Vapor Barrier?


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Old 05-24-18, 04:46 PM
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Vapor Barrier?

This is in a house, where a storm tore off some of the shingles which caused leaks into the ceiling. I live in Georgia so not much cold here but higher humidity.I am considering using Rockwool that is unfaced in the ceiling.
Would I need to put up a vapor barrier above the drywall? Thanks
 
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Old 05-25-18, 01:14 AM
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Would I need to put up a vapor barrier above the drywall?
Vapor barriers always go on the "warm" or conditioned side.
 
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Old 05-25-18, 05:30 AM
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No, your paint will be a class III vapor retarder... it's all you need.
 
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Old 05-25-18, 05:35 AM
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When I worked in fla all the new houses got a plastic vapor barrier on the walls but never the ceilings. Here in tenn it's rare to see them use plastic on the walls. IMO the main thing is to caulk any openings in the drywall [elec boxes]
 
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Old 05-25-18, 06:34 AM
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And in the deep South, the vapor barrier is on the outside... which is the warm side... but not the conditioned side.
 
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Old 05-25-18, 07:53 AM
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That may have changed but when I worked in fla in the 70's & 80's the vapor barrier was always on the inside, just behind the drywall. Not sure how they do it know as I moved in 91.
 
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Old 05-25-18, 06:55 PM
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Yes, current thinking has changed, which is why vapor barriers have fallen out of favor as being a "requirement" in all but the coldest climates.
 
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Old 05-26-18, 03:02 AM
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Thanks X when I worked in fla it was part of the building code but when I moved to tenn hardly anyone did it .... but codes/enforcement are laxer here than anywhere I've lived.
 
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Old 05-26-18, 04:35 PM
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Thanks guys. Marksr, what caulk do you recommend for electric boxes?
 
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Old 05-27-18, 02:58 AM
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Most any latex caulk should be fine.
 
 

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