Insulation and plastic barrier?


Old 01-13-19, 05:47 AM
Thread Starter
Join Date: Sep 2004
Location: New York
Posts: 514
Received 0 Votes on 0 Posts
Insulation and plastic barrier?

I have a new build addition and putting faced insulation in the walls. Should I also put plastic vapor barrier over the insulation for extra draft protection? Sometimes you get those little draft leaks coming through the top and bottom sill plates, thought maybe with the plastic it would help keep some of it out, I live in a cold high wind area.
Sponsored Links
Old 01-13-19, 06:10 AM
Marq1's Avatar
Join Date: Sep 2016
Location: USA MI
Posts: 6,577
Received 377 Votes on 352 Posts
There is so much discussion, some conflicting, some personal, regarding vapor barriers (barriers and retarders) that you will find.

A barrier (plastic) does not allow anything to pass and that can cause issues unless the house is specifically designed to handle the excess moisture that will be generated.

Personally, if you have an exterior wrap (tyvek). have addressed all the openings (air infiltration) and proper insulation (with kraft paper) I would never install plastic!.
Old 01-13-19, 08:26 PM
Group Moderator
Join Date: Oct 2004
Location: WI/MN
Posts: 19,580
Received 94 Votes on 83 Posts
The paper is somewhat of a vapor barrier and general thought is not to use two, as that can trap moisture. Air sealing, prior to insulating, unfortunately, was probably what you should have done to the walls.
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
Ask a Question
Question Title:
Your question will be posted in: