Timber is one of the most versatile and widely used building materials around the world. However, like many natural materials, it has its vulnerabilities, particularly to weather, insects, and decay. Enter tanalised timber - a solution designed to enhance the durability and lifespan of wood products. In this comprehensive guide, we will explore what tanalised timber is, how it's made, its benefits, and practical applications.

What is Tanalised Timber?

Tanalised timber, commonly referred to as pressure-treated wood, is timber that has undergone a specific preservative treatment process to protect it from rot, fungi, and insect attack. The term "tanalised" comes from the proprietary name "Tanalith," a wood preservative commonly used in the treatment process. This type of timber is particularly valued for its enhanced durability, making it ideal for outdoor use and in situations where the wood is exposed to the elements or ground contact.

The Tanalisation Process

The process of tanalisation involves several key steps to ensure the timber is thoroughly treated and protected:

1. Preparation

Before treatment, the timber is typically dried to a specific moisture content. This step ensures that the preservative can be absorbed effectively into the wood fibers.

2. Preservative Solution

The timber is then placed in a large cylindrical chamber known as a treatment vessel. Here, it is subjected to a vacuum, which removes air from the wood cells. Once the air is extracted, the vessel is flooded with a preservative solution, typically containing copper, biocides, and other chemicals.

3. Pressure Treatment

The preservative solution is then forced deep into the timber by applying high pressure within the treatment vessel. This pressure ensures that the preservatives penetrate deep into the timber, offering long-lasting protection.

4. Drying

After the pressure treatment, the timber is removed from the vessel and allowed to dry. This drying process helps to fix the preservatives within the wood, ensuring they remain effective over time.

Benefits of Tanalised Timber

Tanalised timber offers a range of benefits that make it a popular choice for various applications:

1. Enhanced Durability

One of the primary benefits of tanalised timber is its increased durability. The preservatives used in the treatment process protect the wood from decay, rot, and insect damage, significantly extending its lifespan.

2. Versatility

Tanalised timber can be used in a wide range of applications, from garden furniture and decking to fencing and construction projects. Its enhanced resistance to the elements makes it suitable for both indoor and outdoor use.

3. Cost-Effective

While the initial cost of tanalised timber may be higher than untreated timber, its extended lifespan makes it a cost-effective choice in the long run. The reduced need for frequent maintenance and replacement can lead to significant savings over time.

4. Eco-Friendly

Tanalised timber can be an eco-friendly option when sourced from sustainable forests. The treatment process itself ensures that the timber lasts longer, reducing the demand for new wood and helping to conserve forest resources.

Practical Applications of Tanalised Timber

Given its durability and versatility, tanalised timber is used in a variety of practical applications:

1. Outdoor Structures

Tanalised timber is ideal for constructing outdoor structures such as pergolas, gazebos, and garden sheds. Its resistance to weather and insects ensures these structures remain sturdy and attractive for years.

2. Decking and Fencing

Decking and fencing are prime examples of where tanalised timber shines. These installations are constantly exposed to the elements, making the enhanced protection offered by tanalised timber invaluable.

3. Landscaping

In landscaping, tanalised timber is often used for raised garden beds, retaining walls, and other features that require longevity and resistance to moisture and soil contact.

4. Playgrounds

Safety and durability are paramount in playground construction. Tanalised timber offers a robust solution for play equipment, ensuring it can withstand active use and environmental exposure.

Caring for Tanalised Timber

While tanalised timber is highly durable, certain care practices can further extend its lifespan and maintain its appearance:

1. Regular Cleaning

To prevent the buildup of dirt, algae, and mould, regularly clean tanalised timber surfaces with a mild detergent and water. Avoid using harsh chemicals or pressure washers, as these can damage the wood.

2. Re-Treatment

Over time, the surface of tanalised timber may lose some of its protective properties. Applying a suitable wood preservative or stain every few years can help maintain its effectiveness and appearance.

3. Proper Installation

Ensure tanalised timber is installed correctly, with appropriate ventilation and drainage. This helps to prevent moisture buildup and prolongs the wood's lifespan.


Tanalised timber represents a significant advancement in the treatment and use of wood products. By enhancing timber's natural durability and resistance to decay, tanalisation opens up a world of possibilities for its application in construction, landscaping, and outdoor projects. Whether you're building a garden deck, erecting a fence, or crafting a custom outdoor structure, tanalised timber offers a reliable and long-lasting solution.

For those looking to make the most of their timber investments, understanding the benefits and applications of tanalised timber is crucial. As you embark on your next project, consider the advantages of this treated wood and how it can contribute to creating structures that stand the test of time.