I plan on building a tile shower on an concrete slab with drain already in place (there was an existing show in place) which sticks up about an inch from the slab (possibly there is a piece I can remove to bring the drain back down below slab level). The walls will be 2x4 stud and I'm planning on a wood curb consisting of 3 2x4.

I'm looking for basic steps on how to do this. I've found a number of how-to's online but none seem to refer specifically to building on the slab. I can understand that on a wood joist floor perhaps in the upper floor of a house, waterproofing via membrane is key but I'm not clear on the importance of that for an on slab tub.

So I have these questions

- is a concrete curb better than wood in this case?
- what type of drain set up would I use?
- do I need to pour a thin layer of concrete to slope the floor towards the drain?
- do I need duroc or other concrete all the way up or just one course (i.e. - 32" or whatever widths they come in)?
- would I use the waterproof wall board for the rest of the shower (i.e. - green drywall)?