Which building component supports the weight of the roof?

The correct answer is that exterior walls support the weight of the roof. In a typical building structure, the exterior walls serve as vertical support elements that carry the load from the roof and distribute it down to the foundation. They are designed to withstand the weight of the roof system, which includes the roofing material, any insulation, and the framing that makes up the roofing structure.

While roof framing systems, such as rafters, transfer the load of the roof to the walls, it is ultimately the exterior walls that bear the majority of that load. They provide the necessary structural integrity to ensure the roof remains stable and secure over the life of the building. Other components, such as ceiling joists and floor beams, play roles in their respective areas (supporting ceilings and floors), but they do not directly support the roof's weight in the same way that exterior walls do.