[Hondaracer]

Personally I’d be very hesitant to just tile a floor and rely on the waterproofing/drainage to prevent a leak, especially if it’s an upstairs bathroom

My contractor has a guy who makes custom fiberglass shower bases to whatever size/drain location you need, I can get a contact for you if you want.

I don’t have a picture but I’ll take one when I get home of ours, it’s a custom base that was then tiled over, looks great and is virtually leak proof the way the drain etc. is configured