Masonry
Units and coursing
Concrete masonry units are 8x8x16 nominal, but the actual face is 7-5/8 by 15-5/8 inches because a 3/8-inch mortar joint completes the module. Modular brick is 3-5/8 x 2-1/4 x 7-5/8, and with joints the module closes at 8 inches in both face dimensions. Coursing must be laid out from a story pole so bond beams, lintels, and shelf angles land on module.
Mortar and grout
Mortar types are ranked by strength: M for the highest, S for structural and at-grade or sewer work, N for general above-grade weathering, and O for nonloadbearing interior use. Joints are tooled concave to densify the surface. Grout in reinforced cells is placed in lifts, consolidated, and limited in pour height unless self-consolidating grout is specified. Reinforcing, bond beams, and vertical wall reinforcement follow the structural drawings.
Water management
Through-wall flashing goes at the wall base, over lintels, at sills, and at roof intersections, with weep holes above it. Cavity drainage and air space matter as much as the masonry itself, and efflorescence usually signals moisture migration.
Traps
Confusing nominal and actual dimensions or joint thickness; specifying Type N where Type S is needed; omitting control joints and reinforcement; and forgetting that walls need temporary bracing until the diaphragm is complete.
Rule of thumb: about 1.125 standard 8x8x16 CMU per square foot of wall face, allowing for joints and waste.