Tiling a ceiling in a steam room [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


View Full Version : Tiling a ceiling in a steam room

12-21-2016, 02:51 PM
Okay! First time asking a question here but this forum came highly recommended....so here it is:

I am tiling in a steam room. I have sealed the entire room with red guard. Then I attached backer concrete board everywhere.....the room is tight and I am about to tile the ceiling first.

I am using 4" X 28" ceramic tiles (looks like wood) for the ceiling.... My question is....What is the optimum width for the grout line on the ceiling tiles?

Any instruction or suggestion would be greatly appreciated...


Sponsored Links

12-21-2016, 03:05 PM
Welcome, Kenny. :)

I have sealed the entire room with red guard. Then I attached backer concrete board everywhere.I'm wondering just how you did that. A fella normally would apply the RedGard to the inside of the shower walls and, in the case of a steam shower, to the ceiling and probably the pan, depending upon how the pan was constructed. Do tell us more.

1. Is your ceiling sloped the required 2" per foot?

2. Is this a residential shower or a continuous use steam shower?

3. As for the grout joints, that's usually decided by the person writing the checks. The tile industry recommends that the joints be at least three times the difference in size between the largest and smallest tiles in the layout with the minimum being 1/16th of an inch. Are your tiles rectified?

My opinion; worth price charged.

12-21-2016, 03:38 PM
Hi Kenny, welcome to the forum. :)

Yes, please clarify. If you did Redguard and then fastened cbu, you must have penetrated the Redguard with your fasteners. Or maybe I'm reading your sentence incorrectly.

12-21-2016, 05:53 PM
That is exactly what I did as per the guy that sold me the red guard at Lowes.
I red guarded the entire area, then I attached the concrete backer board on top of that. yes the screws penetrated the red guard. The salesman told me that would be in significant and the holes would seal when the board was tightened to the wall. Apparently not heh?

Yes...the ceiling and shower floor have proper pitches.

So should I re red guard over the backer board before I mortar and tile?

12-21-2016, 06:09 PM
Hi Kenny. Exactly what did you apply the Redgard to? The studs?

Lowes and Home Depot are not very good at giving advice.

12-21-2016, 06:27 PM
I applied the red guard to the existing drywall, and the green board I used to patch some areas i had cut out. after the red guard was in place, walls and ceiling, I screwed up concrete backer board.

should i red guard over the backer board?

12-21-2016, 06:43 PM
Drywall is not an appropriate substrate to apply redguard to. Cement Board Units are appropriate substrates for redguard applications.

12-21-2016, 06:56 PM
thank you

12-22-2016, 10:43 AM
take it down and start over and dont speak to anyone at the big box stores

HooKooDoo Ku
12-22-2016, 11:40 AM
As a fellow DIYer, I would have to agree with the others... start over.

1. Rip out all the CBU you've installed and all the drywall under it to the studs.

2. Since you're at the stud level, this is where you want to make sure everything is a flat as can be. Ideally you have studs that are strait, are mounted strait, and are level with one another. A 4' level is a really nice tool to help determine if studs/joists are flat and flat relative to each other. If you can place the level against any three studs/joists with out any gaps or rocking, then you've got a flat plane to begin with. If you don't you need to do something to make it flat.

Of course the easiest way to make things flat if they are not is to simply plane/sand down any high areas until everything is flat... but that's only going to be an option for things are only a tiny bit out of flat.

If insulation isn't in the way, you can easily nail sister studs/joists that protrude just a little. By adjusting how much each protrudes, you should be able to create a flat surface and then attach the CBU to the sisters.

If you have insulation between the studs that you don't want to mess with, then you need to do something on the surface to create a flat surface. I wish I had a simple suggestion for this situation. It's what I faced, and decided to nail rows of thin strips of wood across the studs (about 12" -16" between rows). I used various thicknesses of spacers behind the strips so that when I was finished, the surface of all the strips were flat. However, when I went to hang the CBU, I found I couldn't use the standard CBU screws. They were too short. I had to find some alternate screws that would be compatible with the concrete in the CBU and long enough to penetrate the CBU, strips, and spacers, and still be long enough to penetrate the original studs by at least an 1" or more. The only screws I could find at the time was that Home Depot carried a line of SPAX that were safe in concrete and long enough for the job. But then, because they were not the standard CBU screws with ridges that help cut into the CBU to help them flush mount, I had to find a pair of concrete screws to drill counter sinks (first a thin one to cut a pilot hole, then a very fat one drilled to just the right depth for a counter sink). It was a pain, so I hope you or the pros in the forum can give you a better suggestion if you are facing this situation.

01-15-2017, 01:25 AM
oh man i'm a DIY about to do my own master and it sounds like you got alot of bad info.

Rip it all out to teh bare studs and if you're going redgard, then CBU to the stud and then redgard. Hookoodoo is on point