Sauna material: Thermowood alder panelling

Sauna material - thermowood alder panelling 


Thermowood is a thermal modified wood, invented and made by the Finnish. However, the technology was not brand new, since our ancestors had already known and used similar solutions. For example, they carbonized piles and pickets before digging them into the ground. Thanks to this method and therefore the lack of cellulose in the wood, feed for insects and pests, the lifetime of these underground parts could be multiplied.

This simple folk method was developed further and later patented by the Finnish wood products manufacturing industry and the Finnish National Research Institute. Final products made by this new technology are called Thermo Wood.

The wood is layed into a vacuum chamber for a couple of hours or even days, with a uniform temperature of 180 - 230°C. This procedure results in the change of the fibers of the wood. Wood is actually a long, jumbled chain of polymerized sugar molecules. The thermal modification demolishes a part ofthe hydroxyl groups in the cells.

Thanks to this method, the wood absorbs less water at the same rate of humidity, change in its size is minimized and its weather resistance is strengthened. This procedure is chemical-free and environmentally friendly. Woods with better features, like Finnish pine and spruce, beech, poplar, birch, alder and ash are used for this purpose. This is how a cheaper and more available exterior cladding material could replace tropical timber materials.


Benefits of Thermowood alder panelling:

  • it does not warp
  • it is not growing when it gets moisture
  • its tare weight is less 40% than the "bankirai" one
  • easy to work with, customized and easy to be screwed
  • generally spotted with knots but gives a beautiful texture comparing to other homogenous tropical species
  • in large surfaces can easily bear the extreme weather conditions
  • it can be used for various purposes with extra choices available


The most common uses of Thermowood alder sauna panelling are the following:

  • face coverings and blinds for buildings
  • terrace and balcony coverings
  • to edge pools and lakes
  • docks, piers coverings
  • building saunas in general, outdoor saunas and wellness spots and rooms
  • building garden pathways and pergolas
en hu de at sk cz