I'm putting 12x24 tiles for a shower + glass enclosure; is it typical to paint the entire wall with Redgard or just joints that haven't been mortared yet?

1 Answer 1


If you're using Redgard as a moisture barrier (which I assume is what you're doing) you tape and mortar all the joints. Once that's dry, you Redgard over all the cement board and mortar with two coats (1 coat = crack isolation for concrete floors, 2 coats = waterproofing membrane).

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    Agreed. Cementboard will soak up water, so you need to Redgard the entire wall if you're using that as your moisture barrier (if using a different moisture barrier, don't use Redgard or you'll make a "mold sandwich"). Put a bead of silicone in the gap between the floor and the bottom of the cementboard wall or Redgard several inches onto the floor. Alternate vertical and horizontal rolling on the wall. The Floor Elf uses 3 coats of Redgard. floorelf.com/installing-redgard-on-shower-walls-for-tile
    – Paul Price
    Apr 25, 2017 at 0:56

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