Which structural component supports vertical loads in a building?

The correct choice for the structural component that supports vertical loads in a building is the truss. Trusses are designed to distribute the weight of the roof and other vertical loads effectively across their structure. They utilize a framework of triangles to provide maximum strength with minimal materials, making them highly efficient in bearing loads.

Trusses are commonly used in roof systems to span large distances without requiring intermediate supports, making them crucial for maintaining structural integrity in both residential and commercial buildings. Their design allows them to manage various forces, including gravity, which is essential for ensuring the safety and stability of the structure over time.

Other structural components mentioned, such as sheathing, rafters, and headers, serve different purposes. Sheathing provides a surface layer that adds to the building's structural integrity and helps with wind resistance but does not primarily bear vertical loads. Rafters support the roof and do contribute to load-bearing but are not as efficient in load distribution as trusses. Headers are used to support loads over openings like doors and windows but operate on a much smaller scale compared to trusses in supporting overall building loads.