A Few Quick Questions About Shower Cement Board And Hydro Ban - Tiling, ceramics, marble - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Flooring > Tiling, ceramics, marble


Thread Tools Display Modes
Old 04-27-2012, 07:52 PM   #1
long island, NY
Join Date: Jul 2009
Location: long island, ny
Posts: 382
Rewards Points: 250

a few quick questions about shower cement board and hydro ban

hi all

we FINALLY got our poop together... the plumping is done and our acrylic shower pan is in. So, this weekend, we're putting up the cement board in our shower. a few quick questions:

I'm 90% certain, but just to be sure, I'm supposed to put the cement board a 1/4" above the lip of the shower pan and then fill in the gap with silicone caulking... right? It can't go over the lip because the board would flex a smidge...

the hydro ban instructions are a smidge vague. We put up the cement board, and there will obviously be a seam between 2 boards. Do we use fiberglass tape and skim it with mortar as usual, and THEN use the soaked hydro ban 6" membrane fabric, or do we skip the tape / skim step that is normally done with cement board, and ONLY use the 6" membrane fabric soked in hydro ban over the seam?

lastly, does anyone have some little tips on how to install cement board perfectly plumb in a 35 year old house? a few of the studs are little out of plumb (kinda arched) now. Very subtle, though.

thanks so much for your help


diy'er on LI is offline   Reply With Quote
Old 04-27-2012, 10:06 PM   #2
JazMan's Avatar
Join Date: Feb 2007
Location: Troy, Michigan
Posts: 5,855
Rewards Points: 412

The very best way to handle the flange of the base is to shim out the walls about 1/4" so the board clears the obstruction. Stopping just above the flange also works but you have to make sure to seal that well, and then have faith it'll stay sealed.

Seam the joints with the special fiberglass backer board tape and thinset mortar.

If the studs of not plumb, flat or out of plane, you need to fix that first.

Where did you get the info that you also need HydroBan membrane fabric? Please give us a link or quote.



TILE GUY - retired- TROY, MI - Method & Product suitability consulting.

JazMan is offline   Reply With Quote
Old 04-27-2012, 10:16 PM   #3
long island, NY
Join Date: Jul 2009
Location: long island, ny
Posts: 382
Rewards Points: 250

Did I ever tell you how much I appreciate your responses to my posts?

The membrane fabric thing came directly from the hydro ban instructions from the manufacturers webpage. But now that you mention it, it's only for gaps of I believe 1/4" or more...

I was going to put it on all seems out of super-caution. Probably overkill.

It probably should be put in the corners, though... especially around my shower bench. so I don't need it on flat seams, I guess.

How do I fix those subtle out of plumb studs? The wall in question is not load bearing... Should I plane it down?
(Mercifully, the one load bearing wall is perfect as far as I can tell.)

Last edited by diy'er on LI; 04-27-2012 at 10:18 PM.
diy'er on LI is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1