Joe wrote:
I have a house that has a half bath on the lower level I want to add a
shower. The only new problem I am faced with is this is a concrete floor, no
crawl space under this one. The sink drain is the closest drain and it goes
straight into the floor. This house is forty years old and is all cast
drains and vent with copper drain lines connecting to the cast ones, no PVC
here. I plan on just busting up the concrete to see what is there. Any one
ever done a job like this? Any input on what I might find would be a help, I
would like to know how deep the sink drain goes down before turning so I can
figure out if the shower will be flush with the floor or will I need to
raise it up?

What you'll find will depend largely on how the fixtures are laid out
in relationship to each other and the main and any laterals. If the
sink is isolated and on a separate line, it quite likely isn't large
enough to handle a shower, too. If, otoh, it feeds into the lateral
servicing the toilet, that is probably adequate. Again, depending on
the geometry, it might be relatively easy to insert a tee for the
shower and go from that point to the main or lateral of adequate size.
The possibilities are almost innumerable. How deep also will depend on
the depth of the external sewer, the length of the run, how deep is the
frost line there, etc., etc., etc. You have a treasure hunt in front
you, undoubtedly... Although if you map out the overall plumbing
layout, you may be able to reasonably deduce the direction and location
of lines, particularly if you do know where the main line leaves the
house. With that, you could also probably make reasonable guesstimates
of line sizes and if you were to know the exit line depth perchance, of
the depth of lines there as well.