# window n door spray foam vs regular



## wantboost (Nov 1, 2011)

whats the difference and what should i use for rim joist cavity


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## Windows on Wash (Aug 30, 2011)

Window and door is low pressure. I prefer to close what should be the smaller gaps. Tends to not pull away as much as the more expanding foams.


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## wantboost (Nov 1, 2011)

Huh????????


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## joecaption (Nov 30, 2011)

Window and door expands less so it does not bow the jambs.
The other is for filling bigger gaps.
I use 2" soild foam for insulating rim joist and use low expanding foam to fill any gaps.


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## wantboost (Nov 1, 2011)

So non window and door


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## joecaption (Nov 30, 2011)

Going to make a big mess and be very expencive to use it to fill that big a void, plus it's bound to have gaps.


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## wantboost (Nov 1, 2011)

joecaption said:


> Going to make a big mess and be very expencive to use it to fill that big a void, plus it's bound to have gaps.


I'm sealing around the rigid foam


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## Windows on Wash (Aug 30, 2011)

Use window and door foam if the gaps are small or seal the gaps with sealant if they are that small.

If they are larger than 1", use the larger gap foam.


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## wantboost (Nov 1, 2011)

Windows on Wash said:


> Use window and door foam if the gaps are small or seal the gaps with sealant if they are that small.
> 
> If they are larger than 1", use the larger gap foam.


What kind of sealant


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## Windows on Wash (Aug 30, 2011)

Anything will work. Just get something that isn't going to stink to Holy Heaven inside the home and make sure it is compliant to work (i.e. not melt) the foam. 

A good acrylic latex will work fine.


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## Gary in WA (Mar 11, 2009)

Read the manufacturers specs on the foam and application. The GS window/door is for windows/doors--- an *open cell *foam. The GS gaps filler is *closed cell*- same as the foam board (hopefully), with more R-value per inch.... which is what you want to prevent condensation on the rim application. http://msdssearch.dow.com/Published...foam/pdfs/noreg/179-07324.pdf&fromPage=GetDoc

http://msdssearch.dow.com/Published...foam/pdfs/noreg/179-07323.pdf&fromPage=GetDoc

Gary


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## Windows on Wash (Aug 30, 2011)

Gary in WA said:


> Read the manufacturers specs on the foam and application. The GS window/door is for windows/doors--- an *open cell *foam. The GS gaps filler is *closed cell*- same as the foam board (hopefully), with more R-value per inch.... which is what you want to prevent condensation on the rim application. http://msdssearch.dow.com/Published...foam/pdfs/noreg/179-07324.pdf&fromPage=GetDoc
> 
> http://msdssearch.dow.com/Published...foam/pdfs/noreg/179-07323.pdf&fromPage=GetDoc
> 
> Gary


Good catch Gary. :thumbsup:

I don't know why I keep forgetting that the Great Stuff is open cell. Also begs the question why it is open cell to be honest, but I am sure cost has something to do with it. 

Nearly every other professional window and door foam out there is closed cell and for good reason (i.e. more R-Value, no absorption, etc.). 

We normally use Soudal foam, but Soudal, OSI, Silco, and I think Hilti (but don't quote me on that one) are all majority closed cell products.

If you are going to be applying this much foam, invest and get a foam gun, some extension straw, and you will be a much happier DIYer. Trust me.


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## wantboost (Nov 1, 2011)

i guess caulk isnt as good as a idea cause it doesnt have a r value


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## Windows on Wash (Aug 30, 2011)

Technically everything has an R-value. If the rigid foam pieces are cut snuggly to fit inside the rim joist area, the R-value offset is going to be minimal. The sealant will have some associated R-value with it as well. Will it be as high


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## wantboost (Nov 1, 2011)

I guess i might just do caulk if they are really snug


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