What is the maximum spacing of the rebar in the stem wall?

What is the maximum spacing of the rebar in the stem wall?

• A. 12 inches
• B. 18 inches
• C. 24 inches
• D. 36 inches

Answer: (B)

Reinforcement spacing in stem walls is limited to keep the steel distributed enough to control cracks and carry the loads the wall experiences. The maximum is 18 inches on center, meaning the centers of adjacent vertical bars can’t be more than 18 inches apart. This closer placement helps ensure the wall can resist bending, shear, and earth pressure, and it keeps any cracks from becoming wide or uncontrolled as the concrete shrinks or as loads change. If bars were farther apart, portions of the wall might go under-reinforced, leading to bigger cracks and reduced structural performance. The other options would place bars too far apart or unnecessarily tight for typical stem-wall construction.

Reinforcement spacing in stem walls is limited to keep the steel distributed enough to control cracks and carry the loads the wall experiences. The maximum is 18 inches on center, meaning the centers of adjacent vertical bars can’t be more than 18 inches apart. This closer placement helps ensure the wall can resist bending, shear, and earth pressure, and it keeps any cracks from becoming wide or uncontrolled as the concrete shrinks or as loads change. If bars were farther apart, portions of the wall might go under-reinforced, leading to bigger cracks and reduced structural performance. The other options would place bars too far apart or unnecessarily tight for typical stem-wall construction.