The house was moved to its current location in 1948. I am guessing
the add on was done in the 60s.

the plumber did run a camera under the house and he said it was clear,
but when he ran the camera the pipe was full of water so I am not sure
how much he could tell.

The plumbing problem was caused by some foundation work done on the
add-on part of the house. A pier was put to close to the pipe causing
it to calapse. The plumber fixed that part. It has a been a
nightmare because the foundation company did not know they hit the
sewer line and the sewer did not back up until a month after the
foundation work had been done. All the plumbers assumed that the
sewer line went from the cleanout directly to the street. The 3rd
plumber dug up the line and noticed it wrapped around the back of the
house under the add-on section and attached to the city sewer on a
side street since I live on a corner lot. This is when we found a
pier going through the sewer line. This is my only bathroom and the
kitchen and the washing machine attach to the pipe on the other side
of the add-on so they are not backing up.

I guess the first thing I need to do is have the plumber run the
camera again.