dcsimg

Vapor Barrier over an old slab

Here you'll find a wide range of discussions on old-house topics.

Moderators: TinaB, Don M, Schag, oldhouse

Vapor Barrier over an old slab

Postby scootermcrad » Wed Jan 25, 2017 9:09 am

Hi everyone!

I've posted this question in other places, but it seems there is often a lack of understanding that old homes didn't use today's standards and advancements in building technology. This seemed like a better place.

Our house was built in 1937. An addition was built in the 1940's on a concrete slab. There is obviously no vapor barrier or insulation between the grade and the slab. The slab was also built with quite a slope (for its original purpose). In order to put down my hardwood floors (reclaimed oak from a home built in 1935), I'll be putting down pressure treated sleepers, insulation between, and AdvanTech subflooring. I know I will need to isolate the slab from the new floor system. But what is the appropriate material?

SO! The question is: what should I use for a vapor barrier and what is the best way to combat air bubbles and voids below the vapor barrier? Voids will inherently lead to mold/mildew, which would be bad.

I have a roll of 6 mil poly vapor barrier. Can it simply be put down with adhesive to prevent bubbles? Tile adhesive? Or do I need to consider a product like Fortifiber Moistop Ultra 10 mil?

Any help would be really appreciated! I'm right smack in the middle of this and need to start getting the slab prepped for the floor system.

THANK YOU!
scootermcrad
 
Posts: 2
Joined: Wed Jun 27, 2012 7:39 am
Location: Concord, NC

Re: Vapor Barrier over an old slab

Postby Joel » Wed Feb 01, 2017 6:22 pm

I did the same thing. Just put down 6 mil poly and started flooring over that. No need for adhesives, etc. You really don't care what happens under the poly. It really reduced moisture in my basement.
Joel
 
Posts: 195
Joined: Sun Dec 07, 2003 11:36 am
Location: Central New York

Re: Vapor Barrier over an old slab

Postby scootermcrad » Wed Feb 08, 2017 7:57 am

Joel wrote:I did the same thing. Just put down 6 mil poly and started flooring over that. No need for adhesives, etc. You really don't care what happens under the poly. It really reduced moisture in my basement.


Thank you! I appreciate the reply!
scootermcrad
 
Posts: 2
Joined: Wed Jun 27, 2012 7:39 am
Location: Concord, NC


Return to General Discussions Forum

Who is online

Users browsing this forum: Google [Bot] and 6 guests