One-Component Foam Kits Permeability
Although at this point, I decided to go cut/cobble for my rim joist/joist cavities, I just wanted to put this out in case anyone has more insight/info/just wants to know/etc.
I was looking at one-component foams as an alternative to two-component foam kits. Specifically two brands – Vega Bond Insulation and Kraken. They market what appears to be Great Stuff pro stuff to use like one would use two-component foams. It is even applied with the typical foam gun one would use with pro foams – but with a small attachment that acts to “spray” the foam in a fanned pattern like two-component guns.
One-component foams appear to have a mix of closed cell material (percentage in the 70s) and open cell (the rest), as compared to two-component foams which contain a greater percentage of closed cell (high 90 percent).
So my concern was how effective these products would be for my purposes as far as perm rating. Both advertise R-values, but say nothing about perm rating, which for me, being in zone 5, is an important question. Both simply refer to their products as “closed cell.”
Note – I realize that in the cut/cobble method, a one-component (“closed cell”) foam (usually Great Stuff) is used around the perimeter of the rigid foam.
I emailed both vendors, and Vega Bond confirmed that their product is about 75% closed and 25% open, but could not confirm what the perm rating of the product is, and just recommended going about 4 inches when I spoke of being in zone 5.
All Kraken could tell me was that their product is “closed cell,” not mentioning percentage, and that their product has an r-value of 5.66. When I email back about how I was looking for information on the perm rating – not r-value, I received no further response.
Just putting this info out. I don’t know if anyone has any actual experience with these products – especially in cold climate use. Another person made a recommendation of possibly using vapor barrier paint over the foam, but for me, at that point, it’s getting just as cumbersome as cut/cobble.
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