Insulation barrier needed?

Old 12-20-19, 10:15 AM
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Insulation barrier needed?

Good afternoon!
I am going to be having that attic insulation in my home increased by blowing in 10 inches of cellulose over original 60 year old fiberglass batts. Before adding insulation, the company will be air sealing. I noticed that alot of the paper backing of the original batts is ripping/pulling apart when moving the insulation. My question is, do I absolutely need the paper backing/ barrier on the original fiberglass batts? I read somewhere that any moisture that did come thru the attic would pass thru the batts and cellulose exiting out the ridge vent. I am in Buffalo NY. Any input appreciated!
Merry Christmas!
Old 12-21-19, 04:13 AM
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do I absolutely need the paper backing/ barrier on the original fiberglass batts?
Well, the craft paper acts as a vapor barrier, which is tasked with slowing the transfer of warm, humid air from shedding its moisture when it meets a cool surface.

So, you want a vapor barrier which the paper provides.

We have 100% cellulose insulation and used special primers to act as our vapor barrier.
Old 12-21-19, 05:38 AM
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I do not think it is going to make a lot of difference either way.

Be sure that they install insulation stops before blowing in the insulation.
Old 12-21-19, 06:08 AM
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Yes to baffles in the eaves to maintain ventilation and no to needing the vapor barrier replaced. As Marq1 mentioned the paint you apply to the ceiling will be good enough.

As for air sealing you should be there to watch. Once done there is no way to confirm anything was done. If they (or you) do an air leakage test before and after the sealing you will have some indication. But in too many cases they just jit the easy spots and "good enough. Below is a link to air sealing a home.


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