In the structural hierarchy describing how building loads reach the earth, which sequence is correct?

• A. Sheathing -> Rafters/Joists/Beams -> Columns -> Foundations -> Earth
• B. Rafters/Joists/Beams -> Sheathing -> Columns -> Foundations -> Earth
• C. Floors -> Walls -> Columns -> Foundations -> Earth
• D. Earth -> Foundations -> Columns -> Joists -> Sheathing

Answer: (A)

Loads begin at the top and flow downward through the building’s structural system. The roof’s weight is first carried by the roof deck, or sheathing, which collects the load from the roofing material and distributes it to the roof framing (rafters, joists, and beams). Those framing members then transfer the load to the vertical supports—columns or load-bearing walls. From there, the force moves into the foundations, which spread it into the soil (earth). This downward path from sheathing to rafters/joists/beams to columns to foundations to earth reflects how a typical building actually carries load: the surface layers hand off weight to the framing, which hands it off to the foundation and finally into the ground. The other sequences don’t follow the actual flow of loads, either placing the framing before the sheathing or reversing the direction toward the earth.