shower addition

[Danny]

I am adding a shower to an old laundry location. Drain exists out wall and floor is concrete slab.  Does the new shower have to have an "s" bend under it.  How high would the shower have to be off the floor to accommodate this if it is needed?

[PlumbingHelp]

Every fixture needs a trap under(or in) it to block sewer gasses from entering the home. "S" traps are not permitted, what you want is a P-trap. I take it breaking the floor and installing it on grade is not something your looking to do? Most people who build up to install a new bathroom find they don't like afterwards. If you plan to put where the washers stand pipe is there is a good chance an underground pipe is very handy that you could connect to.
As for the height issue it depends on whether you use a 2" or 1-1/5" trap and how far the pipe needs to run at 1/4" per foot. Most are built on top of 6", 8" or 10" joists.