Tile shower tips needed

creiteljorge · 02-24-2013, 09:32 PM

Hi all, I'm installing a porcelain tile standup shower. I have two niches to install and in the niches I want to do a glass mosaic insert.

What type of mortar do you recommend for the porcelain and also for the glass mosaic?

Additionally, for floor and wall porcelain, what size grout spacing can I use? I'd like to keep them thin if possible.

Thanks in advance!

joecaption · 02-25-2013, 12:00 AM

Need to know what sized tiles your planing on using.

**oh'mike** · 02-25-2013, 05:58 AM

use a powdered white modified thinset----

creiteljorge · 02-25-2013, 12:39 PM

The porcelain tiles are 12"x24". The glass mosaic is on mesh backer sheets and the sheets are about 12"x12". The individual glass pieces are probably only 1/2"x varying lengths.

By the way, I'm doing a pebble floor in the shower, not porcelain. Should I use the same thinset?

JazMan · 02-25-2013, 05:01 PM

Absolutely use a premium white modified thinset which is rated for glass tiles or the one recommended by the glass tile manufacturer. Hope the glass is the same thickness as the porcelain tiles, yes?

What are you doing for waterproofing and vapor? Can you tell us how the walls are built from the studs out? How about the floor?

You'd use the same thinset for the floor regardless of whether they're porcelain or stone.

Jaz

creiteljorge · 02-26-2013, 10:12 AM

The shower is constructed in the following manner: Studs, fiber cement board (overkill, I know), Schluter Kerdi System w/ preformed tray and curb.

JazMan · 02-26-2013, 02:30 PM

It would have been nice to know you're using Kerdi since as you should know they want you to use unmodified thinset to install all tile over it. You may have to cheat for the glass though.

Which fiber cement board? It'll probably want to suck the moisture out of the thinset, so you have to compensate.

Jaz

creiteljorge · 02-26-2013, 05:07 PM

I used Certainteed Fiber Cement Board.

I've checked with all of the tile manufacturers and the glass mosaic manufacturer says Mapei makes a white modified thinset specifically for glass mosaic. I need to use that and allow for 100% cure before grouting.

Schluter says to use unmodfied thinset for ceramic tile. However, the porcelain tile manufacturer says to use modified thinset.

Any thoughts?

JazMan · 02-26-2013, 09:30 PM

Quote:

Schluter says to use unmodfied thinset for ceramic tile. However, the porcelain tile manufacturer says to use modified thinset.

And what do you think porcelain is? That's right, porcelain is ceramic.

Schluter wants you to use a premium unmod for any tile over Kerdi and Ditra. Well, except for glass, that's completely different. Every thinset maker makes all the various kinds of mortar. But if the written instructions say to use the Mapei mortar, then do that for the glass.

People have been known to use a modified over Kerdi, it'll work fine, you just void any possible claim if you cared about that.

I haven't used or even seen Certainteed Board locally, just in ads in the trade mags. I think it's similar to Hardie backer. They make several types, Fiber Cement, GlasRoc, DiamondBack GlasRoc, GlasRoc Type X.

By the instructions, looks like Hardie with same warning to damp-wipe just before spreading thinset. People are having trouble with these products cuz they suck the moisture fast.

So fine, but you coulda used regular wallboard with Kerdi.

Jaz

jeffnc · 02-27-2013, 05:46 PM

Correct me if I'm wrong, but I don't think you'd void any warranty with Schluter if you let the modified thinset dry for, say 30 days with mosaic before grouting. That's probably big overkill for something as small as little mosaic, but my point is related to the drying time needed without grout.

JazMan · 02-27-2013, 07:14 PM

You don't need to let it dry that much longer. Actually on walls, I wouldn't worry about anything longer than the normal overnight min. drying time. But being a DIY job, often waiting an extra few days or week is no problem.

When I first stated using Ditra (for floors), I always used a premium modified thinset not knowing Schluter's wishes. Used to finish installing tiles, grout next day and put the appliances back that afternoon. Never a problem.

Jaz

jeffnc · 02-27-2013, 07:45 PM

Quote:

Originally Posted by JazMan

When I first stated using Ditra (for floors), I always used a premium modified thinset not knowing Schluter's wishes. Used to finish installing tiles, grout next day and put the appliances back that afternoon. Never a problem.

That really doesn't surprise me at all, because a well-installed tile job is basically over-engineering anyway for most residential jobs. (The proof of that is all the crappy tile installations that "surprisingly" have never failed.) So your thinset was probably not at full strength, at least for a few months, but it just didn't matter because everything else was probably right.