[tony t]

Hi, I'm framing in a new stall shower, have looked at web sites on the subject and most experts suggest putting a moisture barrier under the cement board. I can see why that would be good. One company, which produces a thick (15 mil) membrane for this application, also shows a detail in which a silicone sealant is used between the membrane and the backer board. There is no mention of brand of sealant, and it doesn't seem they sell it. This is a first for me, and I'd like to learn (from an impartial third party) if this is standard practice.

Thank you

Tony Tammer

[speedball1]

Hi, I'm framing in a new stall shower, have looked at web sites on the subject and most experts suggest putting a moisture barrier under the cement board. I can see why that would be good. One company, which produces a thick (15 mil) membrane for this application, also shows a detail in which a silicone sealant is used between the membrane and the backer board. There is no mention of brand of sealant, and it doesn't seem they sell it. This is a first for me, and I'd like to learn (from an impartial third party) if this is standard practice.

Thank you

Tony Tammer

Hi Tony,
I waited for another expert to jump in as I just pipe in drainage and water and don't build the shower floor or enclosure.
Here's a link that may take some of the mystery out of it. Click on;
http://www.compotite.com/skyblue.html
To see diagrams and instructions. Good luck, Tom

[tommytman]

Yes a moisture barrier is recommended and if you are putting in a shower pan I believe you should run the barrier inside the shower pan liner.

Check johnbridge.com and the forums there. They have some people that really know shower stalls over there.

Tom

[tommytman]

Just to make sure... you said under?? Are you putting the backer board on the floor of the shower?