I have a townhouse that I am remodeling. I am planning on removing the fiberglass shower/tub, toilet. and vanity. I would like to rip up the tile floor and install a new one. This bathroom in on the 1st floor and the townhouse is built over a concrete slab. So when I tear the tile up I will be looking at the slab. What do I need to do to prepare this for floor tile. Can I just tile over this? Also, at what point does the new tub/shower come in? Do I go ahead and tile the whole room and place the tub over it or does it come in first and tile up to the edge of the tub?