"Don't use the same installer."

Exactly...................

I would also ask the GC to have the walls furred out or floated to get them flat. You could have the most expensive tile in the world and the most detail oriented installer on the continent but if the SUBSTRATE is not ready for the tile, then it will look nasty.

But I too believe a new installer should be brought in. And to be clear, the tiler is NOT responsible for the floors or the walls being flat or plumb. That is up to the GENERAL CONTRACTOR to get it ready for the tile setter. It's hard to eat what the chef cooks if the dining staff don't set the table.

Could someone clarify what a "rolling shower" is? I have not heard that term before except in prefabricated acrylic type units (not tiled).

I agree that a tile setter is not responsible for walls and floors that are warped, bowed, out of plumb, etc. Unless he/she has been contracted specifically to fix those things, it is not included in a standard install price. Some tile setters will fix those things, but expect additional compensation for that work.

However the same is true for a GC. If it is existing space, not new construction, then the GC is not paid to rebuild a space totally in a remodel situation. It can be done, but at additional cost. Generally one cannot tell in an existing space the extent to which walls and floors are out of plumb or are warped by a visual walkthrough (sometimes you can, but not always). Therefore complete rebuilding of a space, replacing stud walls and/or floor joists are not included in standard scope unless discussed and agreed upon upfront with a customer. Even then, the cost would generally kill most remodel jobs and they would never get done or the additional work would get removed from the scope of the project to get the price back down.

The wording here seems a bit strange to me. Why would a GC "recommend" a tile setter to a homeowner if the GC is responsible for the work? A GC would just schedule his/her tile setter to come in and lay the tile. This is the person he/she would trust to get the project done correctly and the GC would supervise the whole installation. This sort of sounds like the GC was hired to do some work, but not all of it, and that the homeowner is buying part of the materials and supervising part of the work rather than the GC. I would have a stroke if my tile setter and the customer were standing around talking to each other about installation issues.

If you don't have confidence in the tile setter, then a change should be made. It would be hard to move forward for either party and have the working relationship that needs to exist.

Nicely stated Brickwood.

What you just described would be the standard GC/customer relationship. The GC should be responsible for the work. It's great you have a good relationship and lots of trust.

Some things you can do to look at the tile if you really like it. One way that you and your GC can test the tile is to take several pieces and lay them down polished side together - like a sandwich but with nothing between the "bread". What you are looking for is to see if they lay completely flat together or if there is "warpage" in the tile. Test that by pushing down on each corner of the top tile (one at a time) and see if it rocks slightly. Warpage can cause lippage during installation. If would be unusual for a natural stone to have warpage. Also lay out 4-6 pieces of tile side by side with no gaps and make sure all of the tiles are the same thickness. If they are not, then that can cause lippage during installation. If you don't find any issues, then the tile is not at fault.

The issue is then the substrates or the installers. Most likely the substrate. The GC needs to inspect the walls and floors to identify any issues. If there are issues, then a discussion on what it takes to fix the substrates and what the cost would be. (I assume the GC would pay for the new tile and installation.) If the substrates are within reasonable tolerances, then the installation is the source of the problems. If so, the GC and installer should come up with a plan to install new tile for you at their cost.

Good luck. It's always disheartening to have issues, but most things can be worked out. What is a rolling shower??

I don't understand the tile issue. yes it's natural stone, but the tile itself is flat and level, no? If you picked a ceramic tile, the back would be just as smooth and flat as that marble. he's giving you excuses.

you need to start w/plumb walls and level floors.

I have marble on my floors,,,it's perfectly flat. why? because my tile guy made sure to start w/a flat/plumb surface. he floated my walls w/mud.

even though I'm on a slab foundation, he also chose to float the surface w/cement to make sure it was perfectly level.

find a tile guy who can do this. there is no reason you can't have that material. Find an expert tile setter and tell him of your concerns. if the wall isn't plumb, then it needs to be made plumb. if the floor isn't level, then that needs to also be rectified.

you can slide a quarter across this entire floor and it won't get hung up on one tile.

that's how smooth it is. the tile guys I had were worth their weight in gold. Do not use the same installer...they've already proven what they're worth.

In our area, that is called either a zero clearance shower or curbless shower. They are wonderful and are used extensively for aging in place and accessibility. Solves a lot of issues and is a very nice, clean look.

that's called a curbless shower. I sure hope they did it correctly.

A rolling shower, probably means what we call a "roll curb", or "curbless". Now, for the MOST part, your selections are just fine. This is complicated a bit as the extent of the height for the "roll" generally needs to be high enough to allow for door passage if say there is a rug outside the shower and the door needs to clear it. The installer's concerns about the tile on the floor , a 3" hex, could be legitimate if the a 3" tile can't comfortably conform to the required height of the "roll". Other than that, a good tile professional can install that tile to your specifications. And yes, he would work with the GC to make sure that the substrate is proper. If it was ripped to the studs, that should certainly be accomplished. That tile is not what we would consider a "challenge" (other than what we noted about the size of the floor tiles and the potential height of the transition from bath to shower floor). Would add that when working with natural stone, make sure that the installer (a new one) lays it out in advance so that you can agree to the shading and pattern. There are "whiners" in every occupation or craft. "This is the problem, that is the problem". In our industry we all know who they are and avoid them. They are often not capable or they do not take pride in their work such that they have low expectations of themselves. Ask your GC to bring in the "A team" (and do consider the floor tile selection/height of the transition). Have these discussions with the new installer as onsite consults and discussion with qualified professionals will trump online discussions all day long. Good luck with your project.

What waterproofing system is being used?

https://www.ceramictilefoundation.org/homeowners-guide-to-hiring-qualified-tile-installer

He probably said (or at least meant) "roll-in shower"....