Structural Steel Erection
CSI Division 05, Metals
The sequenced process of lifting, positioning, and connecting a building's fabricated steel members in the field, following an engineered erection plan that keeps the partially assembled frame stable and braced at every stage, distinct from the fabrication of the steel itself.
Why it matters
OSHA's steel erection standard sets specific requirements, such as a minimum of two bolts per connection before a member is considered self-supporting, because an erection sequence that gets ahead of itself leaves an unstable frame that can collapse under wind or its own weight before enough connections are made.
On a real project
An erection crew sets and connects each level's steel following the engineer's erection plan, keeping temporary guy cables and braces on each piece until enough permanent bolted or welded connections are complete to make that section self-supporting.
Who this matters most to
An Ironworker makes the field connections and bolts up each piece. A Structural Engineer or a specialty erection engineer designs the sequence and temporary bracing the crew follows.
Where this goes wrong
An erection crew, pushing to keep the crane moving, fully bolts up several bays ahead of the engineer's approved sequence without waiting for the survey check the sequence calls for at that stage. By the time the surveyor catches the cumulative drift, three already-completed bays are out of tolerance, and the crew has to loosen and reset connections across all three rather than just the one where the drift started.