Thermowood decking: a simple guide to thermal modification

If you are planning a decking project and want something that looks beautiful, lasts longer, and requires less maintenance, you may have come across thermowood decking.

But what exactly is thermowood, and why is it becoming such a popular choice for modern outdoor spaces?

In this blog, we break it down in simple terms explaining how thermal modification works, the key benefits of thermowood decking, and why it is increasingly chosen by homeowners, designers, and landscapers across the UK.

The thermal modification process is what makes thermowood decking so unique.

In simple terms, timber is heated in a low oxygen environment to temperatures between 180°C and 220°C.

This process:

1. Removes moisture and natural sugars that attract decay
2. Minimises water absorption
3. Improves dimensional stability (less movement, warping or swelling)
4. Enhances durability without adding chemicals

Because the process is entirely natural, using only heat and steam, it creates a more sustainable and environmentally responsible decking solution compared to treated timber.