To Vapor Barrier Or Not To Vapor Barrier, That Is The Question. - Building & Construction - DIY Chatroom Home Improvement Forum


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Building & Construction

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

Reply
 
Thread Tools Display Modes
Old 09-18-2009, 12:17 PM   #1
Newbie
 
Join Date: Sep 2009
Posts: 4
Rewards Points: 10
Default

To Vapor Barrier Or Not to Vapor Barrier, That Is The Question.


Hi,
I'm redoing a shower. I'm using 3/4" moisture resistant foam sheet insulation on the exterior block walls and furring strips over that (same way it was). Then cement board and a waterproof membrane. The problem I'm having is the foam that I took off had foil on both sides. I'm assuming that is a vapor barrier. I haven't seen any foam insulation that has foil. And the insulation companies have been useless in telling me if I need a vapor barrier or not. I'm not worrried about codes, just doing it correct. Do I need a vapot barrier? By the way the house is in central Florida. Thanks.

Advertisement

joegambler is offline   Reply With Quote
Old 09-18-2009, 12:47 PM   #2
Member
 
Join Date: Feb 2009
Location: Seattle, Washington
Posts: 344
Rewards Points: 250
Default

To Vapor Barrier Or Not to Vapor Barrier, That Is The Question.


Adding a vapor barrier on both sides of the cbu will create a moisture sandwich. install one or the other but not both. I am assuming this is an exterior wall.

Advertisement

__________________
Work is for those who can not fish.
Mop in Hand is offline   Reply With Quote
Old 09-18-2009, 01:54 PM   #3
Member
 
concretemasonry's Avatar
 
Join Date: Oct 2006
Location: Minneapolis/St. Paul, Minnesota - Latitude 45.057 Longitude -93.074
Posts: 3,824
Rewards Points: 2,136
Default

To Vapor Barrier Or Not to Vapor Barrier, That Is The Question.


some types of foam bords need a foil barrier to eliminate off-gassing that will reduce the insulation value in the end.

Dick
concretemasonry is offline   Reply With Quote
Old 09-18-2009, 02:25 PM   #4
Newbie
 
Join Date: Sep 2009
Posts: 4
Rewards Points: 10
Default

To Vapor Barrier Or Not to Vapor Barrier, That Is The Question.


Hi,
I don't understand your reply. The foam I took out with foil on both sides was there originally from the builder. I'm not adding a vapor barrier to both sides of the cement board. The waterproofing membrane I'm using on top of the cbu is to waterproof the shower under the tiles. I just need to know if regular 3/4" foam board with no vapor barrier on the exterior wall is correct. Thanks.
joegambler is offline   Reply With Quote
Old 09-18-2009, 02:28 PM   #5
Newbie
 
Join Date: Sep 2009
Posts: 4
Rewards Points: 10
Default

To Vapor Barrier Or Not to Vapor Barrier, That Is The Question.


Hi,
From what I understand from your reply is that the foil doesn't necessarily make it a vapor barrier. O.K., I still need to know if no vapor barrier or yes. Thanks.
joegambler is offline   Reply With Quote
Old 09-18-2009, 10:40 PM   #6
Member
 
Join Date: Feb 2009
Location: Seattle, Washington
Posts: 344
Rewards Points: 250
Default

To Vapor Barrier Or Not to Vapor Barrier, That Is The Question.


No foil is needed. You do not want a foil/moisture barrier if you are using Redgard or the like on top of your cbu.

Advertisement

__________________
Work is for those who can not fish.
Mop in Hand is offline   Reply With Quote
Reply


Thread Tools
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Basement Renovation Question KUIPORNG Remodeling 234 08-26-2008 09:19 AM
hrv question indep HVAC 3 07-17-2008 11:39 PM
Basement vapor barrier question rob7young Remodeling 2 04-13-2008 10:10 AM
New service Question Onytay Electrical 1 10-24-2007 06:47 AM
One furnace question and one thermostat question lh0628 HVAC 4 10-11-2007 11:17 PM




Top of Page | View New Posts