In CMU construction, which spacing is typically used for reinforcement?

• A. 12 inches
• B. 16 inches or 2 courses
• C. 18 inches
• D. 24 inches

Answer: (B)

Reinforcement spacing is chosen to align with the size of CMU units and the grout cell pattern, so bars pass through cells at predictable, workable intervals. Standard CMU units are about 8 inches tall, so placing reinforcement every two courses—16 inches—fits neatly with the unit grid. This regular interval makes it easy to grout the cells properly and ensures the reinforcement is effectively bonded into the wall, improving its shear and flexural performance. Spacing at 12 inches would cut across a whole-number course pattern awkwardly, while 18 inches or 24 inches don’t align with the typical unit height, complicating layout and grout distribution. So, 16 inches or every two courses is the typical, practical spacing.