Steel deck diaphragms distribute lateral load to the vertical components of the structure lateral load resisting systems. Important components in this transfer are the diaphragm chords and collectors. This session will explore the role the chords and collectors play in the diaphragm design and how the design can vary depending on the location of the lateral resisting elements. Examples will include diaphragms in steel framed buildings and also diaphragms in bearing wall buildings such as warehouse (including four-or-three-sided boxes, interior collectors, and irregular plans).