Jerry Simon Posted November 27, 2012 Report Share Posted November 27, 2012 Your thoughts on such? Quote Link to comment Share on other sites More sharing options...
David Meiland Posted November 27, 2012 Report Share Posted November 27, 2012 What would you normally expect as the vapor barrier--poly on the framing, kraft on fiberglass batts, VB primer on the ceiling? Quote Link to comment Share on other sites More sharing options...
Jerry Simon Posted November 27, 2012 Author Report Share Posted November 27, 2012 What would you normally expect as the vapor barrier--poly on the framing, kraft on fiberglass batts, VB primer on the ceiling? Yes Quote Link to comment Share on other sites More sharing options...
Tom Raymond Posted November 27, 2012 Report Share Posted November 27, 2012 How deep was the cells? Once you get to R-45 or so (15" applied, 13.3" settled) it pretty much is an air barrier. Quote Link to comment Share on other sites More sharing options...
Jerry Simon Posted November 27, 2012 Author Report Share Posted November 27, 2012 Once you get to R-45 or so (15" applied, 13.3" settled) it pretty much is an air barrier. That's what I've been told. Can't recall ever seeing such, though (no vapor barrier). Usually see fiberglass batts w/VB covered with a layer of cellulose. Quote Link to comment Share on other sites More sharing options...
kurt Posted November 27, 2012 Report Share Posted November 27, 2012 I think it's better without if its deep. Quote Link to comment Share on other sites More sharing options...
John Dirks Jr Posted November 27, 2012 Report Share Posted November 27, 2012 I never see VB if its loose fill only. Quote Link to comment Share on other sites More sharing options...
hausdok Posted November 27, 2012 Report Share Posted November 27, 2012 Hi, Cells is a very good vapor barrier in and of itself. It allows water vapor to diffuse slowly through it and evaporate on the cold side of the insulation, without allowing a lot of heat bypass leakage, and while doing a good job preventing wind infiltration. As long as you've got good attic ventilation on the cold side of the batting you'll be good. Using a vapor barrier on the ceiling plane would work but if it were on top of the insulation - say in a layer of kraft-paper-faced fiberglass batting - it might cause moisture issues within the insulation if the vapor trying to pass through that batting is being cooled to dewpoint. ONE TEAM - ONE FIGHT!!! Mike Quote Link to comment Share on other sites More sharing options...
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