CBU over mud or in mud pan? [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


View Full Version : CBU over mud or in mud pan?

Jim L
04-20-2008, 05:13 PM
I've seen the diagrams for proper mud pan and shower installation on this site and I am wondering if setting the CBU directly into the mud pan allows water to wick up the wall. Would you recommend installing the CBU about 1/4" above the mud pan to help isolate the wall from the pan? Wouldn't this be a better practice?

Jim L

Sponsored Links

04-20-2008, 05:59 PM
how would you anchor the lower part of the CBU to the wall and stop movement ?

Jim L
04-20-2008, 06:14 PM
I would nail the board two to three inches from the lower edge. Will this be a problem?


04-20-2008, 06:22 PM
with cement board you can do it either way.No nails that low in pan(nothing lower then 3" above curb)

Jim L
04-20-2008, 06:37 PM
Thanks Eric, is there a preferred way?


04-20-2008, 06:45 PM
I prefer to hang the cbu,then add the mud up to the cbu.

04-20-2008, 07:30 PM
Hold the CBU up off the pan liner about 1/2 -3/4 inch and then force a little mud back under it when you mud the floor. This will keep it from going in or out and holding it up off the pan should keep it from wicking. Make sure the weepholes are open, block them so the mud can't fill the holes. :)