1. What is Sand and Cement Render?

Sand and cement render is a mixture used to coat walls and other surfaces in construction. It provides protection and a smooth finish to masonry surfaces. The ratio of cement to sand affects the strength and workability of the render.

2. How Does the Calculator Work?

The calculator uses these formulas:

Where:

• 1.33 — Factor accounting for material compaction and waste
• 1440 — Density of cement (kg/m³)
• 1600 — Density of sand (kg/m³)
• Ratio — Cement to sand proportion (e.g., 1:4 means ratio = 4)

3. Importance of Accurate Material Calculation

Details: Proper calculation ensures you purchase the right amount of materials, avoiding waste or shortages. It also helps maintain the correct mix ratio for optimal render quality.

4. Using the Calculator

Tips: Measure the area accurately in square meters. Typical render thickness is 10-20mm (0.01-0.02m). Common ratios are 1:4 to 1:6 for external renders.

5. Frequently Asked Questions (FAQ)

Q1: What's the typical cement to sand ratio for render?
A: For external walls, 1:4 to 1:6 (cement:sand). For internal walls, 1:3 to 1:5.

Q2: How much water should I add?
A: Enough to achieve a workable consistency - typically about 20-25% of the total dry mix weight.

Q3: What thickness should I use?
A: External renders are usually 15-20mm thick, applied in two coats. Internal renders are often 10-15mm.

Q4: Can I add lime to the mix?
A: Yes, lime improves workability and reduces cracking. A common mix is 1:1:6 (cement:lime:sand).

Q5: How long does render take to dry?
A: Initial set occurs in 24-48 hours, but full curing takes 28 days. Protect from rapid drying in hot weather.