Siparila’s thermally modified Thermodeck terrace board combines an elegant appearance, excellent durability and minimal surface cracking.

The popular terrace material is getting an even better substitute

In recent years, larch has been a widely used terrace material in Finland. Its popularity is mainly based on its natural resistance to decay and its beautiful, light gray tone, which has been popular in construction.

Larch was imported from Russia, but now it is being replaced by an excellent Finnish innovation, thermally modified wood. Compared to larch, it is a better material in many ways. Siparila uses thermal modification to domestic spruce and pine, so, from now on, raw material availability and ecologic values are guaranteed.

In addition, the change is very positive for the builder and the end user, because thermally modified wood has the same good properties as larch – and even a little more. Siparila's thermally modified Thermodeck terrace board brings these advantages to terrace builders.

This is how Siparila’s Thermodeck meets the challenge:

  • Resistance. Thanks to thermal modification, the structure and composition of the wood changes so that the wood does not absorb as much moisture and is not susceptible to pests or small organisms. Thermally modified wood withstands weather conditions at least as well as larch.
  • No need for surface treatment. As with larch, thermally modified terrace board does not need surface treatments to guarantee durability. After installation, the surface is ready and will last for decades.
  • Ecology. The domesticity of the raw material, and the fact that no chemicals are needed in thermal modification process, guarantee that the product is environmentally friendly.
  • Gray tone. Thermal modification gives the wood the same graying properties as in larch. The graying process is even faster: thermally modified wood reaches its final gray shade in about a year, while the tone of larch deepens over about 2–3 years.

Dimensional stability and versatility as additional benefits

In addition to the things just mentioned, thermally modified wood has other great properties. Perhaps the most important of these is very good dimensional stability. It means that the wood doesn't crack like unmodified wood – like, for example, larch.

Thermal modification guarantees that the product is also functional indoors, including the rooms with wet facilities. Thermally modified wood can be used in making stylish, high-quality panels for offices and public spaces, creating an atmospheric look in different rooms at home, and building the interiors of sauna, from walls to ceilings and furniture.

Although thermally modified wood does not need surface treatment, there is no obstacle that you could not do it. If you want the appearance of thermal wood to stay longer in its original brown color, you can slow down its graying process with surface treatment.

The current thermally modified wood is the result of 20 years of research and product development

The thermal modification process was patented in Finland already in the late 1990s. In thermal modification, chemical and physical properties of wood are modified by using water vapor and heat, without any chemicals.

Thermal modification does not only affect the outer surface of the wood, as in impregnation treatment. Instead, the features of the wood improve throughout. The thermally modified wood is a durable and high-quality raw material for even demanding use.

Our thermally modified wood is manufactured in Finland, from Finnish pine and spruce. Therefore, its carbon footprint is significantly smaller than in larch, which usually is imported.

Through our parent company Thermory, we have extensive know-how in using thermally modified wood. Thermory is the world's largest manufacturer of thermally modified wood. The company has been producing it for 20 years and exports products to more than 50 countries around the world.

Thermally modified wood is the material of the future with many possibilities: it meets the requirements of builders, consumers and the environment.

Find out more about Thermodeck products here. The decking boards are available in concealed and top-mounted versions.

If you want to know more, feel free to contact us or directly our dealers.