A friend bought an older home that has roof trusses and not just rafters. The kitchen wall down the middle of the house we are assuming is load bearing. The bottom plate of the wall was significant water damage and has pretty much disinigrated. Also to add to insult the floor has sagged causing the ceiling to follow suit. We were wanting to place a 4X4 across the ceiling for a temporary beam, catching all the trusses in that room and just relieve some pressure off that wall by jacking it up a little and cutting the bottom 2' off the wall and replacing bottom plate and then sistering the cut off studs and then filling in the gap down to the sill plate. After replacing the plate and setting the wall back down on the floor joists then we need to jack up the floor and shim the house beam in the crawl space. I guess the main question is, is there a problem with jacking that wall just enough to cut it out or should we go about this a different way?