---
title: "Manufacturing process of bricks"
subject: "Civil Engineering Materials"
chapter: 3
key: "semester_3/civil_engineering_materials:manufacturing-process-of-bricks"
source: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/manufacturing-process-of-bricks
site: BCT Engineering
---

# Manufacturing process of bricks

Civil Engineering Materials · Chapter 3: Clay Products

- Asked in: 2080 Bhadra, 3 marks; 2078 Bhadra, 3 marks; 2076 Asoj, 3 marks; 2074 Asoj, 2 marks (asked 4 times)
- Video: [From Clay to Brick: The Fascinating Process of Brick-Making!](https://www.youtube.com/watch?v=61G1rX-v0H4) — MFA Civil Engineering
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/manufacturing-process-of-bricks
- Whole chapter: https://www.bctengineer.com/md/semester_3/civil_engineering_materials/chapter-3

## Question

Describe the manufacturing process of (local burnt/fired clay) bricks, with a flow diagram where required.

## Short answer

Burnt clay bricks are made by preparing clay (weathering, tempering), moulding into shape (hand or machine), drying green bricks for 1–3 weeks, and burning at 900–1100 °C in clamps or kilns (e.g. Bull's trench, zigzag), followed by slow cooling.

## Answer

Burnt clay bricks are manufactured in four steps.

```text
 Clay preparation -> Moulding -> Drying -> Burning
 (dig, weather,      (hand or    (in air    (clamp or
  temper)             machine)    sheds)     kiln)
```

1. **Preparation of clay:** the top soil is removed and clay is dug out, cleaned of stones and roots, weathered for some weeks and then tempered with water into a uniform plastic mass.
2. **Moulding:** the clay is pressed into wooden or steel moulds by hand (ground or table moulding) or by machine (stiff-plastic or wire-cut).
3. **Drying:** green bricks are stacked in the open or under shade for 1 to 3 weeks until their moisture is below about 2%. This prevents cracking in the kiln.
4. **Burning:** done in clamps (temporary) or kilns such as the Bull's trench, Hoffman or zigzag kiln at 900-1100 °C. Dehydration, oxidation and vitrification take place and the bricks harden.

Finally, the bricks are cooled slowly, sorted and stacked.

## Check yourself

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

1. The correct sequence of brick manufacture is:
   A. Moulding, burning, drying, preparation
   B. Clay preparation, moulding, drying, burning
   C. Burning, moulding, drying, preparation
   D. Drying, moulding, preparation, burning
   Answer: B. Bricks are prepared, moulded, dried and finally burnt. (Key point: Order of steps)

2. Why are green bricks dried before burning?
   A. To make them red
   B. To increase absorption
   C. To avoid cracking in the kiln
   D. To harden by vitrification
   Answer: C. Moisture below about 2% prevents cracking. (Key point: Drying)

3. Bricks are burnt at about:
   A. 200-300 degrees C
   B. 400-500 degrees C
   C. 1800-2000 degrees C
   D. 900-1100 degrees C
   Answer: D. In clamps or kilns at 900-1100 C, dehydration, oxidation and vitrification harden the brick. (Key point: Burning temperature)

## Related in Civil Engineering Materials

- [Preparation of clay for bricks](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Aclay-preparation-for-bricks) — Civil Engineering Materials, chapter 3
- [Why bricks are widely used](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Awhy-bricks-widely-used) — Civil Engineering Materials, chapter 3, asked 3×
- [Manufacturing process of lime](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Amanufacture-of-lime) — Civil Engineering Materials, chapter 4, asked 2×
- [Cement manufacture with flow diagram](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Acement-manufacture-flow-diagram) — Civil Engineering Materials, chapter 5, asked 5×
- [Dry process of cement manufacture](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Acement-dry-process-flow-chart) — Civil Engineering Materials, chapter 5
- [Wet process of cement manufacture](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Acement-wet-process-flow-diagram) — Civil Engineering Materials, chapter 5, asked 4×

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