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


Thread Tools Search this Thread
Unread 05-26-2006, 09:46 AM   #1
Registered User
Join Date: May 2006
Posts: 7
To be certain I have the order of events

Hi, all........"Newbie" here.

OK, the 1st floor bathroom (tub, toilet, vanity) has been removed to the studs and joists. There is one exterior wall running along the length of the tub. The toilet and vanity are removed, the tub remains. The plan is to tile the floor w/ 8" X 8" tile, the tub walls with 3" X 8" tile, and the ceiling over the tub with 1/2" X 1/2" tile (in 1' X 1' sheets). The untiled walls will be wallpapered.

With all the electrical and plumbing now complete, I will reinsulate the outside wall later today. The exterior wall is brick.

I've read a large number of the posts (on this and other sites) on bathroom tiling, and would like to make certain I have the order of events down correctly from this point forward.....primarily the preparation of the "support materials" that will be used as the substrate for the tile.

1) Install poly-sheeting on the interior edge of the 2 X 4's that form the exterior wall next to tub.

2) Allow the poly to extend below the tub flange, on the tub side of the flange.....securing the poly to the flange using silicone caulk. Any poly that extends beneath the tile to be removed just before grouting the tile.

3) Install the "support panels" that the tile will be adhered to.

On the walls, 1/2" Hardiboard.
On the ceiling over the tub, 1/2" greenboard.
On the floor, 1/4" Hardiboard over 1.25" plywood screwed to 16" O.C. 2 X 10's.

In the tub area, I haven't yet decided if I will run the Hardiboard wall panels to the ceiling, or use greenboard where the Hardiboard stops just short of the ceiling.

5) Install the Hardiboard wall panels "to" (as in sitting upon) the tub flange.

4) Leave an 1/8" expansion joint between abutting Hardiboard panels. Tape the joints and corner seams with mesh tape and the recommended filler.....feathering the filler 6"-8" beyond the tape edges.

5) Apply Redgard to the to-be-tiled Hardiboard and greenboard.....floors, walls, ceiling.

6) TA DA......install the tile.

OK, what did I miss?
Snapper1 is offline   Reply With Quote
Sponsored Links
Unread 05-26-2006, 09:50 AM   #2
Registered User
Oldrem's Avatar
Join Date: Feb 2006
Location: Kenosha, WI
Posts: 1,097
Send a message via Yahoo to Oldrem
If your poly is going over the insullation, make sure you slash any backing on the insullation to avoid a moisture trap.

Lifetime DIYer, Cowboy Action shooter, Gun collector

Oldrem is offline   Reply With Quote
Unread 05-26-2006, 10:05 AM   #3
Registered User
Join Date: Jul 2002
Posts: 30,274
Welcome, Snapper!

1) If you are using polysheeting as your vaporbarrier, it needs to go on any wall surrounding the tub, not just the exterior wall. As Eric noted, defeat any vaporbarrier on your insulation, since this could trap moisture.

2) A few dots of silicone caulk will do, no need for a continuous bead.

3a) If the ceiling joists are not on 12" centers, you may have greenboard sag. Add strapping (1x3s) across the bottoms of the joists on 12" centers if necessary, or switch to 5/8" regular drywall. Regular drywall will be fine here.

3b) What is the maximum unsupported span of the 2x10 joists? If less than 14 feet, no problem.

3c) If you aren't planning on tile above the shower head level, regular sheetrock will be fine. Let me say that better: no need for backerboard above the level of the showerhead, regular drywall is fine.

5) Leave a 1/8" gap between the bottom of the backerboard and the top of the tub flange.

4) Remember to use CBU-rated mesh tape, not drywall tape. The recommended filler is thinset, which you can apply as you tile. Waiting to mud the joints helps avoid creating "speed bumps" on you surface. Your tile will thank you for this.

5) No need for Redgard. You have installed a vapor barrier behind the backerboard, so you'll be creating a moisture sandwich (no vapor barrier is perfect, but Murphy's law will prevail). Water proofing a floor will not protect your house in case of a major flood, since the waterproofing stops at the walls and doorways, but the water keeps going.. If you do wish to waterproof the whole bathroom, skip the vaporbarrier in step 1, but still slit the vaporbarrier in the insulation.

6) Ta-da, part deux!
bbcamp is offline   Reply With Quote
Unread 05-26-2006, 11:47 AM   #4
Registered User
Join Date: May 2006
Posts: 7
Oldrem / bbcamp -

Thanks.....I know, with certainty I would have forgotten to slit the insulation paper.

As for ceiling sag......another good thought. While the original (30 yr) 1/2" ceiling wallboard didn't sag, it also didn't have tile hanging from it. Thanks again!

Rather than 1 X 3's, however, since we're installing recessed ceiling cans, so that I don't have to worry about cutting through the 1 X 3's, I'll support the ceiling in the tiled area in another manner...... probably 2 X 4 cross-bracing (turned wide-edge down) between the 2nd floor floor joists. End result should be the same.

But, "The BIGGIE" was your caution to not use both the poly barrier AND Redgard. If I had given it some thought, the "vapor sandwich" should/maybe have come to mind. With everything else that's going on......probably not.

Thanks again to your both for your time and attention.
Snapper1 is offline   Reply With Quote
Unread 05-26-2006, 03:08 PM   #5
Registered User
Join Date: May 2006
Posts: 7
bbcamp -

A quick follow-up question regarding the taping of the Hardiboard seams.

As I was reading your message, it seemed that you were (at the beginning) suggesting that I should apply the "seaming thinset" and mesh tape at the same time as I was tiling. As I was reading, it seemed (no pun intended) to make sense to me that following this approach would minimize the liklihood of a "speed bump", since the tile would compress the "seaming thinset" uniformly. But then you said, "Waiting to mud the joints helps avoid creating "speed bumps"..... How can that be?

Snapper1 is offline   Reply With Quote
Unread 05-27-2006, 06:55 AM   #6
Registered User
Join Date: May 2006
Posts: 7
bbcamp - I think these are my last follow-up questions


OK, I've worried over the ceiling wallboard and ceiling tile to the point of no sleep last night. Not a good idea, since I've got some help coming over to work with me on the bathroom....and it probably won't be a good idea to fall asleep while he's here. COFFEE, COFFEE, COFFEE!!!

Anyway, I've read posts 'til I'm blue in the face, about the pro's and con's of using greenboard on the ceiling, over the tub, as a substrate for the 1" X 1" (12" x 12" sheets) ceiling tile. In short, I've decided to use the greenboard on a wall in another area of this 5' X 8' bathroom and install regular 5/8" wallboard on the ceiling instead. Before I do, however, a few quick questions:

1) Since 5' of the bathroom ceiling will not be tiled (painted), do I need to install the same poly vapor barrier under (over) the 5/8" wallboard that is immediately over the tub......as I did beneath the 1/2" Hardi I used on the walls that surround the tub? Or, will a good wallboard sealer like Zinzer's to the trick?

For reference, the ceiling for this 1st floor bathroom is supported by 16" O.C. 2" X 10" ceiling joists that are also the floor supports for a heated 2nd floor walkin closet located immediately over this bathroom. There is also an outside-venting 70 cu/ft/min ceiling fan installed in the joist space between the bathroom ceiling and the closet floor.

2) Mastic or thinset to mount the ceiling tile? I'm leaning toward a fast-set mastic (haven't found it yet), due to concerns about the tiles sagging before whatever I use as a bonding agent sets!

3) I know I have another questions, but I'm just too tired to think of it at the moment.

Snapper1 is offline   Reply With Quote

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 05:48 AM.


Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Copyright 2018 John Bridge & Associates, LLC