Concrete Block Fill Estimator
Estimate grout volume and 80-lb concrete bag count to fill CMU block cores — full fill, alternating cores, or bond-beam only.
Limitations: Bond-beam-only factor is a rough average — actual varies with wall height and reinforcement pattern. Lightweight CMU cores run about 5% smaller than this estimate. Does not include waste.
What to do next: Fine-aggregate grout (ASTM C476) is recommended for core-filling; ready-mix 80-lb bags can work for small jobs. Low-lift grouting limits lifts to 5 ft per pour. High-lift grouting needs cleanouts.
Planning estimate only. Structural masonry core-fill quantities must follow the engineer-of-record and reinforcement schedule.