Structural Engineering · Engineering Glossary
A Concrete Masonry Unit (CMU) is a precast hollow or solid concrete block used in walls and partitions throughout commercial and industrial construction. CMU walls can be load-bearing or non-load-bearing, and can be reinforced with rebar grouted into the cells to resist lateral and axial loads.
Reinforced CMU is commonly used for tilt-up building infill panels, exterior walls of retail and warehouse buildings, fire-rated shaft enclosures, and retaining walls. The structural design of CMU follows ACI 530, the Building Code Requirements and Specification for Masonry Structures. Key design decisions include the size of the CMU cell, the spacing and size of vertical rebar, horizontal joint reinforcement, and the grout mix. Cutting openings in existing CMU walls requires engineering to verify the existing wall capacity, design the lintel, and detail the jamb reinforcement — work Apex Grid regularly performs on tenant improvement and renovation projects.
Apex Grid Engineering maintains this glossary as a resource for architects, contractors, developers, and property owners who encounter unfamiliar engineering terminology on their projects.
View All Engineering TermsApex Grid's licensed PEs provide structural engineering services across multiple jurisdictions — with fast quote turnaround and permit-ready documents.
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