Depends on the measurements. It need to be 48” deep from the entry, with a trench drain at the wall, if you’re just going to jackhammer the slab to lower a section. If you can’t get that depth, then you need to go a wetroom setup, with the whole room sloped and waterproofed to the drain, as a big giant shower.

Thanks! @HO-UZZ812, the shower is 53”x 48” and we can make that 49” if needed. From the entry it will be 53” but we have a shower head on two adjacent walls.

2 shower heads in a shower that size I would plan on the entire room or at least half being considered a wetroom and a crap ton of chopping of the floor. Just my 2 cents.

48” is just the minimum depth for curbless when not wanting to do a wetroom build. That is at the steeper allowable 1/2” per 1’ slope, rather than the minimum 1/4” per 1’ slope. If you want a less steep slope, or a center drain, you’re back into wetroom build area. Even a “standard” curbless should be waterproofed out several inches from the entry, with a capillary break between it and the rest of the bath.

Mine is not an uninterrupted tile floor like yours will be. I have a wheelchair accessible solid surface pan. We waterproofed and sloped our entire bathroom floor and put a drain in the floor in case of shower overflow, and I am so glad we did. It is easier than you would think to have a drain clog. Long hair and a bout of hair loss clogged mine in one shower once. I would suggest you do everything possible to prevent a problem. Slope as much as you are able.

What Joe Corlett said :)

This turns into a messy code interpretation issue and I would want the building inspector to see the drain design and plan before doing it. I have done curbless showers but don’t take it for granted that the next one will be checked by the same inspector.

You have to make sure a second floor drain either is or is not going to be required in the room before going further with design.

1/2” per foot slope is just too steep for inside a shower and I wouldn‘t go there if that is ever a suggestion.