Thermally Modified Timber

Thermally modified timber has gained real traction in architectural and landscape design thanks to its stability primarily, as well as its durability and the richness of its colour. If you are weighing up options for exterior or interior applications, understanding what this material is, as well as how it compares to other timber types, makes the decision so much easier on the whole. So let’s take a look at thermally modified timber: what it is, its key benefits and uses, and how it compares to untreated and treated wood.

What Is Thermally Modified Timber?

Essentially, it is a kind of timber that has been modified by heating wood to high temperatures in a low-oxygen environment. Usually the temperatures go from at least 160c but can get as high as 220c. This process alters the wood at a molecular level, reducing its hygroscopicity – how much moisture it can absorb – and improving dimensional stability without using chemicals at any point in the process.

The Modification Process

There are generally three main phases to the modification process for thermally modified timber. First is the drying phase, when moisture is removed from the wood in a controlled environment. After that comes the heat treatment part of the process, where the timber is heated to its target temperature in low oxygen to prevent combustion. After that, the timber is cooled, re-moisturised and conditioned to reach a workable moisture content. It’s a simple but hugely transformative process.

Performance Benefits

There are a huge number of performance benefits to thermally modified timber, including:

Improved Durability

Thermal modification breaks down certain organic compounds that decay-causing fungi rely on, resulting in enhanced natural durability. Many thermally modified products reach durability levels comparable to hardwood species traditionally used in outdoor settings.

Stability

It also tends to have an exceptional level of stability, because the timber absorbs much less moisture. This means it is less prone to swelling, shrinking, cupping and warping, and makes it ideal for harsh conditions.

Rot & Fungal Resistance

The reduced moisture level makes the wood an inhospitable environment for fungal growth and rot, great news wherever you are using the wood.

Rich Colour

Finally, it has a very rich and uniform colour which resembles some of the more exotic hardwoods.

Best Uses

Thermally modified timber is generally best used for a wide range of applications, including cladding, decking, screen, soffits and eaves linings, and interior wall and ceiling linings too.

Care & Maintenance

Thermally modified timber can be left unfinished, where it will weather to a natural gray. If you want to maintain the darker colour, however, you can apply a high-quality exterior oil or coasting, and refresh the finish periodically.

If you would like to try thermally modified timber, Timbeck supplies an extensive range of products, from cladding to screening systems. If you are after standout stability, durability and a refined aesthetic, it’s a material worth integrating into your next project for sure. Explore more and find out more today about thermally modified timber.