I need to level the floor on one end of a single story frame house that is 30’x30’. The space has two beams spanning its length, each made of two 2x10s with 2x4 ledger boards attached. These beams are 48” apart and support the walls of a hallway above and at least some of the weight of the roof since the roof is not built with trusses. Both of these long beams are sagging due to failure of the metal support columns that are rusting away and due to poor footings under the failing columns. Presently the sagging beams are supported by 3 metal posts each. In addition to these beams sagging, many of the floor joists have cracked near the ledger board so that the floor sags from the outside cinder block walls to the center beams as well as along the beams. I am going to need to lift one beam about 2 inches at its lowest point and the other beam about 1 inch and then raise the joists back into position against the sub-floor.

First question - What would be the estimate of the weight of the structure I described. I had one contracter friend suggest assuming 10001b/ linear foot so about 30,000 lb of weight

Second question – I had originally planned to raise and level the two center beams and support them with new columns and then jack up the floor joists, sister new joists were needed and add joist hangers on all. This will be a huge amount of labor because I will need to custom cut sections of 2x6 filler board to nail between every set of joists above the ledger to have something to attach the joist hangers to. There would be 4 to make between every joist because I have this problem on the outside joists as well as on the 48” joists between the two main beams under the hallway that is above However, someone suggested using sections of 10” channel iron under the beams so that when I raise the channel iron it will catch and raise the sagging joists as it also raises the beams to level. The thought is to place a 4’ section of channel iron above each new support post so that at least that much of the joist raising would be taken care of as well as to distribute the load along the surface of the beam. Does this sound feasible?