I have a sagging ceiling on a 20' open run through the middle of my living room. It is also causing the roof to sag. The piers and foundation are fine. My question is would jacking the ceiling back up to level and build an 8' wide wall under the beam be able to fix this? I don't want to spend the time or money to repace the beam and would like to break up this huge open space anyway. Any help would be appreciated.