Thermowood is a registered trademark owned by the International Thermowood Association, a group of sixteen member companies from eight countries. This month we’ll look at Lunawood, maker of Thermowood products designed and manufactured in Finland.
Last year we explored Yakisugi, the centuries-old Japanese process in which wood is burned or charred on one side to make it more durable as a siding material. Heat treatment of wood has been used for millennia in various countries and cultures around the world. One successful heat treatment from the renewable and PEFC-certified forests of Scandinavia is Thermowood. Thermowood is a registered trademark owned by the International Thermowood Association, a group of sixteen member companies from eight countries. This month we’ll look at Lunawood, maker of a Thermowood products designed and manufactured in Finland.
Lunawood Thermowood uses Nordic pine and spruce with a unique appearance accented by round and butterfly-shaped knots. Like all Thermowood products, Lunawood’s thermal modification uses only heat and steam. The temperature inside the thermal chamber is slowly risen to 212°C and the entire process can last up to four days. The moisture percentage of the finished product is 4–7%.
The result is dimensional stability, durability, and sustainability. As it uses no chemicals, there is no harmful indoor air emissions or resin leakage. Lunawood makes products for facades, landscapings and interiors. For outdoor applications, Lunawood doesn’t require surface treatments – even in harsh weather environments – which makes it an ecologically friendly choice throughout its life. That said, Lunawood is not naturally termite-resistant, but can be treated with chemical treatments in termite-prone areas. Like all timber products, Lunawood will develop a naturally weathered look over time, turning grey upon exposure to ultraviolet light. If the naturally weathered look is not desired, the manufacturer recommends applying an oil or approved wood coating to help maintain the wood’s original appearance.
For indoor applications, Lunawood products claim to be safe and hygienic, even for allergy sufferers prone to wood-related reactions (often, allergies are not to the wood itself but to the added chemicals). Thanks to its resin-free properties, knots won’t show through paints or tints, even over time. As a resin-free product, it can even be used in saunas.
The products have a great look. See some samples at www.lunawood.com. But the sustainability at the company’s production units is equally impressive. With the goal of sending no wood waste to landfill, the Lunawood model is to establish “circular economies.” One example is the production of the Lunawood decking product.
“Planing dust” is an unavoidable side stream in the production of the various Lunawood products. The company uses this side stream in the production of Lunawood Thermowood Composite TWPC, which mixes Thermowood fibers (the planing dust) with Fortum Circo® recycled plastic. The resulting composite has the same features and benefits as Thermowood, making it the one of most stable wood composite decking materials on the market. The company claims it is exceptionally resistant to temperature changes and is suitable for all weather conditions. Plus, by reusing the planing dust, the company claims it is able to sequester more CO2 compared to burning it for energy or converting it to wood pellets for later burning.