Mortar is the glue that holds brickwork together. Using the wrong ratio either wastes expensive cement or produces weak joints that crack under load. Here are the standard ratios for different applications.
Standard Mortar Mix Ratios (Cement : Sand)
| Application | Ratio | Strength Class |
|---|---|---|
| Load-bearing walls (ground floor) | 1:4 | M7.5 |
| Load-bearing walls (upper floors) | 1:5 | M5 |
| Partition / non-load-bearing walls | 1:6 | M3 |
| Foundation / plinth level | 1:3 or 1:4 | M10 / M7.5 |
| External plastering | 1:4 | M7.5 |
| Internal plastering | 1:5 or 1:6 | M5 / M3 |
How to Mix Mortar on Site
- Measure cement and sand by volume using the same container (typically a tin or bucket)
- Dry-mix cement and sand until the colour is uniform — no streaks
- Add water gradually. Target consistency: mortar should hold its shape when squeezed but not be crumbly
- Use mixed mortar within 30 minutes. Do not re-temper (add water to) mortar that has started setting
Why Brick Quality Affects Mortar Performance
Bricks with inconsistent dimensions (common from Bull's Trench kilns) force masons to use thicker mortar joints — sometimes 15–20mm instead of the standard 10mm. This uses 30–50% more mortar per wall. BBC1 wire-cut bricks maintain ±2mm dimensional consistency, keeping mortar joints uniform and mortar consumption predictable.
Water Content in Mortar
The water-cement ratio matters more than most contractors realise. Too much water makes mortar easy to work with but dramatically reduces strength after curing. The ideal mortar should be stiff enough that a trowel leaves a clean cut line.
For project-specific mortar recommendations, call +91 97280 65410.