Watching these load bearing I-Beams installed make it look easy considering their very significant role in the structural integrity of the building. It usually requires a minimum of two people to accomplish the task safely. Even a short six foot long double 2×12 beam can be very heavy. The beams on the corner support the building walls. The beams in the middle will support the elevator shaft and the horizontal beams, there are 2 of them along the perimeter of the building, will carry the load of the second floor and the third floor.
Structural engineers calculate the kind and quantity of I-beams required depending on the load it will “support”.