Hello everyone. I have a question regarding thinset for travertine. I will be laying large travertine tiles on my shower walls which are cbu. The tiles are 12" by 24" and was wondering what would be a good thinset to use since these are so large? They are also light coloured tiles so I am assuming I would need a white thinset. I am going to be installing 1" mosaic tiles for the shower floor and am also wondering do I do the walls or the floor first? My washroom floor will be 16" travertine tiles on top of ditra and I have white non modified kerabond for these floor tiles, I hope this is a good choice. Thankyou.

Ditra with white Kerabond, then the tiles is perfect for the floor.....IF. Your joists are stiff enough for stone tiles, and you have a double layer subfloor. You of course will use a modified thin set to install Ditra to the plywood.

I guess you're using the traditional method on the shower floor. http://www.ontariotile.com/preslope.html Is there a vapor barrier behind the CBU or are you applying a surface waterproofing membrane?

I don't like working on newly installed tile, so I do the floor last. I usually leave the first row of wall tiles for the end so that the wall tiles overlap the floor tiles. Makes for a better looking joint, takes more time too...but.

Jaz

Thanks for the reply Jaz. I will be installing the travertine on a concrete floor and the cbus on the shower walls have vapor barrier behind them. I thought I should redguard the walls because some of the travertine tiles I have are porous and only grout will be filling some of the holes. Do you know of a good thinset to set these tiles 12" by 24" on a vertical wall? And as a sidenote have you ever heard of redguard being visible when laid underneath a very light coloured tile? Thanks for the info.

Either use the redgard, or the vapor barrier behind the CBU, but not both. I would rather have redgard on the walls.

Your choice of thinset depends on what is available to you. Laticrete Multipurpose or Mapei Ultraflex 1 or 2 are good choices if you shop at Lowe's. Versabond is good from Home Depot, provided you can get it in white.

I would use a 1/4x1/2x1/4" trowel, or alternately a 1/2" square notch trowel for tile that size. Some of those size tiles have a bit of crowning to them, however since it's travertine, it should be pretty flat. Might be worth your trouble to check and see if they are. You might get by with a 1/4x3/8x1/4" trowel if they're flat. Main thing is to get good coverage.

I've never heard of Redgard showing through tile. Doesn't mean it won't, though.

Thanks for the information guys. I will try and find the mapei at the tile dealer nearest me. There is no lowes only Rona and home depot near me and my home depot has to be the worst in existence for information and stock. Thanks.

I have only herd of one RedGard problem on a natural stone install.
The photos I saw were showing a definite red discolouring in the grout mostly, along with some of the stone.
I don't know what the outcome was, but it was speculated that the RedGard was not completely dry prior to setting the stone, causing bleed thru.
I personally can't imagine how that was possible, but you never know.

Rona should have White Kerabond.

Thanks alot for the info guys I will let you know how it turns out.