Ceiling insulation


Old 02-20-16, 08:54 PM
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Ceiling insulation

I have 2x6 ceiling joist and a section of my attic has some plywood. From some of my research online I looks like r30 is what I should be putting in my attic here in southern California. But my joist are 2x6 and r30 is about 9 inches thick I believe. Do i just compress is down to the 2x6 size where I have attic floor? Or should I use r19 in that where my attic floor section is and r30 everywhere else where there isn't floor? Reason I ask is because I was told it's not good to compress the insulation.

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Old 02-21-16, 03:23 AM
chandler's Avatar
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If you want insulative qualities you can't compress the insulation. Basically you will attain R30 without the flooring, or you will have to install R19 in order to have the flooring.
Old 02-21-16, 06:23 AM
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Closed cell spray foam is about an R6 per inch. That will get your R30 in the 5.5" space of your 2x6's. Down side is it's expensive.
Old 02-21-16, 07:50 AM
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If you want to add insulation that takes you above the joists, extend the height of the joists.
Old 02-21-16, 07:51 PM
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Thanks. It looks like ill just have to go with r19.

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