Green/Cement Board Overlapping Tub Flange vs Leaving Gap Between Board and Flange

Discussion in 'Shower & Bathtub Forum & Blog' started by DavidSeon, Sep 24, 2012.

  1. Freddie

    Freddie New Member

    Messages:
    54
    Location:
    Ottawa
    Hi John,

    Not so keen on using drywall or Denshield (which has a layer of drywall) in the shower even with topical coverage...just in case. Cement board seems the obvious and proven alternative with hydroban on top. I will have a vapour barrier behind the cement board. Should water get into the cement board it's not getting into the wall. Now the question is where will that water go if the bottom of the backerboard is sealed at the base / at the junction to the shower acrylic base? Looks like it will run down the backer board and collect at the bottom with no place to drain to.

    Would it make sense to just not seal the bottom of the backerboard with hydroban , nor silicone the gap between the tile and the shower pan so that water candrain into the shower pan?
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,319
    Location:
    New England
    Don't use a topical waterproofer with a vapor barrier behind the sheet goods...one or the other, not both.
  3. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

    Messages:
    4,827
    Location:
    North Vancouver, BC
    Tough design call.

    Grout breathes.

    Your install is no different than a tub install.


    JW - "When it's perfect. It's Good Enough."

    www.No-Curb.com - my blog site on Barrier Free, No Curb, No Dam and Hobless Showers
    (604) 506-6792 jfrwhipple@gmail.com
    Last edited: Dec 12, 2014
  4. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

    Messages:
    4,827
    Location:
    North Vancouver, BC
    .
    Last edited: Dec 12, 2014
  5. johnfrwhipple

    johnfrwhipple Bathroom Design & Build - North Vancouver, B.C.

    Messages:
    4,827
    Location:
    North Vancouver, BC
    Green EBoard Shower Update

    A couple years back we got a bad batch of GreenEBoard.

    Was not very happy with what I found.

    I later stumbled upon WonderBoard Lite - it is now my goto backer board.


    JW - "When it's perfect. It's Good Enough."

    www.No-Curb.com - my blog site on Barrier Free, No Curb, No Dam and Hobless Showers
    (604) 506-6792 jfrwhipple@gmail.com
    Last edited: Dec 12, 2014
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