Installed wrong insulation thickness in my garage


Old 03-01-16, 02:52 PM
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Join Date: Mar 2016
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Installed wrong insulation thickness in my garage

I'm about halfway done with insulating my garage and realized I got the incorrect insulation...thinking I had 2x4 studded walls, I grabbed the 3 1/2" Kraft rolled insulation. I actually have 2x6 studded walls. Will the extra room for the insulation to expand affect the stated R-value of the insulation? Should I remove what I have done and start over with 5 1/2"? The 3 1/2" is R13 and I live in MN.

Last edited by Mattjdeboer; 03-01-16 at 02:57 PM. Reason: Adding info
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Old 03-01-16, 03:37 PM
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Welcome to the forums! Since it is a long term investment and insulation is important, I would pull out the R13 and install R19.
Old 03-01-16, 03:49 PM
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I agree 100%.
Should have been noticed before it was even installed.
Old 03-01-16, 04:50 PM
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Location: New England
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Fiberglass insulation needs to be encapsulated on all 6 sides even though we see it open on top in our attics. leaving the space empty behind the 3.5 will result in a much lower r-value so i agree with Larry and Joe, pull the 3.5 and install the full depth.

Old 03-01-16, 09:47 PM
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Join Date: Mar 2016
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Thanks everyone! Upon further wall is 2x4 and the other is way of cutting cost I guess 👎🏼 that is where I was thrown off. Good news is I only need to replace about 12 feet of the wrong stuff since it was the wall that was still in progress.

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