Vapor barrier floor?
#1
11-21-19, 05:02 AM
Vapor barrier floor?
I thought the idea with a vapor barrier was to literally encase the room in barrier to stop moisture but I never see any plastic under the flooring taped to the wall barrier.
doesn't this allow moisture in through the flooring and into the cavities and walls?
doesn't this allow moisture in through the flooring and into the cavities and walls?
#2
11-21-19, 07:33 AM
Group Moderator
You could use a vapor barrier that way but water could neither move into or out of the room that way. They are typically used to stop water from moving through a surface where it would be normally expected to do so, like a wall exposed to outside air.
#3
11-21-19, 10:44 AM
I got the impression that vapor barriers were often not applied in the joist cavities and therefore moisture could always get in there.
should I be putting barrier against the insulation even in the cavity area against the wall?
should I be putting barrier against the insulation even in the cavity area against the wall?
#4
11-21-19, 11:12 AM
Group Moderator
First, you need to make sure you are code compliant, so I would start with the local AHJ. From what I know, Canada tends to be a little behind current thought of vapor barriers not being necessary so you may have to use one regardless.
#6
11-21-19, 04:48 PM
Same question though...
what use is a vapor barrier on a wall if no-one puts barriers on the floor or in the joist cavities (especially when only partly renovating).
Seems like a huge gap in the house for moisture to enter.
what use is a vapor barrier on a wall if no-one puts barriers on the floor or in the joist cavities (especially when only partly renovating).
Seems like a huge gap in the house for moisture to enter.
#7
11-21-19, 05:56 PM
Group Moderator
Concrete slabs are considered sufficient. If a crawlspace with a dirt floor, then a vapor barrier is recommended.
#9
11-22-19, 02:27 AM
Member
Canada tends to be a little behind current thought of vapor barriers not being necessary
#11
11-22-19, 06:27 AM
The idea of a vapor barrier is to keep your insulation dry.
Fiberglass lose R value when it becomes wet and takes forever to dry out.
Also it helps reduce drafts through the wall.
Fiberglass lose R value when it becomes wet and takes forever to dry out.
Also it helps reduce drafts through the wall.
