Cement board vs purple gypsum board for small repair

Discussion in 'Shower & Bathtub Forum & Blog' started by Hughpe, Feb 11, 2019.

  1. Hughpe

    Hughpe New Member

    Joined:
    Jan 24, 2017
    Location:
    Pennsylvania
    Water leaked from corner of tub- from taking showers-onto green board drywall and ruined it. I’ve taken steps to mitigate the leakage but have no doubt that will occasionally get wet. It’s a small repair but probably a pain. Would cement board or purple gypsum board be a better substitute for the rotted drywall. Thanks
     
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Joined:
    Sep 2, 2004
    Occupation:
    Retired Systems engineer for defense industry.
    Location:
    New England
    The purple stuff tends to have a water resistant coating on it, but the guts are still gypsum and you'll be poking holes in it to attach it!

    CBU won't be damaged by being wetted. To get the surface prepped, consider setting mud versus the premixed stuff. YOu don't have much time to install it, but it won't soften again if it gets damp like the premixed stuff. Mix small batches.

    FOr reference, I'd take a level and check the rim of the tub. It should have a slight slope to it into the tub and not slope outside. It could just be the shower curtain isn't well positioned, or the door, if it's configured that way, but more often than not, it's the tub was not leveled properly during installation.
     
  3. Sponsor

    Sponsor Paid Advertisement

     
  4. Stuff

    Stuff Active Member

    Joined:
    Mar 7, 2013
    Location:
    Pennsylvania
    The bigger issue isn't the wallboard but the waterproofing that failed. Cement board is OK to get wet but will let water pass through and you'll eventually have a moldy mess in the wall. Lots of 1950's bathrooms around here were covered with glued on plastic tiles as they didn't think people would actually use the shower. Then a new family moves in and tiles start popping.
     
Similar Threads: Cement board
Forum Title Date
Shower & Bathtub Forum & Blog Novice looking for help with sealing inset cement board Nov 25, 2018
Shower & Bathtub Forum & Blog Question about leaving gap between shower floor and cement board wall Dec 11, 2017
Shower & Bathtub Forum & Blog HELP!!! Contracted has put cement board with a giant hole in it... looks very very wrong Jun 23, 2017
Shower & Bathtub Forum & Blog Liquid membrane over cement board Jun 21, 2017
Shower & Bathtub Forum & Blog Cement board in shower renovation Jun 18, 2017

Share This Page