--- title: "Seasoning of timber and its necessity" subject: "Civil Engineering Materials" chapter: 7 key: "semester_3/civil_engineering_materials:seasoning-meaning-necessity" source: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/seasoning-meaning-necessity site: BCT Engineering --- # Seasoning of timber and its necessity Civil Engineering Materials · Chapter 7: Timber - Asked in: 2081 Baisakh (new course), 1.5 marks; 2081 Kartik (new course), 1.5 marks; 2080 Bhadra, 2 marks; 2078 Kartik, 2 marks; 2076 Chaitra, 2 marks; 2073 Shrawan, 1 marks; 2069 Chaitra, 2 marks; 2075 Asoj, 1 marks (asked 8 times) - Video: [Seasoning of Timber (Lecture 7)](https://www.youtube.com/watch?v=NrNAQ6ajKjw) — Knowledge Centre - 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-meaning-necessity - Whole chapter: https://www.bctengineer.com/md/semester_3/civil_engineering_materials/chapter-7 ## Question What does seasoning of timber mean and why is it necessary (objectives of seasoning)? ## Short answer Seasoning is the controlled removal of moisture from freshly felled timber to about 10-15% moisture content. It reduces weight, increases strength, prevents shrinkage and decay, improves paint absorption, and ensures stability and durability. ## Answer **Seasoning** is the process of removing moisture (sap and water) from freshly felled timber to a suitable level (about 10-15% moisture content, or equal to the air-dry condition of the place of use) in a controlled way, so the timber becomes stable and durable. #### Why seasoning is necessary 1. **Reduces weight** of timber, so it is easier to handle, transport and use. 2. **Increases strength:** dry timber is stronger, harder and stiffer than green timber. 3. **Prevents shrinkage, warping and cracking** after use: moisture loss is completed before fixing, so the shape stays. 4. **Resists decay:** fungi and insects need moisture (above about 20%) to live, so dry timber lasts longer. 5. **Better for treatment:** dry timber absorbs paint, varnish, polish and preservatives more easily and holds them. 6. **Better for gluing and fastening:** nails, screws and adhesives hold better. 7. **Improves workability** and finish; reduces electrical conductivity, and makes it lighter in colour. 8. **Prevents fungal stains** and gives a uniform appearance. Thus seasoned timber is more economical, strong and durable. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. What is seasoning of timber? A. Coating timber with chemical preservatives B. Soaking timber until it is saturated C. Cutting logs into planks D. Controlled removal of moisture from freshly felled timber to about 10-15% Answer: D. Seasoning is controlled drying to an air-dry moisture level. (Key point: Meaning of seasoning) 2. Why does seasoned timber resist decay better? A. Fungi and insects need moisture above about 20% to live B. Seasoning kills all fungi permanently with heat C. Dry timber becomes chemically inert D. Seasoning adds a preservative coating Answer: A. Below about 20% moisture fungi cannot thrive. (Key point: Decay resistance) 3. Why is timber seasoned before fixing in a structure? A. To make it heavier and easier to fix B. Moisture loss is completed beforehand, so it will not shrink, warp or crack after use C. To increase its moisture for flexibility D. To make it swell inside walls Answer: B. Pre-drying prevents later shrinkage and warping. (Key point: Dimensional stability) 4. Compared with green timber, seasoned timber is A. Weaker but lighter B. Stronger but heavier C. Stronger, harder and lighter D. Equal in strength but darker Answer: C. Drying increases strength and reduces weight. (Key point: Effect on strength) ## Related in Civil Engineering Materials - [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 timber is used; seasoning method](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Aseasoning-method-and-timber-use) — Civil Engineering Materials, chapter 7 - [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 - [Define seasoning, need, methods](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Aseasoning-defined-seasoning-s) — Civil Engineering Materials, chapter 7 - [Uses of timber and modified timber](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Auses-of-timber-modified-timber) — Civil Engineering Materials, chapter 7 ## Related in other subjects - [Importance and objectives of water supply](https://www.bctengineer.com/question.md?key=semester_5%2Fwater_supply_engineering%3Aimportance-objectives-ws) — Water Supply Engineering, chapter 1 - [Importance and objectives of wastewater disposal](https://www.bctengineer.com/question.md?key=semester_6%2Fsanitary_engineering%3Aobjectives-wastewater-disposal) — Sanitary Engineering, chapter 6, asked 3× - [Shoring, its objectives and types](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Ashoring-objectives-types) — Building Technology, chapter 8 - [Objectives of shoring; dead shore](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Ashoring-dead-shore) — Building Technology, chapter 8