# Taping Batt Butt Joints



## SeniorSitizen (Sep 10, 2012)

I will be insulating an area with 24 x 48 kraft faced batts. The butt joints paper will be taped. Is there a special recommend tape made for that application or would aluminum tape work just as well?


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## Bud9051 (Nov 11, 2015)

Hi SS, I'l ask why you are worried about those joints?
Vapor barriers have been become far less important than when first invented and in many climates they are not necessary at all. Besides being a lot of work, there is little gain. I don't have the reference but the discussion was about slitting the kraft paper to eliminate its vapor retarder properties when not desired. The article said, if the slits amount to 10% of the area then the VB performance is reduced by 10%. Given that your wall will probably be covered with drywall (guessing) and painted that would be 10% of the 10% moisture that passes very slowly through the paint.

The tape, probably not necessary.
Bud


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