What is the secondary purpose of a roof in a masonry building?

The secondary purpose of a roof in a masonry building is to stabilize the walls. In masonry construction, the roof serves not only as a protective barrier against the elements but also plays a critical role in maintaining the structural integrity of the walls. The weight of the roof and its connection to the wall systems help distribute loads, counteract lateral forces, and prevent the walls from leaning or collapsing under various stresses, such as those caused by wind or seismic activity.

By designing the roof to effectively interact with the walls, architects and structural engineers ensure that the building remains stable and safe. This relationship is particularly important in masonry structures, which can be susceptible to cracking or failure if not properly supported.

While insulation, aesthetic value, and rainwater collection are relevant features of a roof, they do not address the primary structural role the roof plays in stabilizing the masonry walls. Insulation is primarily concerned with energy efficiency, aesthetic value pertains to appearance, and rainwater collection is about managing runoff, but none of these functions are foundational to the building's structural stability in the way that the roof’s connection does.