Vapor Barrier - Insulation - DIY Chatroom Home Improvement Forum
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Insulation

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Like Tree3Likes
  • 1 Post By Nealtw
  • 1 Post By Bud9051
  • 1 Post By deepsweech
Reply
 
Thread Tools Search this Thread
Display Modes
Old 03-06-2019, 10:33 AM   #1
Member
 
Join Date: Jan 2019
Posts: 30
Rewards Points: 54
Default

Vapor Barrier


Hi,

I live in Massachusetts, doing a basement finishing. 80% below grade poured cement exterior walls are covered by 2in rigid foam and taped sealed. After putting in insulation, do I still need to put a vapor barrier?

Thanks
deepsweech is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 03-06-2019, 10:46 AM   #2
retired framer
 
Join Date: Jun 2017
Location: Fraser Valley BC Canada
Posts: 38,048
Rewards Points: 706
Default

Re: Vapor Barrier


Don't know code there but did you seal the edges, the more air you can keep out of the system the better.
Windows on Wash likes this.
__________________
Do not use flat bottom gables with scissor trusses.
https://www.fema.gov/media-library-d...6/chapter7.pdf
figure 7-14
Nealtw is online now   Reply With Quote
Sponsored Links
Advertisement
 
Old 03-06-2019, 03:52 PM   #3
Member
 
Join Date: Nov 2015
Location: Maine
Posts: 10,695
Rewards Points: 192
Default

Re: Vapor Barrier


Hi deepswitch,
Is that 2" of insulation on the inside or outside?
How old is the basement and what steps were taken to reduce typical moisture and water problems?
In most cases it is best to allow whatever moisture that might get through to evaporate to the air and not accumulate. But we don't know anything about the soil conditions on the outside. Tell us more and maybe a picture or two.

Bud
Windows on Wash likes this.
__________________
I volunteer my help and opinions, but you are responsible for what YOU choose to do with that information.
Bud9051 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 03-07-2019, 08:39 AM   #4
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: Washington DC Metro Area (VA, MD, DC)
Posts: 26,064
Rewards Points: 926
Blog Entries: 41
Default

Re: Vapor Barrier


Quote:
Originally Posted by deepsweech View Post
Hi,

I live in Massachusetts, doing a basement finishing. 80% below grade poured cement exterior walls are covered by 2in rigid foam and taped sealed. After putting in insulation, do I still need to put a vapor barrier?

Thanks

What type of foam did you use. In the vast majority of cases...no. You do not need a vapor barrier.



You DO still want to use the ADA (Airtight Drywall Approach) so as to make sure the warm and moist air is not getting to a condensing surface.



Did you seal up the rim joists?
Windows on Wash is offline   Reply With Quote
Old 03-07-2019, 09:20 AM   #5
Member
 
Join Date: Jan 2019
Posts: 30
Rewards Points: 54
Default

Re: Vapor Barrier


Quote:
Originally Posted by Windows on Wash View Post
What type of foam did you use. In the vast majority of cases...no. You do not need a vapor barrier.



You DO still want to use the ADA (Airtight Drywall Approach) so as to make sure the warm and moist air is not getting to a condensing surface.



Did you seal up the rim joists?
Hi,

Used XPS foam. Yes, all rim joists sitting on the sill plates are spray foamed by the previous owner .
Windows on Wash likes this.
deepsweech is offline   Reply With Quote
Old 03-07-2019, 10:21 AM   #6
Exterior Construction
 
Windows on Wash's Avatar
 
Join Date: Aug 2011
Location: Washington DC Metro Area (VA, MD, DC)
Posts: 26,064
Rewards Points: 926
Blog Entries: 41
Default

Re: Vapor Barrier


No need them. Tape the seams (as you did), frame your wall, insulate (unfaced), and drywall. Detail out the interface between the drywall and the floor to be airtight and make sure all the electrical boxes are airtight as well.
Windows on Wash is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply

Tags
vapor barrier


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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





Top of Page | View New Posts