My kitchen sink on the ground floor drains into a 2" steel pipe that goes out the roof and joins a cast iron drain pipe at the basement floor. Approximately 34 years ago, I had a rooter guy cleaning out my kitchen drain. He used a snake and could not get it past the elbow of the cast iron pipe at the basement floor level. The snake broke off at the elbow and was never retrieved. The rooter guy put a balloon on the end of a garden hose and lowered it down the vent pipe on the roof until it was below the level of the kitchen sink drain. Then I turned on the water and the pressure blasted the clog free, but the snake head was still at the basement floor level elbow. Every year since then, in the Autumn, I would lower a balloon down the pipe and blast the line clear before Winter came. This year I was busy with other house emergencies and never got around to it. The drain clogged. I hired a plumber (not a rooter guy) to go up and blast it out for me. He insisted on taking a snake up to the roof. I let him go up to find out for himself. He sought the use of my garden hose and balloon to blast the clog out as I originally wanted him to. But, it did not clear the drain. Now, the sink was completely clogged and not just slow. We went to the basement and I showed him the 2" pipe that came from the kitchen sink down along the basement wall and where the cast iron pipe disappears into the basement floor. He said the only solution was to jackhammer the cement floor and replace the cast iron pipe that goes along underneath the basement floor. I thanked him for his services and told him I would have to leave it as it was. He charged me $95 and the sink is still clogged. Now the floor under which the cast iron pipe goes towards the main line is in a fully carpeted, fully furnished den. I propose to saw through the steel pipe far enough above the union with the cast iron pipe that I will be able to fit a no-hub fitting around the pipe at the cut when I have the pipe cleaned out. I would then make another cut 18" higher to remove a section of pipe to allow access to the joint where I believe the snake head is. After the retrieval I would be able to replace the removed section of pipe and fasten it in place with 2 no-hub connectors. What problems do you see with my proposed approach?