---
title: "Masonry work, materials for 20 cum brickwork"
subject: "Building Technology"
chapter: 3
key: "semester_6/building_technology:brickwork-20cum-1to6"
source: https://www.bctengineer.com/q/semester_6/building_technology/brickwork-20cum-1to6
site: BCT Engineering
---

# Masonry work, materials for 20 cum brickwork

Building Technology · Chapter 3: Mortars & Masonry works

- Asked in: 2079 Asoj, 2+6 marks
- Video: [Brick Quantity calculation for house || How to calculate sand & Cement for Brick work](https://www.youtube.com/watch?v=AsqK3G4S2pM) — Civil Site visit
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/building_technology/brickwork-20cum-1to6
- Whole chapter: https://www.bctengineer.com/md/semester_6/building_technology/chapter-3

## Question

What do you mean by Masonry work? Calculate the quantity of materials for the construction of 20 cum. Brick masonry in 1:6 C/S mortar using Brick Size 230 mm × 110 mm × 55 mm.

## Short answer

For 20 m³ brickwork using bricks 230×110×55 mm, 10 mm joints, 1:6 mortar: 10684 bricks needed. Wet mortar = 5.133 m³, dry = 6.519 m³. Cement = 0.931 m³ (≈26.8 bags), sand = 5.588 m³.

## Answer

#### Masonry work
Masonry is the construction of a structure by building up units such as bricks, stones or concrete blocks, bonded together with mortar. When the units are bricks it is called brick masonry; when they are stones it is called stone masonry. Good masonry has a strong bond, plumb and level courses, fully filled joints and proper curing.

#### Materials for 20 cum brickwork in 1:6 mortar
**Given:** brickwork volume $= 20\ \text{m}^3$; brick size 230 mm x 110 mm x 55 mm (actual size, without mortar); mortar joint $= 10$ mm; mortar 1:6 (cement : sand).

**Step 1: Volume of one brick with mortar** (240 mm x 120 mm x 65 mm)

$$
0.24 \times 0.12 \times 0.065 = 0.001872\ \text{m}^3
$$

**Step 2: Number of bricks**

$$
N = \frac{20}{0.001872} = 10683.8 \approx 10684\ \text{bricks}
$$

**Step 3: Volume of bricks without mortar**

$$
10684 \times 0.23 \times 0.11 \times 0.055 = 14.867\ \text{m}^3
$$

**Step 4: Wet volume of mortar**

$$
20 - 14.867 = 5.133\ \text{m}^3
$$

**Step 5: Dry volume of mortar** (add 27% for dry bulk, voids in sand, wastage and shrinkage)

$$
5.133 \times 1.27 = 6.519\ \text{m}^3
$$

**Step 6: Cement and sand** for 1:6 (sum of ratio $= 7$)

$$
\text{Cement} = \frac{1}{7} \times 6.519 = 0.931\ \text{m}^3 = 1341\ \text{kg} \approx 26.8\ \text{bags (50 kg, 0.0347 m}^3\text{ each)}
$$

$$
\text{Sand} = \frac{6}{7} \times 6.519 = 5.588\ \text{m}^3
$$

**Answer: Bricks = 10684 nos.; cement = 0.931 m³ (about 26.8 bags); sand = 5.59 m³.**

## Check yourself

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

1. What is masonry?
   A. Concrete cast in formwork
   B. Timber framing
   C. Building with units such as bricks or stones bonded with mortar
   D. Only stone work without mortar
   Answer: C. Masonry joins units like bricks, stones or blocks with mortar. (Key point: Masonry definition)

2. For brick 230 x 110 x 55 mm with 10 mm joints, size with mortar is?
   A. 0.24 x 0.12 x 0.065 m
   B. 0.25 x 0.125 x 0.067 m
   C. 0.23 x 0.11 x 0.055 m
   D. 0.233 x 0.113 x 0.058 m
   Answer: A. Add 10 mm each way: 240 x 120 x 65 mm = 0.001872 m^3. (Key point: Brick with mortar)

3. Number of bricks in 20 m^3 is?
   A. 20/0.001265 = about 15810
   B. 20/0.001872 = about 10684
   C. 20/0.23 = 87
   D. 20 x 0.001872 = 0.037
   Answer: B. N = volume / volume of one brick with mortar. (Key point: Number of bricks)

4. Dry mortar is 6.519 m^3 in 1:6. Cement and sand are?
   A. 0.652 m^3 and 5.867 m^3
   B. 1.086 m^3 and 5.433 m^3
   C. 0.931 m^3 and 6.519 m^3
   D. 0.931 m^3 and 5.588 m^3
   Answer: D. Cement = 6.519/7 = 0.931 m^3; sand = 6/7 x 6.519 = 5.588 m^3. (Key point: Cement and sand)

## Related in Building Technology

- [Mortar for 10 m³ brickwork (1:4) numerical](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Amortar-10m3-1to4) — Building Technology, chapter 3
- [First class brickwork in 1:6 mortar numerical](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Amortar-first-class-1to6) — Building Technology, chapter 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
- [Mortar for 1.5 m³ brickwork numerical](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Amortar-1p5m3-1to4) — Building Technology, chapter 3
- [Specifications of brick masonry work](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Abrick-masonry-specs) — Building Technology, chapter 3, asked 2×
- [Materials for 10 m³ brickwork (1:6) numerical](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Amortar-10m3-1to6) — Building Technology, chapter 3

## Related in other subjects

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- [Brick and mortar for 230 mm wall (100 kN/m)](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Awall-eccentric-230mm-100kn-5m) — Concrete Technology and Masonry Structure, chapter 8, asked 7×
- [Materials for 115 m³ brick masonry 1:3](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Amaterials-brick-115m3-1-3) — Estimating and Costing, chapter 4
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