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MICHAEL RICE Posted: Nov 19, 2009 01:33 AM	sprayfoam 1inch or cavity fill? i am in the process of receiving bid 1 from a spray foam contractor for my 2200 sq ft basement and was told 1/2 lb spray foam is adequate and allows any condensation that gets thru the barrier back out. when asked about 2lb i was told this was not necessary but if done 1 inch is plenty anymore is over kill! i asked about energy star code and was told this is r10 so asked for a bid with 2lb 1.5 in spray foam. Why not fill the cavity or is 1 inch enough as he stated and is 1/2 pound okay for foundation walls? thanks
Gerry Wagoner Posted: Nov 20, 2009 09:00 AM	Open cell foam is not desirable in situations where saturation may occur. 1.5" of closed-cell foam below grade and 2.5" above grade is sufficient. have fun, oG
Posted: Mar 05, 2010 05:40 AM	olger is wise beyond his beauty... i read of 2" cc being the "safe app" for no condensation in cold climates zones,,,zone 5,,, now i modeled a few different configs for my temps the other morning..not to cold compared to where we were...and had to push the foam app to 2.5 to 3" to put the dewpoint closer to the outside of the structure,,, 1" cc app...you will have the propensity for condensation if conditions allow for such,,doesnt matter if the foam is there or not..it will condense on the next available solid material,,foam,,osb,,block,,cement,,whatever the substrate is,,, all the 1-2" app allows is a more contigeous air barrier,,,but a @ 1.5" or so you have the propensity for a vapor retarding membrane as well,,which will prevent the moisture from drying to the outside,,as it should.. aim high,,shoot low... dude
quentin Posted: Mar 09, 2010 01:16 PM	R10 2lb at 1in? If so, get a different contractor, Then again, looking at the rest of the questions, get a different one anyways. We don't spray open cell below grade since if you do 2 inches it will be enough using closed cell with none of the problems or worries others mentioned.

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Comments

MICHAEL RICE

Posted: Nov 19, 2009 01:33 AM

sprayfoam 1inch or cavity fill?

i am in the process of receiving bid 1 from a spray foam contractor for my 2200 sq ft basement and was told 1/2 lb spray foam is adequate and allows any condensation that gets thru the barrier back out. when asked about 2lb i was told this was not necessary but if done 1 inch is plenty anymore is over kill! i asked about energy star code and was told this is r10 so asked for a bid with 2lb 1.5 in spray foam. Why not fill the cavity or is 1 inch enough as he stated and is 1/2 pound okay for foundation walls?
thanks

Gerry Wagoner

Posted: Nov 20, 2009 09:00 AM

Open cell foam is not desirable in situations where saturation may occur. 1.5" of closed-cell foam below grade and 2.5" above grade is sufficient.

have fun,

oG

Posted: Mar 05, 2010 05:40 AM

olger is wise beyond his beauty...
i read of 2" cc being the "safe app" for no condensation in cold climates zones,,,zone 5,,,
now i modeled a few different configs for my temps the other morning..not to cold compared to where we were...and had to push the foam app to 2.5 to 3" to put the dewpoint closer to the outside of the structure,,,
1" cc app...you will have the propensity for condensation if conditions allow for such,,doesnt matter if the foam is there or not..it will condense on the next available solid material,,foam,,osb,,block,,cement,,whatever the substrate is,,,
all the 1-2" app allows is a more contigeous air barrier,,,but a @ 1.5" or so you have the propensity for a vapor retarding membrane as well,,which will prevent the moisture from drying to the outside,,as it should..
aim high,,shoot low...
dude

quentin

Posted: Mar 09, 2010 01:16 PM

R10 2lb at 1in? If so, get a different contractor, Then again, looking at the rest of the questions, get a different one anyways. We don't spray open cell below grade since if you do 2 inches it will be enough using closed cell with none of the problems or worries others mentioned.

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