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Discussion Starter · #1 · (Edited)
I recently acquired a small home between Austin Tx and Dallas Tx that has the paper or vapor barrier facing up into the attic. It is stapled like crazy.
I want to add more insulation. Can I cut slits in the vapor barrier and blow in the blow in insulation or do I have to remove the old batts ? Any advice will be appreciated!

Thanks in advance
 

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To add more insulation, remove the vapor retarder paper facing (asphalt coated?) just slitting it won't effect much; "Furthermore, the amount of vapor which diffuses through a building
component is a direct function of area. That is, if 90 percent of the
building enclosure surface area is covered with a vapor retarder, then
that vapor retarder is 90 percent effective. In other words, continuity of
the vapor retarder is not as significant as the continuity of the air barrier.
For instance, polyethylene film which may have tears and numerous
punctures present will act as an effective vapor barrier, whereas at
the same time it is a poor air barrier. Similarly, the kraft-facing on fiberglass
batts installed in exterior walls acts as an effective vapor retarder,
in spite of the numerous gaps and joints in the kraft-facing." From pp.5; http://www.buildingscience.com/docu...por-retarders/?topic=/doctypes/researchreport

Gary
 
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