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Is vapor barrier required?
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Re: Is vapor barrier required? By  RLGA

Posts: 0

2/12/2009 7:47:00 PM

I''d have the roof cross section analyzed by a mechanical engineer or a building enclosure consultant to determine which direction the vapor drive is most prominent. They should then be able to determine where, if at all, condensation will occur. You want the vapor to be stopped prior to the point where condensation will occur.

It is likely the vapor drive in your situation will be from the exterior to the interior. Since metal is a vapor retarder, the metal roofing will prevent exterior water vapor from entering the building, provided all joints are properly sealed.


Re: Is vapor barrier required? By  pkorb

Posts: 0

2/13/2009 10:58:00 AM

I agree an analysis would a good idea, but in this climate,the vapor drive would go both ways depending on the season , and for my money,the safest bet would be no vapor barrier.


Re: Is vapor barrier required? By  rlmarch

Posts: 0

2/13/2009 6:20:00 PM

Just a suggestion for a source of good information, contact the insulation manufacturer and get their specific recommendation for that location.
They do have a tendency to know more about the application of their product than anyone to avoid litigation.


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