So back to sewers, I am getting some estimates for repair jobs as I suspect this will be plugging again in short order. Today I got an estimate of $3500 which would cover replacing the tap and connection to the sewer (maybe that is same as tap?), adding a 6" cleanout a few feet back from the tap, which can be reamed towards the house but also towards the main line. He would do this, including permits, for $3500. He will throw in sliplining the entire line (about 70 to 80 feet), which would eliminate my root problem along the line, for only $200 more, and including removing the belly (sag). He measured the sewer in the neighbor's yard. The bottom of the main line (a 12" line according to the city) was 12 feet below grade. Since I am downstream he would have to dig a hole about 12.5 feet deep. Soil in my area that they have encountered is neither clay nor sand, but a mix, which he says is good for easy digging yet stability. Cold temps also add stability. Happens, sewer is centered directly on the fence line (or I should say vice versa).
The cleanout would be handy for the motorhome, though I would have to dump into a transfer tank then dump the tank into the cleanout.
Wife doesn't want to spend the money (worse yet doesn't want any of the trees removed, which depends on the tap location). I don't want to spend the money (especially after the last 6+ months of Wall Street). But to me it is a no brainer. Broken sewer line=recurring problems. Fix it and get on with life. Will have to wait until it gets bad again, then wife may run with it.