Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Building & Construction

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Closed Thread
 
Thread Tools Search this Thread Display Modes
Old 04-16-2009, 12:47 PM   #1
Member
 
LeviDIY's Avatar
 
Join Date: Apr 2009
Location: Rockville, MD
Posts: 288
Share |
Question

5/8" Fireboard (Paint) meets 1/2" Cement Board (Tile)


Hey everyone, long time listener, first time caller.

(Not so) Quick and dirty: I'm in a condo. First home, bought 8 months ago. Getting into DIY, finding its a big passion, but I don't have the money and time to get stuff done quickly or buy expensive tools/products . Installed flooring, repainted, minor electrical work, got my DIY feet wet with all that. Now onto the bathroom...

Originally wanted to just clean the tile, strip off wallpaper, switch out vanity top, refinish vanity and change light fixtures... basic stuff. Ripping out the wallpaper, uncovered small mold/mildew problem near the tub.. figured everthing has to go (Built in 1979, so no cement board behind tile, not even greenboard). Ripped out tub/shower surround tile and walls to the metal studs (the board the tile was on was soooo decrepid). Plenty of good Firecode Drywall (required I guess in the condo) on the walls away from the tub, so cut the Firecord drywall at the next stud over, halfway across the stud.

Put up 1/2" Hardibacker around the tub and after using construction adhesive and screwing into the studs (its ON there). Had thought I measured the existing Firecode Drywall at 1/2" but then realized, nooooooo.... its 5/8". Now, I have 1/2" cement board butting up to 5/8" Firecode drywall. You are starting to see my problem.

I read another post/thread on here where the suggestion was to remove the cement board and use shims to meet the 5/8" board. In my infinite wisdom, I didn't really see the problem until AFTER I secured everything (again, its ON there).

Several questions given the above situation:
1) Now, as I plan to do subway tile (3" x 6") all the way to the end of the cement board, and prime/paint the butting Firecode board, is it safe to assume that I can lay the thinset and with the tile on top of it, will close that 1/8" difference in board thickness?

2) Again, assuming I keep that difference (remember, the cement board is ON there), how should I tape the uneven joint? Paper Joint Tape? Fiberglass joint tape? Using thinset/mortar on the cement board half and drywall compound on the Firecode side?

3) On the Firecode edge, should I use a corner bead to protect it, or would you say "Levi, easy... you're going overboard"?

Also, as a follow up to #3, I'm a wee bit annoyed at myself for not doing the ONE thing everyone says: "measure twice, cut/buy/install once" - I'm a perfectionist. So, any encouragement or "Levi, easy... you ARE obsessing over this a bit much, it's happened to me plenty and not a big deal" would be greatly appreciated.


Last edited by LeviDIY; 04-16-2009 at 12:48 PM. Reason: added that I am painting the butting Firecode board
LeviDIY is offline  
Old 04-16-2009, 09:29 PM   #2
Member
 
Join Date: Dec 2008
Posts: 62
Default

5/8" Fireboard (Paint) meets 1/2" Cement Board (Tile)


I've never done anything with fireboard/cement board, but I can tell you I have seen drywall finishers mud 1/8" surface differences more than a handful of times and make it look perfect.

Ininkus is offline  
Old 04-16-2009, 11:10 PM   #3
Member
 
Join Date: Feb 2009
Location: Seattle, Washington
Posts: 344
Default

5/8" Fireboard (Paint) meets 1/2" Cement Board (Tile)


On point #3, corner bead will do more harm than good if there is any chance for getting it wet. As for the rest your screwed. (not really). This is what I would do. First I would tape the inside corners of the cbu with cbu tape and thinset. It's a special tape, not just the fiberglass stuff. Next, I would take a 1/4" x 1/4" square nothched trowel (doing 1 wall at a time) cover the cbu only with thinset then smooth out the notches. This should give an even coat of 1/8" over your cbu. Next tape over the flats using the same tape and thinset. A thin coat of thinset on your drywall isn't going to hurt a thing. Last, I would Redquard over the thinset with 2 coats.

Last edited by Mop in Hand; 04-16-2009 at 11:19 PM.
Mop in Hand is offline  
Old 04-17-2009, 10:07 AM   #4
Member
 
LeviDIY's Avatar
 
Join Date: Apr 2009
Location: Rockville, MD
Posts: 288
Default

5/8" Fireboard (Paint) meets 1/2" Cement Board (Tile)


Ininkus - yeah you are right, except I'm no professional

Mop In Hand - you actually scared me for a second with the screwed comment. What you are describing makes sense.. I'm a bit concerned about getting that initial layer of thinset smoothed out well enough... but just to clarify: once I get the thinset as close to equal with the butting drywall board, tape those again (In other words, the initial tape UNDER the thinset layer, then again above it?)? ALso, not familiar with Reguard... is that available at HD/Lowes or should I try a local building supply?

Thanks both for the responses... even just the initial responses help me breathe a bit easier
LeviDIY is offline  
Old 04-17-2009, 10:38 AM   #5
Member
 
Join Date: Feb 2009
Location: Seattle, Washington
Posts: 344
Default

5/8" Fireboard (Paint) meets 1/2" Cement Board (Tile)


No, do not tape them twice, tape the inside corners and flats of the cbu first. After you have added the 1/8" thinset then tape where the drywall and cbu meet. Sorry about the mis-spell. It should read "Redquard", available at Home Depot or Lowes. It's a waterproofing membrane in the tile section. Use a magnesium trowel to smooth out the notches (works better than a regular float). Be sure your thinset is dry before Redquard.
Mop in Hand is offline  
Old 04-17-2009, 10:50 AM   #6
Member
 
LeviDIY's Avatar
 
Join Date: Apr 2009
Location: Rockville, MD
Posts: 288
Default

5/8" Fireboard (Paint) meets 1/2" Cement Board (Tile)


OK ok... now I think I'm picturing it... get the 1/8" of thinset along the WHOLE cement board... I was thinking just at the joining of the drywall and cbu. so, thinset across the board... smooth it out... tape with redquard... 2 coats... then the regular thinset layer to lay tile on?

Sorry to be such a pesky questioner... gotta be sure I get ya on this And I really appreciate the advice.
LeviDIY is offline  
Old 04-17-2009, 06:25 PM   #7
Member
 
Join Date: Feb 2009
Location: Seattle, Washington
Posts: 344
Default

5/8" Fireboard (Paint) meets 1/2" Cement Board (Tile)


Yes, except "tape with Redguard?" Redguard is a membrane that is rolled on. (I use a foam roller) Cbu tape is also available at HD. Good Luck
Mop in Hand is offline  
Old 02-09-2010, 12:45 PM   #8
General Contractor
 
Join Date: Feb 2010
Location: Portland, OR
Posts: 85
Default

5/8" Fireboard (Paint) meets 1/2" Cement Board (Tile)


If you plan on covering the entire cb and only the cb with tile, could you look around for slightly thicker tile, or create a border, either with some sort of edge tile or wood or pvc trim over the 5/8 rock?

I think I would be looking for a way to avoid building up the 1/8th difference. No matter how it's done, there is going to be a transition with a reveal. Why not build it into your design, taking advantage of it to create a cleaner and easier install?

Just a thought.

Good luck,

Rory

RDG Read Development LLC
Portland, OR
Rory Read is offline  
Old 02-09-2010, 09:40 PM   #9
Newbie
 
Join Date: Nov 2009
Posts: 28
Default

5/8" Fireboard (Paint) meets 1/2" Cement Board (Tile)


I like rory's idea of an accent to hide it, (something dark) For future reference all firerock is 5/8"
naehring2000 is offline  
Old 02-09-2010, 09:41 PM   #10
Member
 
Join Date: Jan 2009
Location: South of Boston, MA
Posts: 17,248
Default

5/8" Fireboard (Paint) meets 1/2" Cement Board (Tile)


This thread is from April 2009 & was bumped by a spammer

Scuba_Dave is offline  
Closed Thread

Tags
bathroom tile question, cement board, drywall, joint, joint compound


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
concrete paint removal before tile installation SR996 Flooring 1 03-21-2009 07:31 PM
Cement Board and Drywall Champy Remodeling 2 01-24-2008 03:32 PM
Rotten cement - skim coat or board? BradG Building & Construction 1 11-25-2007 02:25 PM
1/4" or 1/2" cement board? kemerick Flooring 4 09-14-2007 11:42 AM
Backer board vs. plywood for tile underlayment allpraisebob Flooring 4 01-07-2007 07:44 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.