Thermal Modification


Between our expert wood scientists and exceedingly high sourcing standards, that’s all we need to create products that set the bar for rot resistance and longevity.

In this whitepaper, we provide a close look at how thermally-modified wood is made and the benefits it offers to modern construction. We also discuss the key considerations when specifying thermally-modified wood for your next project.

See the Benefits of Thermally-Modified wood

Thermal modification gives our products many advantages

Highest durability class

Most dimensionally stable in changing weather conditions

Does not become as hot in the sun

Chemical-free modification

Lower moisture content makes the material lighter

No need to handle our products as hazardous waste

Thermal modification penetrates far below the wood’s surface

Unlike chemical impregnation, thermal modification enhances the wood throughout, not just the outer surface. The result is boards that are stable and durable in every sense. At Thermory, we believe product quality is paramount, so we work hard on mastering our technology and innovate to stay ahead.

Thermo-pine board

Thermal modification requires a master’s dedication and skilful hand

The thermal modification process takes place in a heating chamber with special sensors, controlled by experienced specialists using computer.

Thermory’s quality is ensured by a special thermal modification process developed based on 20 years of experience, which varies by species and purpose of use. The principle is the same: the moisture level of the wood is reduced to 0% over a period of 35-46 hours and then the temperature is raised to the necessary level, followed by the cooling and misting of the wood. At all times during the thermal modification process, only temperature and steam are used. Heat triggers physical and chemical reactions in the wood and we control the process by adjusting the moisture.

Thermory thermo kiln

The peak temperature depends on the type of wood and where the thermally modified wood product is to be used

  • intense thermal modification: the temperature is at least 215 degrees, which makes our wood products ideal for use in outdoor settings
Thermo-pine decking and cladding (Stavanger)
  • medium thermal modification: the peak temperature is 190 degrees, which is suitable for wood for indoor use
Restaurant Tuljak Ash Flooring

Thermal modification makes wood more durable and stable

During the thermal modification process, the wood’s density decreases and its structure changes, which gives our thermally modified wood products many advantages:

  • Wood’s physical and chemical properties change during thermal modification. When it’s heated, the wood releases moisture and its chemical composition is transformed.
  • Thermal modification lowers the wood’s absorbency, meaning that exposure to moisture no longer causes it to swell as much. It also improves the dimensional stability, so the wood expands and contracts less in outdoor conditions.
  • The lower internal stresses found in thermally modified wood also reduce material consumption during construction.
  • Wood’s biological resistance increases as the nutrients in wood are modified during thermal modification, becoming less available to pests and microorganisms. This increases the durability of the wood in outdoor conditions and ensures that it does not need to be impregnated with toxic substances for protection.
  • The heat and sound insulation of thermally modified wood is superior to that of natural wood by as much as 30%.
  • Thermally modified wood has a lower weight and density, making the wood easier to work with mechanically.
  • Thermally modified wood has a beautiful, deep color. This can offer sustainability benefits, for example by making thermally modified ash a great alternative to tropical hardwood.
  • As no chemicals are used in the thermal modification process, our thermally modified wood products are safe and there’s no need to handle them as hazardous waste after use.
Thermal modification steam

Our thermally modified wood products are tested

We know our thermally modified wood products are top of the line. If the correct installation techniques are used, they will last for decades. Our products are consistently proven through third-party test results.


Your next project with Thermory

Once you use Thermory, you’ll never look at wood the same way again. For decking, cladding, porch flooring or anything else you use wood for, Thermory sets the bar for beauty and longevity.

Send enquiry

Leave a lasting impact

Our boards are a stunning combination of natural beauty and enhanced function. The results of our innovative process are products that are highly rot resistant without sacrificing strength or pliability. Products with extraordinary longevity and rich, beautiful color. We have one goal: creating lasting impact.

Thermory thermally modified wood is suitable for interiors and exteriors, homes and, thanks to its durability, public areas. Facades, decks and balconies, saunas, swimming pool areas, flooring, walls and roofs.

Learn more about our thermally modified wood products