What do I do with a sewer pipe (toilet rough-in) full of cement?
Since the ultimate solution may be to open floor and cut out the affected drains, lets hope it was only a  poorly sealed cap..  Its worth a few experiments:


Screw in a wedge anchor in center (of cement in drain) and use several pry bars or jacks to lift slug out

Drill a few inches down with a 2" coring bit (rented with a SDS max rotary hammer at local orange big box).  Repeat across the face of drain, being careful not to drill through drain.  Try chisel and point bits to see how deep it extends.  Shop vac pieces as you go, in case you breakthrough (think positively).





Call emergency hotline on the extended home warranty policy (its in with the mortgage papers)