Mortar is not the same as concrete. It's designed to bond masonry units together, fill gaps, and create a weather-tight seal.
Mortar Types (ASTM C270)
- Type M (2,500 psi): Below-grade, foundations, retaining walls
- Type S (1,800 psi): Structural, exterior walls, severe weather
- Type N (750 psi): General purpose, above-grade (most common)
- Type O (350 psi): Interior, non-load-bearing
Mix Ratio (Type N)
1 part cement : 1 part lime : 5–6 parts sand. Add water until workable consistency.