Hi!
Here's hoping you may be able to help. My client's flat was originally a school building and not designed for residential use. A bathroom was added over 20 years ago. Now the owner wishes to change the bathtub for a shower stall. The problem is that the floor is so thin there will be great difficulty in installing a drain. We had originally hoped to use mosaic on the shower stall floor, but the contractor determined that a regular shower pan would be a better idea. Now the whole project is on hold because of the minute depth of the floor. Any ideas?
Thank you SO much!

If you has a tub you can install a shower. The trap can be recycled by installing something like a Swanstone 3260 retro shower pan, it fits in the tub foot print. You will need to extend the lateral before the trap to move it about 9" to line up with the shower drain. Swanstone Retrofit Shower Floor Left Drain - Bathroom Fixtures - Compare Prices, Reviews and Buy at NexTag - Price - Review