vapor barrier


Old 08-13-14, 04:18 PM
Thread Starter
Join Date: Jan 2013
Location: Canada
Posts: 176
vapor barrier

So I'm redoing my kitchen and tore the drywall down on the exterior wall and noticed the wall had vapour barrier on the inside... That's not normal as far as I know. ny reason why would it be done?
Sponsored Links
Old 08-13-14, 04:25 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 20,532
That *is* normal, especially in a cold climate.
Old 08-14-14, 05:49 AM
Thread Starter
Join Date: Jan 2013
Location: Canada
Posts: 176
I always thought It had to be against the exterior wall.... this is why I used spray foam when I did my basement.. **** is confusing...
Old 08-14-14, 06:06 AM
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 18,657
The vapor barrier, if installed, goes to the warm side of the wall. In cold climates (yours and mine), this is the inside of the wall.
Old 08-14-14, 07:03 AM
Join Date: Oct 2008
Location: New England
Posts: 9,996
mopar, confusing is correct .
Vapor barriers have been redefined as vapor diffusion retarders and classified into different levels, link below. So some materials like spray on foam will still allow some small amount of moisture to pass.

Then there is the new siding job where they add a layer of foil faced foam to the outside before the new siding. To prevent that from becoming a condensing layer they suggest the foam be thick enough that the inside surface will always be above the dew point for each particular climate.

But despite all of the guidance for where to place a vapor barrier, the most important part of the job is sealing all of the air leaks. Taping joints and filling around wiring and plumbing penetration is top priority. Another link on sealing

I hope this helps.

Vapor Barriers or Vapor Diffusion Retarders | Department of Energy

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Display Modes