I am just about finished installing Hardiebacker in my 30"x60" shower alcove. The front and back walls have Hardiebacker an additional 6" past the shower door where the tile will end. I also have installed two tile-redi niches. I kind of know how to waterproof, just wondering the exact order. I know I need go silicone the 1/4" gap between the acrylic pan and the hardiebacker. I will also apply thinset & alkali tape over all seams and seams where Hardiebacker walls meet drywall ceiling. The Niche instructions say I should fill in the gap between the niches and Hardiebacker with silicone too. I would assume I would eventually use thinset over these as well with tape? I will finish with Redguard - basically coating all walls up to the ceiling using a brush and roller. Thoughs? TIAenter image description here

1 Answer 1


I like the "tilecoach" you tube method. Foam backerboard (hydroban, keri board, wedi).

In your case where you already have the concrete board up, I'd use kerdi membrane or a different fleece membrane.

I don't trust the roll on water proofing. You are relying on proper film thickness. Fleece membrane is just so much more durable and fool proof.

For the kerdi system you'd use unmodified thinset and kerdi band on seams - no silicone.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.