Ceramic Tile Advice Forums - John Bridge Ceramic Tile

Welcome to John Bridge / Tile Your World, the friendliest DIY Forum on the Internet


Advertiser Directory
JohnBridge.com Home
Buy John Bridge's Books

Go Back   Ceramic Tile Advice Forums - John Bridge Ceramic Tile > Tile & Stone Forums > Tile Forum/Advice Board

Sponsors


Reply
 
Thread Tools Search this Thread
Old 12-11-2004, 05:18 PM   #1
RichTile
Registered User
 
Join Date: Feb 2004
Posts: 35
Backerboard next to drywall and wicking?

(Part of Rich's Shower Saga series)

I'm planning on having a shower stall with no returns (if that's the right word), so two of the opposite shower walls simply continue on as bathroom walls without any "vertical curb", so to speak. This appears to be OK, and I can get a door to handle this.

However, I need to figure out both where to do the joint from CBU to drywall, and how to finish it so that water doesn't get wicked to the drywall. If I finish it with drywall joint compound, some of the drywall mud will be in the wet area and that obviously can't be good.

The walls (slate) are only to be tiled in the shower. I plan to bevel the edges of the slate just outside the shower wet area because that's the only finish I can think of that would make sense with slate. It will transition to a painted wall. I'm thinking of slightly overlapping the drywall with the (12") slate, so that the joint is hidden. I don't know if there will be wicking issues, though (as this will be very close to the door location). I also don't know if it's OK to have part of the tile unbonded. I'm thinking an inch tops here.

I know slate is not recommended in a shower. That's a subject for the next thread. :7

There is 2X4 "vertical blocking" if you will (essentially a stud on the flat, at the curb location). This is obviously how I want to install the door (at about the center of the curb, I guess?), and where I want to make the joint--as close to the outside of the curb I can get and not have fasteners too close to the drywall edge.

Do I have an alternative? Do I need to worry about wicking? It seems lots of people just extend the CBU out to the next stud, but CBU makes a lousy surface to paint on and I'd like to end the wall tiling essentially where the shower does (probably don't have the tiles, either).

Diagram of section of 2x4 on flat (close to actual size!), and what I'm talking about:


Code:
                approx. CBU/Drywall joint location
                      .
    (Dry Side         .         approx. door location         (Wet Side 2x4 edge)
    2x4 edge)      :  .
       |           :  .               |                                |
       |           :  .                                                |
       |           :  .               |                                |
       |           :  .                                                |
       |           :  .               |                                |
       |           :  .                                                |
       |           :  .               |                                |
       |           :  .                                                |
       |           :  .               |                                |
       |           :                                                   |
                   :
                   :
              Approx. tile edge
Thanks,

-Rich (no, I will not draw that again)
RichTile is offline   Reply With Quote
Sponsored Links
Old 12-11-2004, 06:14 PM   #2
Davestone
Florida Tile & Stone Man
 
Join Date: Apr 2004
Location: Naples Fl.
Posts: 22,687
If you extend the cbu to the next stud, you just finish over it with joint compound to make a smooth surface for paint. If you stop it short, just use thinset and cbu joint tape. I couldn't figure the drawing out, don't feel bad, i'm no better. I would prefer a doubled up stud to a flat one.
__________________
Dave



http://Davestonestile.com
Davestone is offline   Reply With Quote
Old 12-11-2004, 06:17 PM   #3
Steven Hauser
STT Owner
 
Steven Hauser's Avatar
 
Join Date: Mar 2003
Location: Greenville, South Carolina
Posts: 5,156
I think I agree with Dave, can you bring the CBU out to the next stud where it is dry?
__________________
Clean
Sealed
Safe
Products and Practices Perfected™
STT Sealers with Attitude!®
Steven Hauser is offline   Reply With Quote
Old 12-11-2004, 06:57 PM   #4
Davy
Moderator -- Mud Man
 
Davy's Avatar
 
Join Date: Jan 2003
Location: Princeton,Tx.- Dallas area
Posts: 28,637
Hi Rich, it's best to keep all your questions on one thread instead of starting a new one for each question. It makes it easier to keep up.
__________________
Davy

www.davystephenstile.com
Davy is online now   Reply With Quote
Old 12-11-2004, 09:46 PM   #5
RichTile
Registered User
 
Join Date: Feb 2004
Posts: 35
Quote:
If you extend the cbu to the next stud, you just finish over it with joint compound to make a smooth surface for paint. If you stop it short, just use thinset and cbu joint tape.
Oh--I hadn't thought of that. I have skim-coated an entire wall, and I'm not really keen to repeat the experience. I suppose it's only about 16"x8'. It's of course rather difficult to keep the skim coat as flat as the drywall--at least for me.

The shower stall is, of course, just under three feet, so extending it makes me use a sliver of CBU if I lay it out vertical. Not a huge issue, it just gets trickier for layout (obviously, I don't *actually* just add a sliver...) There's not a lot of studs to play with in three feet, but nothing to say I can't add my own. It's of course the wall with all the plumbing, etc in there.

I wasn't aware that a 2x4 on flat was not preferred. The existing one at the door location is pretty well in there at this point, it's actually attached at a few places to the stud right next to it. And the curb is tapconned in front of some deck screws that secure the bottom of it. So, I'd rather leave it, but I'll keep in mind it could use reinforcement.

At the junction of CBU to drywall is there any reason I would need to use two studs together? I assume not, since you make a CBU-CBU or drywall-drywall joint on one stud without (much) difficulty all the time.

Quote:
Hi Rich, it's best to keep all your questions on one thread...
No problem, but with the amount I type I was figuring that nobody would read to the end if I tried to put it all in one! Guess I should keep it short and save on bandwidth for you guys...

-Rich
RichTile is offline   Reply With Quote
Old 12-12-2004, 09:41 AM   #6
bbcamp
Registered User
 
Join Date: Jul 2002
Posts: 30,274
Add a stud where you need it.
bbcamp is offline   Reply With Quote
Old 12-12-2004, 12:01 PM   #7
Mike2
Registered User
 
Join Date: Nov 2003
Location: LaConner, Washington
Posts: 13,694
Hi Rich.

Just another option to consider - A drywall "J" bead placed along the transition joint to CBU should provide all the isolation needed to prevent wicking. And I agree with Dave re. avoiding the use of framing members (in this case 2X4's) laid flat. Double up the studs there with some 1/2" blocking inbetween, much stronger.
Mike2 is offline   Reply With Quote
Old 12-13-2004, 01:08 AM   #8
RichTile
Registered User
 
Join Date: Feb 2004
Posts: 35
J-bead! If it means less joint compound work, I'm all for it. I suppose it might rust if it gets too much moisture.

As for the 2X4 on flat, thanks for bringing it up. It's already somewhat sistered to an ajacent stud, so I may just add another stud to the other side.

But let me tell ya, I've done lots of other improvement projects (including a simple tile floor), but I can't toenail to save my life. Are there any tips or alternate methods to adding a stud? It's an issue for adding a niche as well. I just really suck at it.
RichTile is offline   Reply With Quote
Old 12-13-2004, 07:02 AM   #9
bbcamp
Registered User
 
Join Date: Jul 2002
Posts: 30,274
Nail a block to the sill and top plate, then nail the new stud into the block.
bbcamp is offline   Reply With Quote
Old 12-13-2004, 05:20 PM   #10
Randy B
Registered User
 
Join Date: Nov 2004
Location: Minnesota
Posts: 60
Another idea...

Rich... I did a fiberglass/acrylic shower at my house and used the plastic J bead for the transition to the drywall. (the shower unit was made to attach directly to the studs and have the drywall butt up to an edge that runs all the way around the unit.) I used the J bead on the dry wall, then I primed and painted the drywall with a semigloss paint and finished with a thin bead of silicone between the shower and J bead and again between the drywall and J bead.
No problems so far (6 months)...
__________________
Randy B
Randy B is offline   Reply With Quote
Reply

Stonetooling.com   Tile-Assn.com   National Gypsum Permabase


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Forum Jump


All times are GMT -6. The time now is 03:02 PM.


Sponsors

Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright 2014 John Bridge & Associates, LLC