

[Based]

Gotta wear a food servers cap man.....

lol yeah I know but I didn't think of it getting in my hair. My hands I was aware of but I was just dumb and said **** gloves haha.

 

[wone 10+ year member]

do not get it in your hands that thing is the toughest to get off

 

[hispls 5,000+ posts]

Spray foam is pretty good to keep the headliner from rattling against the roof. Won't do much against roof flexing though. Layers of fiberglass or even better steel would be the cure for flexing metal.

 

[mlstrass 5,000+ posts]

Foam does nothing as it has no strength. Not sure who ever came up with this idea. If it's working for you, I'm guessing your set up isn't loud.

PL Premium, 3/4" hardwood, kitty hair/chop mat/bondo glass. That is all that's needed in 99% of the vehicles out there. If doing a stripper pole then weld in some 1/8" - 3/16" plate first to distribute the load better.

I will say that foam is a giant PITA to clean off when you need to fix someone's hack job and do it right...