I'm planning on building a custom sized shower stall. I know this requires a bed of mortar to lay under my rubberized sheet. What do I use as a "bed of mortar"? will basic mortar work, or do I need anything special. Also, do I need to put reinforcing steel mesh or anything in it to hold up?
Any other tips you can share about custom tile shower stalls would be helpful. This will be my first one.