The Steel-to-Joist Interface
Open-web steel joists bear on the top flanges of structural steel beams. The joist manufacturer produces shop drawings that show seat bearing depth, seat height, and bearing length. If the structural beam changes in size between the structural drawings and the final approved framing, the seat height changes and the joist may not bear correctly. The detailer must coordinate beam top-of-steel elevations with the joist engineer's seat height calculations — this requires that the joist drawings be in hand during structural detailing, not after.
The Deck-to-Steel Interface
Metal deck attaches to structural beams and joists by puddle welds or mechanical fasteners. Deck can span continuously over joists or terminate at structural beams. Where MEP penetrations are required through the deck, they need to be coordinated with the framing — large openings require supplemental framing angles or header beams that must appear on the structural drawings. Deck penetrations that are not shown on structural drawings during detailing become field additions that delay the decking crew.
MEP Coordination Requirements for the Structural Model
For effective MEP coordination, the structural steel model should be shared with the MEP coordinator (typically the GC's BIM coordinator) in IFC format before MEP detailing is complete. This allows MEP subs to route their systems around known steel obstacles rather than designing in a void and discovering conflicts at the coordination meeting. The structural detailer should attend coordination meetings and be able to evaluate whether proposed MEP routing requires structural modifications — and flag those to the EOR immediately.