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Old 03-29-2012, 02:55 PM   #1
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Foam Insulation in Rafters

I have 1/2lb foam insulation spayed on my attic roof rafters. Thickness is 6-7" since I cannot see my 2x6s. foam was also spayed on walls of attic space but my builder didnt put any blown in insulation or batt rolls on top celings joists. I live in south Texas where it gets bout 100-105 degrees outside. Will putting unfaced R30 benefit me in any way on energy bills. There is no ventilation on the attic.


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Old 03-29-2012, 04:53 PM   #2
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You apparently agreed to have a conditioned attic, which means it is living space, just like your living room. There is no point in adding insulation between conditioned rooms, unless you want to reduce noise a somewhat. If they used open cell foam, it probably needs to be painted w/ a vapor retarding paint. Talk to the contractor about which they used. If they said nothing, it is probably closed cell.,, and other places have good resources on this type of installation.


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Old 03-29-2012, 06:27 PM   #3
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6-7" of open cell probably isn't enough in this case.

You should have at least and R-30 across the roof or at least 8-9".

You could add insulation across the floor if you so desire and it would have some impact.

+1 on checking out building
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Old 03-30-2012, 03:38 PM   #4
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Are you saying to put batt insulation directly under the foam or on the ceiling joist where the sheetrock is? Another ? would I use unface batt or faced batt because I know the foam is already acting a a vapor barrier.
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