In this house the beam across the second floor over the garage was not sized right by the builder. It had deflected (bent) down over time, and the homeowner was unhappy with the large dip in his floor above. He hired us to come out and fix the beam. Our first step was to expose the beam, and jack it into place. Here we are exposing the beam, and this illustrates the problem:
chalk line showing bowing beam
Here we have put LVL Beams in place to stiffen the beam: