What is the minimum required size of a steel angle used as a lintel supporting one story of masonry veneer above?

The minimum required size of a steel angle used as a lintel to support one story of masonry veneer is determined by its ability to handle the loads imposed by the structure above. The correct option provides a size that offers sufficient strength and stiffness to resist bending and shear forces acting on the lintel.

A steel angle of 5x3-1/2x5/16 is typically capable of spanning the common widths of openings in masonry veneer and supports the weight of the veneer itself without excessive deflection. Additionally, the dimensions reflect a balance between the weight of the lintel itself, the load it carries, and the material properties of steel. The thickness of 5/16 inches provides adequate strength to support typical masonry veneer loads, ensuring safety and compliance with building codes.

In contrast, the other options may not provide the necessary properties for standard masonry veneer applications, either being too small in cross-section or lacking the strength required based on the structural design principles. Using a lintel that is not adequately sized can lead to failures such as cracking in the masonry or structural issues. Therefore, the selected size reflects the balance of safety, material efficiency, and compliance with standard building practices.