Sewer Line Query
I own a c1925 house and I'm experiencing back up coming into the basement from the floor drain. It is from showers and washing machine use. Four years ago I had a repair done that included a slip liner in the main line to the street plus a dig and replacement of about 6 feet or more of broken up pipe near the house. It has backed up a couple of times and the plumber put a camera down the line and he tells me there is a "hump" about 15 feet outside the house. The line is about 40 feet house to street and 7 feet down, 8 feet at the street.
I'm getting estimates and they are high: one is $8,000 another $4,600 for replacing the line from the house to street, 40 feet. There is a walk way they say needs to be cut away and replaced and a brick-lined flower bed that will require some work to put back right. The line is deep, 7 to 8 feet and therefore has to be wide. It will tear up the yard and while they will put it back, it will be a mess to make right again and the walk way will never look the same.
I'm wondering why a hump would develop. Roots? There are very large threes about 30 feet away from the line.
I'm also wondering if there is a less expensive and less destructive way to go about the repair.
I'm going to begin by getting a second opinion. The guy making the lower bid graciously offered to scope the line for free before doing any repair. I think I'll wait to see what he says.
I welcome your theories and suggestions.