Cost calculation for tile installation 260x90

If the desire is "seamless" - look for an alternative technology to the cut giant tile. That will be expensive rubbish.

My tiler charges 700€ for this size 240x120cm (including tile, including installation) For the size 320x160cm he gets 1000€ (also including tile and installation) Since my tiler has a waterjet cutting machine, the tile is adapted absolutely precisely to the conditions. That means the installation location is measured exactly with a laser and the tile is then cut exactly to this size (of course with some clearance on both sides). The holes are also cut to the millimeter exactly. For him, it doesn't matter how many holes or how much cutting is required, always the same price. And I don't find this extremely expensive.

I find the prices fair... but how do you get 3.2x1.6 into the house?

When I think about how often you bump into things transporting a slatted frame (2x1.8)....

And the slatted frame is 100 kg lighter ;)

The tiles are not as heavy as you think, they are only 6mm thick. But yes, handling the tiles is not easy, especially if you want the floor, e.g. the shower, to be made from one piece (tile), you don’t have any space to stand and lay them. You have to be creative then. ;)

The OP was looking for a solution for "seamless" and through this incision for shampoo etc., but the exact opposite occurs. Therefore, in my opinion, this makes little sense for him, but I find the descriptions of the general process interesting.