Wood is one of the oldest and most versatile building materials, appreciated for its natural beauty, warmth, and durability. However, wood is also susceptible to moisture, pests, and decay, which can compromise its structural integrity and aesthetic appeal.
To address these challenges, various wood treatments have been developed over the years, ranging from chemical preservatives to surface coatings. One of the most promising and eco-friendly methods is thermal treatment, which involves heating the wood in a controlled atmosphere to modify its chemical and physical properties. In this article, we will explore the benefits, properties, and applications of thermally treated Nordic pine, a popular wood species from northern Europe.
The process of thermal treatment
Thermal treatment is based on the principle of pyrolysis, which is the decomposition of organic matter by heat in the absence of oxygen. When wood is heated to a temperature of 160-240°C for several hours, its cell structure changes, resulting in reduced moisture content, increased stability, and altered color and texture.
The heat also breaks down the hemicellulose and lignin components, which are responsible for the wood's susceptibility to decay and insect attack. The result is a more durable, weather-resistant, and aesthetically pleasing material, with a distinctive dark hue that varies from light brown to charcoal grey depending on the temperature and duration of the treatment.
The thermal modification process can be customized according to the desired properties and applications of the wood, such as decking, cladding, flooring, furniture, and decorative items.
Properties of thermally treated Nordic pine
Nordic pine, also known as Scots pine or Pinus sylvestris, is a common softwood tree species in Scandinavia, Russia, and other parts of Europe. It is valued for its straight grain, fine texture, and light color, which make it suitable for a wide range of uses, from construction to joinery.
However, untreated Nordic pine is not very durable, as it is prone to cracking, warping, and rotting when exposed to moisture and insects. By contrast, thermally treated Nordic pine has several advantages:
- Improved dimensional stability: The heat treatment reduces the wood's moisture content and hygroscopicity, making it less sensitive to changes in humidity and temperature. This means that thermally treated Nordic pine is less likely to swell, shrink, or distort over time, which improves its performance and longevity.
- Enhanced resistance to decay and insect attack: The breakdown of hemicellulose and lignin during thermal treatment creates a less favorable environment for microorganisms and pests, reducing the risk of decay and infestation. This means that thermally treated Nordic pine can be used in harsh environments and exposed to water, soil, and air without significant degradation.
- Unique color and texture: The thermal modification of Nordic pine results in a rich, dark color that is both natural and elegant. The color varies depending on the treatment parameters and the wood's original color, but it is generally darker than the original and has a distinctive pattern of darker and lighter stripes that add character and depth to the wood. The texture of the wood is also slightly altered, becoming smoother and more uniform than untreated wood.
We have chosen to use thermally treated Nordic Pine for all our barrel saunas because of all the benfits it provides. Not only will your sauna look amazing, it will last you a lifetime!