Masonry Grout: Core Fill & Structural Grouting (2026)
Masonry grout is a high-slump flowable mixture of cement, sand, and water used to fill concrete block cores and bond them to reinforcing steel. It provides structural continuity in reinforced masonry walls. Available in fine and coarse grades depending on core size and aggregate requirements.
Key Features
- High-slump flowable mix; Bonds rebar to block cores; Fine and coarse grades; 2000+ PSI compressive strength; Pre-blended bag option
Specifications
Applications
- CMU core fill; Reinforced masonry walls; Bond beam filling; Lintel grouting; Structural column fill
Installation Overview
Mix to pourable consistency at 8-11 inch slump. Pour into block cores in lifts of no more than 4 feet. Consolidate each lift by puddling or vibration. Allow to set before adding next lift.
Pros & Cons
Pros
- ✓ Creates monolithic reinforced wall; Flowable for easy placement; Strong structural bond; Pre-blended options available; Code-compliant
Cons
- ✗ Requires proper consolidation; Can shrink with too much water; Heavy bags; Must be placed in lifts; Short working window
Top Brands
Code Requirements
Must meet ASTM C476. Minimum 2000 PSI. Grouting procedures per TMS 402/602. Consolidation required per IRC R606.
Buying Tips
Use fine grout for cores under 2 inches wide and coarse grout for larger cores. Never add excess water to improve flow - it weakens strength. For large projects consider ready-mix delivery.