# taping kraft paper seams



## jimmy21 (Jul 2, 2008)

Is tape required on seams on fiberglass batts?


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## joecaption (Nov 30, 2011)

Never once seen it taped.
Going to need more info.
Wall, ceiling, basement, ECT.


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## jimmy21 (Jul 2, 2008)

Walls and ceiling in normal new construction. Ceiling is what I'm referring to though. All the seams on the walls are on the studs. The seems on the ceiling are every 4'.


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## joecaption (Nov 30, 2011)

4' spacing is not "normal construction" except on the west coast.
Normal anyplace else would be 24 or 16" on center.
Spacing that wide I would have had it spray foamed or at least used solid foam board so there was no gaps.
Max on fiberglass is 24" wide so there's always going to be a gap between the two pieces even if you added tape.


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## jimmy21 (Jul 2, 2008)

4' in the other direction. 2' spacing of the rafters with 2'x4' batts


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## joecaption (Nov 30, 2011)

Then why use Batts, use rolls instead so there's less or no seams.
Keep in mind no one here is there, just trying to understand the logic.
Common practice is to install the insulation then install a 6 mil. plastic vapor barrier.


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## jimmy21 (Jul 2, 2008)

Wouldn't that make a double vapor barrier and trap any moisture that found its way in?


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## ToolSeeker (Sep 19, 2012)

Yes if you use faced.


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## Gary in WA (Mar 11, 2009)

jimmy21 said:


> Is tape required on seams on fiberglass batts?


No tape; bottom of page 5;http://www.buildingscience.com/docu...por-retarders/?topic=/doctypes/researchreport

Rips and tears are ok, as the material is area weighed. Tight joints, no rounded corners, full contact with drywall, no side-stud stapling of the tabs (inset).
Gary


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## jimmy21 (Jul 2, 2008)

That document was a very interesting read. Thanks for that


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