Shower renovation help requested....

[Karen Vanek]

Hi. I am 2/3 of the way done with my bathroom tear down/ rebuild. I have installed 1/2 of my cbu (hardie board). I am using onyx collection pan and wall panels. The onyx collection people claim you do not need to waterproof under their panels.... I just wanted to know if you all agree with that. I had been planning on using redgard over the cbu. However I have since found out that it doesn't stick to hardie board. I guess if you use a thinned down primer coat that will stick and the redgard will stick to that. However the silicon (used to put the onyx panels up) will not stick to redgard. So you know have to put a cement patch mix over the redgard.... I am just thinking that with all these coats and chemicals that don't stick to each other , I might be better off to leave the cbu as is and just put the panels up as the onyx collection people tell me to do. However one of the walls of the shower is an exterior wall , the other side being the garage. Do i need some vapor barrier or is the waterproof panel enough? Thanks.

 

[WorthFlorida]

I would remove all of the Hardie Board, since it's contaminated and use DensShield. I used this on my bathroom shower walls and it worked. Years later I had to remove the wall on the other side of the shower due to a leak in the valve body. The DensSheild has no signs of mold or deterioration. The drywall I removed to gain access did. Between the DensShield panels I covered the seams with fiberglass epoxy for 100% water proof.

DensShield looks like regular drywall but the gypsum is impregnated with fiber glass or other material, the cover is water proofed and the backing is a fiber glass like material. You can take a piece of it and place it in a pail of water. It floats for days and take it out and its completely dry. The panels are also very stiff, cut it like drywall and it is lighter in weight. Use the same screws as for hardie board, not drywall screws.

It is really good stuff with built in water proofing. I think because it is never seen on home TV remodeling projects, no one know about it.

https://www.lowes.com/pd/DensShield-0-49-in-x-31-9-in-x-59-9-in-Gypsum-Backer-Board/1000223857