Sewer Pipe Repair Question

[Ernest Ho]

Earlier this year, I bought property that was originally built in 1927.   I've recently had some drama in dealing with sewer pipe repair, and I would appreciate your advise.

Soon after my tenant moved in, she encountered problems with plumbing.  Plumbing inside the house is all new, so the problem is the sewer pipe from house to street.  After the initial camera inspection, the plumber located the breakage due to roots.  It's about half way from house to street.  After fixing it, stoppage occurred again.  They did another inspection, and found paper at the end of the pipe close to the street.  They said it's old paper from prior owner.  After they cleared it, stoppage happened again.  This time, they did another camera inspection and found another breakage close to the street.

Should the plumber be liable for not finding out whats going on all the way from house to street?  It took them 3 or 4 camera jobs to find out what's going on. They should have done another inspection when they fixed the pipe the first time, but they did not.

Or is this legit, and I will have to pay for repairing the newly found breakage?

Thanks.