Walk-in showers are called "douches Italiennes" in French... Is it because Italians are too lazy for lifting their legs enough to go into a tray ? No, I'm jocking: too much of French humor
When I was a builder, I always refused to install one for a customer because it was too risky about leaks, because the precautions would have lead to a huge estimate and because other brave builders had a very bad experience. Also, most of my customers wanted one upstairs on an old parquet floor with soil pipes too high.
Being retired and wanting to make one at least once in my life, I decided to have a go in our suited bedroom at the ground level.
I had to dig quite deep in all the rooms to have the soil pipes at the right level with a decent slope: lot of heavy work !
Then, I had to make a diamond shape screed with 3% slope down to a central high flow gutter. I waterproofed the floor and the walls with special membranes (Ditr/Kerdi) and sealed with polyurethan mastic where necessary.
I tiled the walls and the floor with matching tiles and mosaic. No need to mention that all the cements were waterproof !
Here we are :


