"I'm not very worried about the traction under foot, as my tiles are textured and hence has excellent traction. The look of the large format tile is what I was going after at the very beginning." Me too - ours have texture and are recommended for many applications, but do make sure you test a couple of yours out before you live with them - wet one down outside or in the garage and stand on it. Maybe even add soap. Move around. Bend over and pretend to pick up the soap. I was OK with them but after doing this a couple of times, my husband felt he definitely could slip (especially as we age) on a 12x24 tile. And he's pretty agile. The tile setter and the GC both recommend more grout lines for safety. The shower floor tiles will be cut a little smaller than the average foot size and the rest of the room will remain large format. I LOVE the large format but made the concession.

To do what he's proposing, you cannot have a "bowl" mud slope. Take a rectangle and draw two lines from corner to corner. The resultant triangles will have to be completely flat planes that slope towards the center point where the two lines intersect (your drain). Your shower floor will have that X in it in grout from the cut tiles. This is MUCH MUCH harder to do than a bowl preslope, as it has to be sloped correctly and perfectly flat, and the intersecting X lines can be difficult to achieve uniformly for a novice. It CAN look great when done by a pro, but it can also be a slippery uneven nightmare if done by a hack who can't get it level and with tile that isn't rough enough to give your feet grip on a wet surface.

My goodness. This thread has gone off the deep end. First of all, simultaneous water sources are not allowed in CA. One at a time only. And even if I could, I wouldn't. I conserve water at every opportunity. I know that until very recently Texas was in a severe drought so I hope you only recently started wasting water with "SUPER long" showers and multiple water sources. These days this kind of behavior is frowned upon in much of the country even when there isn't a drought condition. None of the surfaces in the renderings are true. I said the colors are "generic" meaning don't pay attention to any of that. Maybe that wasn't clear but there is no wood in the bathroom so it's not a concern. As for completely undoable, you guys have lost your minds in terms of the drainage needed. There is one showerhead with a full four foot long linear drain under it. And for the next four feet away from the drain there is a downward slope aimed at that drain at 1/2" per foot for a total of 2" rise. The entrance to the shower is another good foot or two away from where the slope even begins. There is no way water from a low flow showerhead is going to travel four feet uphill, then traverse another foot or two of flatland and then follow that by making a sharp right turn to exit the shower. Not. Going. To. Happen. At least not on the planet Earth. I don't need two drains. I was not questioning if the shower design was OK. I was questioning whether or not a certain type of linear drain could be used in this design because the manufacturer's verbiage was unclear. I have spoken to Quickdrain and they assured me that the TileIn drain and WallDrain will be fine with this design. And these are their least capable linear drains. I suppose there is a question about whether or not code requires the entire floor surface to be sloped but the people working on my house have done curbless showers (one guy was brought in specifically to do the shower floor and drain because he is a curbless specialist) and they don't see an issue. I will still ask my inspector when I see him to be sure. I might actually prefer the entire surface to slope back towards the wall and away from the door just so that the floor of the shower is seamless. I hadn't considered that option but if I do it, it would be for aesthetic reasons not because what I have will not contain the water.

laynemcd24, can you share what size and type of tile you are using on the shower floor? We are planning to do large porcelain tile on the shower floor with a linear drain, just like you. I know it's always recommended to use smaller tiles on the shower floor for more grout lines and traction (and for sloping toward the drain), and I know we'll need to find a tile with an appropriate DCOF so that it's not slippery.