(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 4 of 4

Thread: Slab top-side vapor control Airspace approach

  1. #1
    DIY Senior Member diyfun's Avatar
    Join Date
    May 2011
    Location
    MA
    Posts
    131

    Default Slab top-side vapor control Airspace approach

    Read the "READ THIS BEFORE YOU DESIGN,BUILD OR RENOVATE" doc and found above recommendation on page 13 or 19, Or view it here (click me). Many of you here, including Dana, seems like "poly + foam + plywood" approach for basement floor. Above approach is "dimpled + foam + plywood".

    The dimpled is more expensive than poly. is it worth to spend several hundreds more?
    Attached Images Attached Images  
    Last edited by diyfun; 02-26-2012 at 05:48 PM.

  2. #2
    In the trades Dana's Avatar
    Join Date
    Jan 2009
    Location
    01609
    Posts
    2,720

    Default

    I haven't seen any good science that would indicate a need for dimpled membrane rather than 10-mil poly as a capillary break when retrofitting a slab. The wicking potential of either poly or XPS is extremely small, and no-wicking/drying toward the basement==no mineral depletion of the concrete. The slab itself doesn't "need to dry", and encouraging moisture migration through the slab only degrades it. The additional benefit of having an air-space between the extremely low-permeance non-wicking poly sheeting and the concrete is academic.

    Dimpled membranes may be useful under ceramic or wood flooring with NO foam with damp slab, where a rip in a poly sheet might allow some wicking of moisture into the ceramic, staining it. But with an inch of (no-wicking low-permeance) XPS that's not a likely scenario.

    If the water table is occasionally high and you regularly get wet spots or efflorescence on the slab, use a concrete sealer on it before the poly + foam.

  3. #3
    DIY Senior Member diyfun's Avatar
    Join Date
    May 2011
    Location
    MA
    Posts
    131

    Default

    Do I need to leveling the floor before put poly+ foam?

  4. #4
    In the trades Dana's Avatar
    Join Date
    Jan 2009
    Location
    01609
    Posts
    2,720

    Default

    If you were planning to use a cement based floor leveler it'll bond better and have fewer cracking issues if you apply it to the slab, and not on top of the foam.

Similar Threads

  1. Vespin II seat side to side play
    By magnumip in forum Toilet Forum discussions
    Replies: 2
    Last Post: 12-08-2011, 02:01 PM
  2. Help! Toto ultramx rocking side to side- does it need to be shimmed?
    By DIYjulie in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 3
    Last Post: 09-24-2011, 08:56 AM
  3. Tub drain and stack side by side... how to connect
    By louk in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 2
    Last Post: 07-12-2008, 08:55 AM
  4. Backup power DC/inverter approach
    By alternety in forum Electrical Forum discussion & Blog
    Replies: 22
    Last Post: 03-13-2008, 12:35 AM
  5. Kitchen aid Superba side by side fridg...
    By chris fox in forum Remodel Forum & Blog
    Replies: 0
    Last Post: 07-30-2007, 04:40 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •