---
title: "Cement and sand for 100 m² plastering numerical"
subject: "Building Technology"
chapter: 3
key: "semester_6/building_technology:plaster-100m2-1to6"
source: https://www.bctengineer.com/q/semester_6/building_technology/plaster-100m2-1to6
site: BCT Engineering
---

# Cement and sand for 100 m² plastering numerical

Building Technology · Chapter 3: Mortars & Masonry works

- Asked in: 2075 Baisakh, 6 marks
- Video: [How to Calculate Quantity of Cement & Sand For Plaster](https://www.youtube.com/watch?v=pk8pAG5VxDg) — YAHYA SIR - PRODUCTIVE TALK
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/building_technology/plaster-100m2-1to6
- Whole chapter: https://www.bctengineer.com/md/semester_6/building_technology/chapter-3

## Question

Find out the quantities of cement and sand for 100 m² plastering area in 1:6 ratio if the thickness of plaster is 12mm.

## Short answer

For 100 m² plaster 12 mm thick in 1:6 mix: wet volume 1.2 m³, dry volume 1.524 m³. Cement = 0.218 m³ (about 6.3 bags of 50 kg); sand = 1.306 m³.

## Answer

**Given:** plastering area $= 100\ \text{m}^2$; thickness $= 12$ mm; mix 1:6 (cement : sand).

**Step 1: Wet volume of mortar**

$$
100 \times 0.012 = 1.2\ \text{m}^3
$$

**Step 2: Dry volume** (add 27% for dry bulk, voids in sand and wastage)

$$
1.2 \times 1.27 = 1.524\ \text{m}^3
$$

**Step 3: Cement and sand** (sum of ratio $= 7$)

$$
\text{Cement} = \frac{1.524}{7} = 0.218\ \text{m}^3 \approx 6.3\ \text{bags (0.0347 m}^3\text{ per bag)}
$$

$$
\text{Sand} = \frac{6}{7} \times 1.524 = 1.306\ \text{m}^3
$$

**Answer: Cement = 0.218 m³ (about 6.3 bags of 50 kg = 314 kg); sand = 1.306 m³.**

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is the wet mortar volume for 100 m^2 plaster 12 mm thick?
   A. 1.2 m^3
   B. 1.524 m^3
   C. 0.12 m^3
   D. 12 m^3
   Answer: A. Wet volume = area x thickness = 100 x 0.012 = 1.2 m^3. (Key point: Wet volume of plaster)

2. What is the dry volume used for the calculation?
   A. 1.2 x 1.27 = 1.524 m^3
   B. 1.2/1.27 = 0.945 m^3
   C. 1.2 + 0.27 = 1.47 m^3
   D. 1.2 x 7 = 8.4 m^3
   Answer: A. The dry volume is 1.27 times the wet volume. (Key point: Dry volume)

3. Cement quantity for dry volume 1.524 m^3 in 1:6 mix is?
   A. 1.524/6 = 0.254 m^3
   B. 1.524/7 = 0.218 m^3
   C. 1.524 x 6/7 = 1.306 m^3
   D. 1.2/7 = 0.171 m^3
   Answer: B. Sum of ratio is 7 so cement = 1.524/7 = 0.218 m^3 (about 6.3 bags). (Key point: Cement in 1:6)

4. Sand quantity for the same work is?
   A. 0.218 m^3
   B. 1.306 m^3
   C. 1.524 m^3
   D. 0.254 m^3
   Answer: B. Sand = 6/7 x 1.524 = 1.306 m^3. (Key point: Sand in 1:6)

## Close variants set in other exams

- [Cement and sand for 200 m² plastering numerical](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aplaster-200m2-1to5) — Building Technology, chapter 3, asked 2×

## Related in Building Technology

- [Cement-sand plastering and its types](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aplastering-process) — Building Technology, chapter 9, asked 3×
- [Mortar properties; cement and sand for 10 cum](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Amortar-quantity-10cum) — Building Technology, chapter 3

## Related in other subjects

- [Rate analysis: 12.5 mm plaster 1:3, per 100 m²](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Arate-plaster-12-5-1-3-ceiling) — Estimating and Costing, chapter 4
- [Materials: 100 m² plaster 1:6, 100 m³ PCC 1:2:4](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Amaterials-plaster-100m2-pcc-100m3-u) — Estimating and Costing, chapter 4
- [Rate analysis: 20 mm plaster 1:4 per 100 m²](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Arate-plaster-20mm-1-4) — Estimating and Costing, chapter 4, asked 3×
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