How thick must footings for masonry chimneys be made of concrete or solid masonry?

The correct choice indicates that footings for masonry chimneys must be a minimum of 1 foot thick. This specification is important because proper footing thickness ensures that the load from the chimney is adequately supported by the foundation, providing stability and preventing settling or shifting over time.

Footings need to distribute the weight of the chimney evenly across the soil beneath to avoid any structural issues. This thickness is typically set by building codes and standards to maintain the safety and integrity of the structure, especially since chimneys can be quite heavy due to the materials used and the design. A 1-foot thickness strikes a balance between sufficient support and practicality in construction, thus it is deemed the minimum requirement.

Other options suggest various thicknesses that are either below or above what is mandated for proper structural support. It is crucial to adhere to local building codes which specify the necessary dimensions for safety and performance.