It is amazing what a contractor will cover up to avoid a minor cost that may cost the owner several hundred later to fix. My previous home had a sewer line that stopped up occassionally for several years, usually at the worst time. Finally I had a plumber run a camera down it and find the culprit. The power company had hit it with a ditchwitch and knocked a small hole in it which they just covered with a piece of plastic oil can. This kept the dirt out but allowed roots to grow into the pipe which would eventually stop it from flowing. A quick rotorooter and it was back going again but was a pain to keep doing about once a year. They knew they had damaged it, and just covered their mistake. Same thing happened with my UG power cables to the same house. It was a vacant lot on one side and while I was living in Canada, they built a house and the power company came in with their ditchwitch and trenched for his cable to connect up at the same junction box. Being too lazy to hand dig around the J box, they just started trenching too far back and knocked all the insulation off one of my 2/0 main feed cables which allowed the current to drain into the ground. I had 110V power but when I turned on the range, all the lights would dim. I had a little trouble convincing the builder of the house next door to replace over 200 feet of 2/0 cable but when I produced the chewed off portion, he agreed to fix it for free. I still had to pay the power company $100 for renting a temp. cable for a month before the builder could get it fixed. This was a $2000 repair that I came close to having to eat.