Thermal treatment of wood – Thermowood


Thermally treated wood improves the dimensional stability with 30 – 50%. Protects the wood against attack by rot and fungi. Protects the wood against most insects.
Provides the wood with a warm brown colour. It is treated without the use of chemicals or biocides. Improves the heat-insulation effect with 5 – 15%.


Thermal treatment removes part of the hemicellulose and other wood substances by heating it to 160 – 230 C in an open or a closed process either without pressure or with vapour pressure. Some processes use vacuum to prevent the plant and the wood from burning.

Moldrup hydro-thermal treatment uses both vacuum and high vapour pressure in a closed process.


Thermally treated wood should not be used in ground contact. Or in load-bearing constructions due to loss of strength. Or for protection against termites.

High quality wood with few knots is recommended for thermal treatment. Thermally treated wood is not colour stable and becomes brittle why sharp tools are required.