Hello,
I’ve searched the forums and haven’t found anything that matches my question exactly.
I’m remodeling my bathroom, and I installed Rockwool on the exterior wall. The shower will get Hardibacker with a liquid waterproofing membrane applied.
I’m installing CertainTeed’s MemBrain over the Rockwool on the exterior wall.
Do I install MemBrain behind the waterproofed Hardibacker on the exterior wall of the shower? Or would that potentially trap moisture in the wall cavity?
Thanks in advance!
Replies
The waterproofing membrane on tile wall will block any vapor (probably more so than Membrain) do not need to use the Membrain. You could possibly trap a little moisture w/in the Durarock as it can’t breathe on both sides, I would avoid it. If you have drywall above tile I would use the Membrain on that portion of wall. Big thing to avoid shower moisture is to make sure a proper shower fan is in place w/ proper venting. Also, a timer switch or moisture controlled switch, so you can remove all the moisture in air after the shower.
That makes sense. Thanks!
I wouldn't use either of the products you mention for the tile backer, get Dens-Shield brand tile backer and use it on ALL the walls within the shower area,floor to ceiling, caulk all the seams as you install the panels , i.e. on the butt edges of the sheets as you install them, Not on the face of the backer boards after install. Dens-Shield is a far superior backer board than any cement backer-board!! And it's water-proof!! not water resistant like Hardibacker.
Geoff
Kerdi board is expensive, but completely waterproof all the way through, not just in the coating, also much lighter and easier to cut.
Your Hardi board is as good as the job you do with the liquid membrane. I doubt if the Membrain would hurt behind the Hardi. It is designed to be vapor open at times.