SLBB stands for “short legs back-to-back.” Alternatively, LLBB stands for “long legs back-to-back.”

SLV stands for “short leg vertical.” Alternatively, LLV stands for “long leg vertical.”

From Tide and Krogstad (1993), “Factors such as deformation of lower courses of masonry during construction and the rigidity of masonry walls after the mortar begins to set cause shelf angles to be loaded by a combination of uniform and concentrated loads acting near the back edge of the masonry. Restraint provided by friction and the masonry ties reduces torsional forces and deflection and provides lateral support for the shelf angles.” A design procedure that accounts for these factors can be found in Tide and Krogstad (1993).

Tide, R.H.R and N.V. Krogstad, 1993, “Economical Design of Shelf Angles,” Proceedings of the Symposium on Masonry: Design and Construction, Problems and Repair, STP 1180, American Society for Testing and Materials, Philadelphia, PA.