Evaluation and modification of joists is often required due to the addition of roof
top units, underhung conveyors, loading increases, field deviations, or other
changes not contemplated in the original specification for the joists or Joist
Girders. The purpose of this digest is to present procedures, and to suggest
details for the modification or strengthening of open web steel joists and Joist
Girders. Both open web steel joists and Joist Girders will be referred to as joists
in this digest.