Which term is the primary horizontal structural element that spans between supports and carries loads along the building?

• A. Beam
• B. Joist
• C. Filler beam
• D. Girder

Answer: (D)

Girders are the main horizontal members that span between supports (like columns) and carry the loads from smaller framing members along the length of the building. They’re larger and deeper than typical beams and are designed to transfer those loads down to the supports, acting as the structural backbone of the frame. Beams also span between supports and carry loads, but they typically support joists or slabs and transfer loads to girders or columns, whereas girders take on the heavier, primary load path. Joists are the smaller members that run across to transfer loads to the beams and girders, and filler beams are used in specific framing situations to fill gaps. So the term that best fits the description of the primary horizontal element carrying loads along the building is girder.