Is there any problem for the mortar to adhere to Redgard painted Hardie backer? Putting large wall tile 8"x8" on tub surround wall. What mortar is better?

1 Answer 1


There is no problem with thinset adhering to Redgard painted backer. Just make sure there isn't a vapor barrier installed behind the backer board or you'll trap in the moisture. Hopefully, you taped all the seams on the backer board. Use a fortified thinset. Let it set 5 to 10 minutes before applying. Set the tile and wait 24 hours before grouting. Good luck.

  • What are your thoughts on Laticrete Hydro Ban 1 instead of Redgard? And moisture is the reason you use paint or plastic, but not both?
    – Marinaio
    Sep 25, 2019 at 15:02
  • 1
    I'm not familiar with Laticrete. Yes. Redgard paint or plastic vapor barrier but not both. If there was an existing vapor barrier behind the backer board then you wouldn't want to paint with Redgard.
    – JACK
    Sep 25, 2019 at 15:14

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