---
title: "Why timber is used; seasoning method"
subject: "Civil Engineering Materials"
chapter: 7
key: "semester_3/civil_engineering_materials:seasoning-method-and-timber-use"
source: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/seasoning-method-and-timber-use
site: BCT Engineering
---

# Why timber is used; seasoning method

Civil Engineering Materials · Chapter 7: Timber

- Asked in: 2072 Chaitra, 4 marks
- Video: [Timber part 2 - Seasoning of timber](https://www.youtube.com/watch?v=LXUBrzNK5xk) — Civil tree
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/seasoning-method-and-timber-use
- Whole chapter: https://www.bctengineer.com/md/semester_3/civil_engineering_materials/chapter-7

## Question

Why and how is timber being widely used in all engineering works? Describe briefly the method of seasoning timber.

## Short answer

Timber is widely used because it is light, strong, insulating, renewable, workable, and economical. Seasoning lowers moisture to 10–15% by air drying (stacked with spacers under cover), water immersion, or kiln drying with controlled hot air, preventing decay and distortion.

## Answer

#### Why timber is widely used
Timber is used in all engineering works because it is:
- readily available and renewable, and easy to cut, shape, join and finish with simple tools;
- light in weight but has high strength-to-weight ratio, good in tension and bending;
- a poor conductor of heat, sound and electricity, and so comfortable and insulating;
- good at absorbing shock and vibration, and resistant to some chemicals;
- cheaper than steel in many places (Nepal has plentiful forests), and attractive in appearance;
- reusable and easy to repair, and suitable for doors, windows, roofs, floors, formwork, scaffolding, bridges and furniture.

#### Seasoning method (brief)
**Seasoning** removes moisture to 10-15% so that timber does not shrink, warp or decay.
1. **Natural (air) seasoning:** the converted timber is stacked on raised platforms under a shed in a well-ventilated place, with spacers between the layers, for 6 months to 2 years.
2. **Water seasoning:** logs are immersed in running water for 2-4 weeks to wash out the sap, then dried in air.
3. **Kiln seasoning:** timber is stacked in a chamber with hot air of controlled temperature and humidity for 4-10 days; this is quick and controlled.
4. **Chemical and electrical seasoning** are also used in special cases.

## Check yourself

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

1. One reason timber is widely used in engineering is
   A. It is heavier than steel
   B. It conducts heat well
   C. High strength-to-weight ratio and ease of working
   D. It is immune to fire
   Answer: C. Light, strong, workable. (Key point: Why timber used)

2. Timber is a
   A. Good conductor of electricity
   B. Good conductor of heat
   C. Good only for sound
   D. Poor conductor of heat, sound and electricity
   Answer: D. Insulating. (Key point: Insulation)

3. Air seasoning stacks converted timber
   A. On raised platforms under shed with spacers, 6 months to 2 years
   B. In kiln for days
   C. Under water
   D. In sun on ground
   Answer: A. Natural stacking. (Key point: Air seasoning)

4. Kiln seasoning takes
   A. 6 months
   B. 4-10 days with controlled hot air
   C. 2-4 weeks in water
   D. Years
   Answer: B. Quick and controlled. (Key point: Kiln)

## Related in Civil Engineering Materials

- [Seasoning of timber and its necessity](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Aseasoning-meaning-necessity) — Civil Engineering Materials, chapter 7, asked 8×
- [Methods of seasoning timber](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Amethods-of-seasoning-timber) — Civil Engineering Materials, chapter 7, asked 2×
- [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×
- [Why plastics are widely used](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Awhy-plastic-used-extensively) — Civil Engineering Materials, chapter 10, asked 3×
- [Natural versus artificial seasoning](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Anatural-artificial-seasoning) — Civil Engineering Materials, chapter 7
- [Defects caused by seasoning](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Aseasoning-defects-timber) — Civil Engineering Materials, chapter 7

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