Understanding Timber Seasoning: Methods, Purpose & Advantages

Timber, a crucial material in construction and engineering, requires a process called seasoning before it can be used effectively. In this article, we’ll delve into what timber seasoning entails, its various methods, and the purposes it serves.

What is Timber Seasoning?

When timber is freshly cut, it contains a significant amount of water, in the form of sap and moisture, accounting for nearly half of its dried weight. Before using it for construction, this moisture needs to be removed. The process of eliminating this water content is known as timber seasoning.

Purpose of Timber Seasoning

Properly seasoning timber serves several essential purposes, including:

• Facilitating Use as Fuel: Seasoned timber burns more efficiently when used as fuel.
• Reducing Weight for Transportation: Lowering moisture content decreases the weight of timber, making it more manageable for shipping.
• Protecting Against Infestations: Seasoning helps safeguard timber from fungal growth and insect infestations.
• Minimizing Warping and Cracking: Properly seasoned timber is less likely to warp, crack, or shrink.
• Preparing for Treatments: Seasoning readies the wood for processes like painting, preservation, and varnish application.
• Enhancing Physical Properties: It imparts greater hardness, stiffness, strength, and electrical resistance to the wood.

Methods of Timber Seasoning

There are two main methods for seasoning timber: natural and artificial.

1. Natural Seasoning

Description: Also known as air seasoning, this method relies on the natural air to dry timber.

Process: Timber pieces are arranged in stacks, either horizontally or vertically, with dry wood spacers to separate layers. These stacks should be shielded from harsh elements like wind, rain, and direct sunlight.

Advantages:

• Achieves moisture content of about 10-20% based on climate.
• Doesn’t require specialized supervision.
• Economical and straightforward.

Disadvantages:

• Drying process depends on natural conditions and can be hard to control.
• Surfaces may not dry uniformly, leading to potential issues.

2. Artificial Seasoning

Description: Artificial seasoning employs various methods like chemical, electrical, kiln, and water seasoning.

Reasons for Use:

• Reduces shrinkage, cracking, and warping.
• Offers controlled drying, minimizing fungal and insect risks.
• Ensures even drying of all surfaces.
• Shortens the seasoning period.
• Allows precise control of air circulation, humidity, and temperature.
• Makes timber more suitable for painting and gluing.

Methods of Artificial Seasoning:

i) Boiling: Timber is immersed in water and boiled for several hours, enhancing strength and elasticity.

ii) Chemical Seasoning: Wood is soaked in a salt solution, reducing moisture content.

iii) Electrical Seasoning: High-frequency alternating currents are used to expedite seasoning, though this method can be expensive.

iv) Kiln Seasoning: Wood is dried in an airtight chamber with heated, moisture-laden air.

v) Water Seasoning: Timber is fully immersed in running water for a period, washing away sap.

Each method has its own advantages and disadvantages, making the choice dependent on factors like budget, project requirements, and desired moisture content. By understanding these seasoning methods, we ensure that timber is optimally prepared for its intended purpose in construction and engineering projects.