TE certified will sawcut, excavate, replace the original cast-iron Underneath the slab, put back dirt, and pour concrete to a rough grade level. Also will dig outside up to the backwater valve. Installation: We removed the concrete from the toilet to the outside wall in line with the backwater valve. We excavated down to the old cast iron drain line, exposing it all the way to the back water valve. Replaced all cast iron with new 4” pvc pipe. We had to tie back into 3 separate branches in the bathroom/laundry room area. Thoroughly tested ensuring no leaks and proper flow. Back filled and cleaned up site. Then we poured back concrete.