Refined wood for defined needs 

thermowood

Stora Enso ThermoWood is thermally modified timber of which the manufacturing process is based on the use of high temperature between 190°C/374°F and 212°C/414°F in a steam environment.

It is produced from Nordic Pine or Spruce which has been sourced from PEFC certified forests. ThermoWood is produced with strict quality control through the whole process. It is certified with KOMO quality certification and produced within the ISO 9001 quality system, which is audited by Inspecta Ltd. Since no chemicals are added during the process ThermoWood only contains substances from the natural wood. When newly treated wood is exposed to rain, small amounts of water soluble organic compounds released during the process may be washed out. As no chemical substances are added during the process, no chemical leaching will occur. In addition, as the resin is removed during the process, the problem of resin leakage through the knots or pitch pockets is eliminated. Another improvement is in the insulation properties of the final material, the process leads to a reduction in thermal conductivity.  In most cases energy needed for the ThermoWood process is produced by burning bark and wood waste. The energy for the production of Thermowood is mainly needed for drying which accounts for 80% of the heat energy used. The production of ThermoWood consumes about the same amount of electricity as is used in normal kiln drying of sawn timber.

The ThermoWood treatment process is patented and the trademark is owned by the International ThermoWood Association. The technical specifications of ThermoWood are defined in the CEN/TS15679 2008 Thermal Modified Timber, definitions and characteristics.

The characteristics of Stora Enso ThermoWood

  • Improved biological durability – no chemicals used
  • Excellent dimensional stability
  • Consistent treatment throughout the whole cross-section
  • Totally integrated production and quality control
  • Raw material sources from certified forests
  • Available in both Pine/Redwood and Spruce/Whitewood

Stora Enso ThermoWood is a material for demanding end uses, great for products affected by changing climatic conditions such as exterior claddings, fascia boards, windows and garden products. For the interior, the attractive appearance, stability and removal of resin makes the product a good choice for use in saunas, interior panels, furniture and flooring.

Stora Enso ThermoWood is produced according to quality guidelines based on “fit for purpose grading” and the quality rules drawn up by the Finnish ThermoWood association. Stora Enso ThermoWood in many cases exceeds the requirements in areas such as shakes and knots.