insulation and vapor barrier helped needed!

Old 09-06-15, 06:14 PM
Thread Starter
Join Date: Sep 2015
Posts: 1
Upvotes: 0
Received 0 Upvotes on 0 Posts
insulation and vapor barrier helped needed!

Hi everyone, after reading quite a bit I decided to join and make my first post. Right now Im in the middle of turning a small building into a semi heated and cooled work shop.

The building is 20x11. It is 2X6 studs on 12 centers. It has 1x6 tongue and groove paneling nailed directly to the studs.

I have bought r-19 faced kraft insulation that I have to cut in half to fit the 12 stud gaps. What im concerned about it vapor barriers vs vapor retarders. I have some poly barrier also on hand. I was thinking sense it is tongue and groove that maybe I should put some ply over studs then my insulation with facing toward the room? But would that cause moisture to get through the kraft insulation barrier and then trapped behind the poly? So then the moisture is trapped and cant go either way but get absorbed into the insulation? Or what happens when vapor comes through the poly from the outside and then into insulation and trapped by the batting on the insulation?? As you can tell Im having some very conflicting ideas please help!
Old 09-06-15, 06:54 PM
Temporarily Suspended
Join Date: Jul 2008
Location: NY
Posts: 10,265
Upvotes: 0
Received 0 Upvotes on 0 Posts
Is there concrete block or plywood, on the other side of the studs?
Old 09-06-15, 07:04 PM
Join Date: Oct 2008
Location: New England
Posts: 9,460
Received 47 Upvotes on 43 Posts
Hi Ng and welcome to the forum.
Since you are in a heating dominated climate you should locate any vapor barrier (only one) on the warm side of the framing. With 12" oc spacing you will struggle to fit that faced insulation in neatly and neatness does count.

If you try to keep the Kraft faced insulation it will not give you a very good VB. My advice would be to pick up some 24" (22.5) unfaced so when cut in half it will fit properly between your 12" spaced studs. Are you sure they are 12" oc ??? With unfaced insulation you then cover the entire wall with plastic, being neat and sealing all air leaks.

In the summer with cooling, yes the VB is on the wrong side, but the moisture issue is much less critical and the wall assembly can still dry to the outside.

Air sealing the wall assembly is one of the most important steps.


Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: