Improved natural durability

The thermal modification of wood improves the wood’s properties, thereby expanding the range of applications in which the wood can be used. As a result of thermal modification, high quality Finnish woods are transformed into durable and stable products for various demanding applications.

Weather Endurance

Due to the breakdown of hemicellulose (sugar chains), the wood no longer contains sufficient nutrients to support fungi which cause decay (KOMO certification).
LunaThermoD-class Thermowood has decay resistance class on 2 (durable) (EN 350-2). Wood products with decay resistance classes of 1 and 2 are suitable for outdoor use without any additional treatment.


Ipe Teak Cumaru Impregnated wood
A class
2 LunaThermo-D Iroko Merbau Western Red Cedar
Impregnated wood
AB class
3 LunaThermo-S Western Red Cedar(WRC) Siberian Larch Douglas Fir
4 Norway Spruce Scots Pine Douglas Fir
Birch Aspen European Ash

Timber in durability class 2 is suitable for exterior applications above ground without the need for further treatment.

Dimensional Stability

After thermal modification, the moisture content of the wood decreases to around 4-6 percent. The equilibrium moisture content is also permanently reduced as a result of thermal modification. The equilibrium moisture content of Thermowood is about half that of untreated wood.

As a result of this lowered equilibrium moisture content, Thermowood does not react to changes in humidity as drastically as untreated wood. In practice, this means that Thermowood is dimensionally stable and retains its shape far better than untreated wood.


Non-Toxic and Chemical Free

Lunawood Thermowood is a beautiful wood material produced using natural methods. only heat and steam are used in the manufacturing process and no chemicals are added whatsoever.
During the process, steam acts as a protective gas and prevents the wood from splitting and becoming damaged during treatment.

Improved thermal insulation

Tests have shown that the thermal conductivity on Thermowood is reduced by around 20-25% compared with untreated coniferous wood. As a result, Lunawood is an excellent choice of material for exterior doors, cladding, windows and saunas, to name just a few applications

Thermowood is resin-free

Resin is removed from the wood during the thermal modification process. As a result, the wood does not secrete resin even in high temperatures.