Steel Beams to Support Joists?
I live in an old 1920's colonial. We have a first floor great room that is 20 x 30, with a three inch sag in the center of the ceiling. We are having the upstairs rooms remodeled and when our contractor pulled up the floor, he found the joist notched, bowed, and toenailed (one corner of the house under the bathroom has joists running perpendicular to the rest of the joists). He has told us we need to have two steel beams installed, one under the main joists and another under the perpendicular joists under the bathroom. He is going to cut the joists once the beam is installed, and therefore thinks he can jack the house up within a few days. He has torn down the interior plaster walls upstairs, and so only the exterior walls are at risk. Cost is about $5500.
Does this seem reasonable? The price doesn't seem crazy, but I haven't seen much online about the use of steel beams. Can you jack the house up more quickly if you are cutting the joists and the walls are open? Should I be worried that he's going to rest these two beams on the cinderblocks within the chimney? Obviously I'm not an expert, so I appreciate any advice.