This detail illustrates a a shelf angle mechanically fastened to the concrete masonry backup with anchor bolts at regular intervals. There is no provision for thermal break other than the shims behind the shelf angle. The primary function of the shims is to bring the angle out the required distance to adequately support the brick veneer. There is a horizontal expansion joint below the shelf angle to allow for vertical expansion of the brick veneer. A course of lipped brick, usually prefabricated, resides above the shelf angle to tighten up the the joint width visible below the shelf angle. The downturn in the lipped brick requires the flashing to make a few bends as it traverses the wall. The flashing protects the shelf angle, and weep vents allow moisture to exit the wall. A drip edge is recommended in this application, to further protect the steel angle and to ensure water does not travel back into the wall beneath the flashing.