In August of 2002 I posted my sewer back-up problem. The threads are
at these links:
This a follow-up. In December of 2002 a plumbing company came to my
condominium, put a camera down the pipe several times, drilled holes
in my living room floor and in the laundry room floor downstairs (the
laundry room is NOT directly under my unit--it is under my next door
neighbor's unit), and replaced pipes running under my living room and
pipes running under the laundry room. Since then the problem has not
occurred, and it's been more than one year. The repair was about
$12,000---the condominium association paid for it. Expensive.
I hope this helps someone.