The Science

Thermal modification is a high-precision process that enhances the durability and stability of wood using only heat and steam, no chemicals. Developed over decades of research, including by leading manufacturers like Thermory, the process begins by reducing the moisture content of the wood to nearly 0% over a period of 35 - 46 hours. Once dry, the wood is heated to high temperatures (typically between 160°C and 215°C) in a controlled, oxygen-free environment to prevent combustion. During this stage, chemical and physical changes occur at the cellular level: sugars are broken down, which significantly reduces the wood’s ability to absorb moisture or support decay. After reaching the target temperature, the wood is then carefully cooled and reconditioned with steam to balance its internal moisture and reduce brittleness.

The Result

A timber product that’s more durable, dimensionally stable, and resistant to decay, without the need for preservatives or harmful chemicals. The treatment increases the wood’s resistance to rot, fungi, and insects resulting in an improved durability, ideal for external use. It enhances the wood’s stability, making it less prone to warping, cupping, or shrinking with changes in humidity. No chemicals are used in the process, and the wood remains 100% natural, making it an environmentally responsible choice. The improved properties extend the service life of the timber, offering better value over time and a beautiful finish as the process enhances the natural grain and gives the wood a rich, dark colour that weathers elegantly over time.

How Does This Benefit You?

When you choose thermally modified timber, you’re investing in a material that performs better, lasts longer, and requires less maintenance. Its enhanced durability means your decking, cladding, or fencing will resist rot, decay, and insect damage, reducing the need for costly repairs or replacements. Improved dimensional stability ensures a cleaner, more precise finish that holds its shape over time, even in challenging weather conditions. Plus, with its rich colour and refined grain, thermally modified wood offers a premium look that elevates any outdoor or architectural project. Whether you’re a homeowner, landscaper, or builder, you get a product that delivers exceptional value, sustainability, and peace of mind.

Our Thermally Modified Timber Products

At Southgate Timber, we proudly stock a premium range of thermally modified timber products, including:

• Thermo-Ash Decking: A stunning hardwood decking solution known for its strength, sleek appearance, easy to install end-matched system, and long-lasting performance.
• Thermo Ayous Cladding & Fencing: A lightweight, beautiful cladding option with a contemporary aesthetic and excellent resistance to decay, also available as fencing.
• Thermowood Cladding & Fencing: Made from Nordic Pine, Thermowood is a cost-effective and sustainable choice for exterior timber projects.
• Radiata Pine Cladding: Thermally modified Radiata Pine offers an attractive, stable alternative to traditional softwoods, perfect for modern cladding applications.

Ready to Build with Thermally Modified Timber?

Whether you’re creating a sleek garden room, a durable deck, or a weather-resistant fence, our range of thermally modified timber has you covered. Explore our full selection online or get in touch with our team for expert advice.