I have question regarding vapor barriers when installing a metal roof over existing shingles. There seems to be some debate on whether the layer of existing shingles will act as a vapor barrier. We currently have a project home that has a metal roof installed over an existing layer of shingles. This metal roof has been in place for approximately 6-8 years and we do not see any signs of issues with the decking in the attic. Seems like there are no issues, but want to make sure we aren’t overlooking something.
Guest User
2015-06-29 10:02:48.000000
"The place for a true vapor barrier is below the ceilings, not in the roof assembly." - below the ceilings - DOES THIS MEAN IN THE LIVING AREA?
Guest User
2015-07-28 02:18:32.000000
Thank you, Mr. Novotny.. That's what I thought Mr. Miller meant, although that is not what he wrote. i.e. On top of the ceiling, on the bottom of the ceiling joists, on the top floor.
Guest User
2015-07-29 08:39:12.000000
There should, in my opinion, be a layer of underlayment between the old shingles and the metal roof. Do you have anything or is the metal direct on top of the old shingles.
The place for a true vapor barrier is below the ceilings, not in the roof assembly.
Todd Miller
2015-06-29 10:23:03.000000
Sorry for my confusion -- I do see where my fingers got ahead of my brain above!
Todd Miller
2015-07-29 11:03:14.000000
No.
It means that if you are going to have a vapor barrier, it needs to be towards the warm wall.
Eric Novotny
2015-07-28 07:10:42.000000
Once you start talking about ceilings vs. attic vs. roof...its easy to get things twisted around.
Warm side placement is where it goes, if you even require one.
It should be on the backside of the conditioned space drywall.