View Full Version : 1/2 inch Hardibacker with no vapor barrier ... oops

08-23-2010, 01:55 PM
Hi everyone... A few months back I installed an acrylic shower pan and then 1/2 inch hardibacker on the walls and used Laticrete spectra-set to embed my slate tiles. I taped and thin set all seams.

I was given so much conflicting information regarding vapor barriers that I decided not to use one based on the advice of a contractor who told me that since none of my shower walls were external they needed to breath. I am now seriously questioning that advice but my shower is already tiled and I really don't want to rip it all out.

I use a high quality stone sealer which I can see is causing the water to bead-up on the stone and grout.

Currently, the shower is being used about twice a day but that usage will drop significantly once our full shower is complete (with vapor barrier... learning from my mistakes http://www.terrylove.com/forums/images/smilies/frown.gif)

My question is, how bad is this? Is it guaranteed shower failure or mold? Is there anything I can do besides ripping out the tiles to fix this?

08-23-2010, 02:56 PM
Industry standards call for a vapor barrier behind or on top of the cbu. Hardiebacker won't be harmed by the moisture, but if there's any that gets back there, it could give you problems with the structure behind (i.e, the studs). At this point, I'd leave it alone, keep the sealer intact by recoating as recommended on the product instructions, and consider wiping the walls down after finishing so there's little chance of lots of moisture saturating and wicking into the backer. I'd run the ventilation fan during and after a shower for a bit to remove excess moisture in the air as well.

Next time, check out www.johnbridge.com (http://www.johnbridge.com) for help on tiling. There are a lot of pros (and talented DIY'ers) there willing to answer tile specific questions and set you straight.

08-24-2010, 06:01 AM
Ok great. Thanks for the advice...

This really is a great forum and I've learned a lot from it ... hopefully at some point I can pay it forward ... although I don't know if anyone wants advice from me right now considering my vapor barrier blunder :)

08-24-2010, 11:25 AM
Lots of showers last a very long time constructed the way you have yours. It's just better if you have a vapor barrier behind to keep moisture out of the structure. How much gets back there depends on lots of factors. Take care of the ones you can: ventilation, ensuring the structure is intact (grout, caulk, sealer, etc.), and minimize the standing moisture by wiping down the walls (especially the lower area opposite the showerhead), and it is likely to last a very long time.