There"s many stories in the field regarding all kind of bad work done. Recently we had a service where the kitchen sink drain in basement unit was backing up. Two other companies was there to do the work. One tried to use the air gun and blown up the strainers, and p traps , and the other one couldn't do it at all. What we did!? First we rodded and because of the length of the cable( 60') we couldn't open. Next day we tried to jet and we couldn't pas the first joint. With owner permit we cut the wall and with camera we saw kind of Picasso art. After 2" copper pipe 4" cast iron pipe and again 2" copper pipe and again 4" copper pipe. After jet and rodding we pulled out plastic bags. The whole work: 8 hrs. Because of very skilled plumbers, whit license of course.