A tiler who is truly concerned about doing a proper job will want to maintain ownership of the entire process. -preslope -membrane -tiling mud -tile Not having a preslope under the membrane and allowing multiple subs to share the creation of the shower floor can create problems down the road. If you have problems, why are their problems? Who "created" the leak? When I've been called in to arbitrate, I've never seen anyone take ownership of a problem. Never. Each has always has pointed at the other. So, can pans be split between subs and can they turn out well? Sure. But EVERY failed pan I've seen has either been constructed improperly and/or the job was split between two subs. Every time. If anyone want to install your membrane on the flat, walk away. If anyone normally installs the membrane on the flat, but they'll install it on a slope just for you, walk away. They'll probably dork up the details. Find someone who does it right each and every time. Shower pans are easy to do correctly. But they are so difficult to repair when they've failed. As to the preformed trays, Schluter does have a 72" square presloped tray. I don't know what the width of your shower is, but these trays can be cut down. There are details to be considered when cutting a tray down, mostly in regards to the bottom course of wall tile. Nothing at all difficult to overcome, though. Mongo

Covering Wedi board ($$$$$) with Kerdi($$$) isn't what I would consider to be the best use of construction funds. Alright, I'll simplify...it's a huge waste of money. Huge. If this is not a steam shower, then use Wedi alone, or use Kerdi over cement board. If this is a steam shower, then use Kerdi over cement board. Wedi isn't appropriate in a steam shower. If your guy likes the lightweight membrane covered "boards" and you need a vapor barrier, then there is always Kerdi Board, that is appropriate in a steam shower. But that is pricey too. Then simplify the drains. Wedi drain for Wedi system, Kerdi drain for the Kerdi tray. (Or Kerdi drain set into a sloped mud pan.) I don't know of any compatibility studies regarding Wedi Drain with Kerdi membrane. That doesn't mean it won't work. That doesn't mean it's doomed to fail. But it is a combination that wouldn't be covered by anyone's warranty. Substantial? I do think 1/2" cement board is more substantial or stiffer on the walls than the 1/2" membrane-covered foam boards, unless you get into the thicker boards. But then your cost increases and your shower shrinks in size.

Just morter the glass in between two tiles on each side and grout it. Waterproofing a shower has nothing whatsoever to do with the tiles....their only job is to make it look pretty. Waterproofing is plastic or tarpaper attached to the studs before the cement boards go in or is a membrane applied to the face of the board before tiling.

I'd prefer that more grout had been left in the joints. They look dished out a bit too much, where too much grout was removed during the cleanup phase. I'd have preferred the grout to be more flush with the face of the tile. Looking closely at the first two photos, the darkened grout lines are all parallel to one another. In the first photo you can see the wet grout lines are all parallel to the edge of the drain. That leads me to believe that the "uphill" edges of the tiles are acting like mini dams and holding water, they are preventing water from easily flowing downhill to the drain. The second closeup photo, you see the same effect. All the damp grout lines are again parallel to one another. Again, to me that reflects a drainage issue. Not necessarily with the amount of floor pitch, but with the grout lines being so dished out that they hold water and slow drainage. Marble is porous and can absorb water. With the grout lines being a bit too raked out, the edges of the marble hexes are exposed. Water held against the tile edge can lead to absorption into the marble. The crack in the grout in that second photo, you also wrote that there are other cracks. That's usually a sign of too much water used in the grout mix, or that sanded grout should have been used instead of unsanded. Unsanded should be used in joints less than 1/8" wide. Cracks can also indicate movement in the floor, but that shouldn't be an issue with a properly set Kerdi Tray. As far as him having used a preformed Kerdi-Tray, if he did, it appears that is was certainly cut down in an awkward manner. The drain is no where near centered in the shower. So if he did some filling here and there with mud or thinset to even out the floor pitch or edge elevations, that could have be part of the problem. But that's supposition on my part. About the only other thing I could question is that often times with small tiles, when the sheets are set into the thinset, thinset can ooze up between the hex tiles and partially fill the grout lines. That thinset needs to be cleaned out so the grout lines can be completely filled with grout. If it's not, you can get uneven thicknesses of grout, think of it as a veneer of grout over a blob of thinset. That can result in uneven water absorption, the grout cracking, etc. All that aside...with this being your second go-around, he should have install the sloped Kerdi Tray and thinsetted it to the subfloor. Then he should have set the Kerdi drain. Then he should have thinsetted Kerdi Membrane (an orange colored sheet material) over the Kerdi Tray, then tiled on the Kerdi Membrane. I'd be interested in how he tied the Kerdi Membrane in with the wall membrane IF he used Kerdi Membrane over the Kerdi Tray. Best. Mongo