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Ceiling insulation

jereli's Avatar

Join Date: Nov 2012
Posts: 54

02-20-16, 08:54 PM   #1  
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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chandler's Avatar
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02-21-16, 03:23 AM   #2  
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.

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02-21-16, 06:23 AM   #3  
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.

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Tony P.'s Avatar

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02-21-16, 07:50 AM   #4  
If you want to add insulation that takes you above the joists, extend the height of the joists.

jereli's Avatar

Join Date: Nov 2012
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02-21-16, 07:51 PM   #5  
Thanks. It looks like ill just have to go with r19.

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