Batt Insulation Width


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Old 08-07-21, 04:30 PM
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Batt Insulation Width

I have to replace some insulation in an attic. The bays vary...some of the width are 12.5, 13.5, 14, 14.25, 14.5 14.75 and finally 15. Most are in the 14-14.5 range.

At what point should I trim the edges to fit the 15" batt width? i.e if the width is 14.5" should I attempt to trim off the 1/2"? It would be easy to do as I have the equipment and table....just wondering if the small amount of scrunching is something to be concerned about?

Thanks!

Addl: This will be faced batt insulation
 
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Old 08-07-21, 04:46 PM
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Once it gets to about 13.5 you might want to roll the facing back in order to trim it. But if it's up to 1" too wide you can cram that. And you will want to just roll / fold the flap of extra Kraft paper up in order to staple it... don't cut it.
 
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Old 08-07-21, 05:59 PM
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How critical is it to staple it? I'm not "too" concerned about the vapor barrier. I'll still fold the paper up into the bay.

Edit: Just found this....sounds like it's not too important.

https://www.certainteed.com/resource...n_Products.pdf
 

Last edited by Tumble; 08-07-21 at 06:15 PM.
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Old 08-11-21, 06:03 PM
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So I'm looking at this

https://www.homedepot.com/p/Owens-Co...RF40/202585898

In its description it says it is for "2 in. x 6 in. walls (interior/exterior ), floors" but nothing about ceilings. I've got 2X6 rafters. Make me nervous it doesn't mention ceilings, is there something I don't know? Can I use it for my ceiling?
 
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Old 08-11-21, 07:16 PM
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The insulation doesn't care where you put it. The kraft facing always faces the interior in cold climates.
 
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Old 08-11-21, 08:49 PM
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So I think I figured out why they label it that way. It's R19. Their R38 is labeled as attic insulation. I'm covering the R19 with perpendicular layer of unfaced R30 so yea, I'm good to go with the R19 between the bays. Thanks X!
 
 

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