Shelf angle

In masonry veneer building construction, a shelf angle is a steel angle which supports the weight of brick or stone veneer and transfers that weight onto the main structure of the building.

Background

Traditional masonry buildings had thick load bearing walls that supported the weight of the building. Openings in these load bearing walls for elements such as doors and windows were typically small and spanned by lintels or arches.

Modern buildings

The invention of skeleton frame buildings made it possible to have wide openings such as ribbon windows extending across most or all of the building facade. In most such buildings, brick, stone, or other masonry cladding is often a single wythe of material also called a veneer. The only way to support the weight of this veneer across a wide opening is by providing a shelf angle on which the masonry bears. The shelf angle, in turn, is attached to major elements of the building structure such as floor beams or structural columns. Shelf angles are also called relief angles. In the United States, common sizes for steel shelf angles include L 3" x 3" x 1/4" and L 4" x 4" x 1/4".

In addition to supporting the weight of masonry, shelf angles create logical locations for movement joints.