Return to the Flooring Forum | Post a Follow-Up

 o
Vapor barrier over plywood subfloor?

Posted by cdirmann (My Page) on
Tue, Aug 21, 12 at 15:23

I purchased a laminate floor that I want to use in my house to replace worn carpet. The subfloor is plywood and it is over an unconditioned crawlspace and the home is located in North Florida so humidity/ moisture are a factor. I've heard that the 6 mil polyethelene should not be used as it would trap moisture in the plywood which may lead to rot or mold; however, that is what the manufacturer of the flooring is suggesting.
What kind of vapor barrier/retarder should I use between the plywood and laminate? Would 15# tar paper work? Or is there something more suited to this installation?

Thanks!


Follow-Up Postings:

 o
RE: Vapor barrier over plywood subfloor?

Tough question. I am familiar with what the North Florida environment can do to most anything made of wood, so you are right to be concerned. Moisture passing through a material that then condenses on a barrier is where there could be a problem. Since the crawlspace is unconditioned, then I would assume that you at least have some means for air exchange or venting and that the ground is covered with a moisture barrier.

Very interesting question. Have you consulted with the flooring manufacturer directly about this?


 o
RE: Vapor barrier over plywood subfloor?

I would love to hear what you found out... I am not in North Florida (but the Pacific Northwest). We don't have nearly as high humidity, but we do have a lot of moisture at certain times of the year. I am looking to put laminate over an unconditioned, vented crawlspace as well, and wondering about the use of a vapor barrier between the subflooring and the laminate... Hope you post back if you got an answer!


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Flooring Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here