Leading wood manufacturers develop special glulam solutions for outdoor use
In a time when wood is gaining even greater traction as a building material, it has been possible for the first time ever to get impregnated spruce glued timber approved for outdoor load-bearing constructions.
Behind the news is the glulam producer Lilleheden in Hirtshals and the wood and facade cladding manufacturer Superwood in Hampen, who have teamed up to develop the new product called Superwood Lilleheden Limtræ.
The two timber companies Lilleheden and Superwood have combined their core competencies in glulam and impregnation, respectively, and a bit of a novelty has come out of this. The two companies are now launching a thoroughly impregnated glulam product, which is approved for use in outdoor load-bearing structures without additional wood protection – something that has previously only been reserved for indoor glulam solutions.
– We are very happy about the collaboration with Superwood and that we can finally unveil our new joint product Superwood Lilleheden Limtræ. Lilleheden has been producing construction glued timber for more than 90 years, and we have only come this far because we continuously develop our production methods – among other things in collaboration with other skilled players in the wood industry. Our collaboration with Superwood is a good example of this, and we are proud that we can present a completely new solution for outdoor load-bearing structures, says Hans Henrik von Platen-Hallermund, CEO of Lilleheden.
Impregnation method maintains the strength properties of the wood
Often, processes and modifications will weaken the strength properties of the wood, which is why it has not previously been possible for Lilleheden to offer impregnated construction glued timber in spruce. However, Superwood has managed to change that, because as the only ones in the world they can impregnate spruce wood without weakening the wood’s strength properties.
– Superwood are the only ones in the world that can impregnate spruce wood, and this makes our new glulam product suitable for use in use class 3 according to DS/EN 335, which means that the wood can be used in places where it is exposed to wind and weather . We use a special method for the thorough impregnation, which penetrates all the way through the cross-section of the fir tree and leaves approx. 120 grams of wood preservative per cubic meters – enough to multiply the durability of the wood, and this happens at the same time without moistening the wood, says Ole Dalsgård Nielsen, CEO of Superwood, and continues:
– This of course has a positive influence on the product-specific EPD, which we have drawn up, to make it as simple as possible for contractors and builders to include the glulam in their LCA calculations. We have already delivered the new glulam product to constructions in several places in Scandinavia, where it has produced good results – and our project customers have received the product very well. Now we are ready to go wide with the product at our dealers in Denmark, Norway, Sweden and Germany, where we hope that it will be just as well received.
New aesthetic possibilities in load-bearing constructions
For the outdoor glulam constructions, Lilleheden uses spruce wood from the northern regions of Scandinavia, where the spruce grows slowly and thus achieves a high density and strength, which is necessary in the production of glulam.
– Despite glulam’s high strength and widespread use in load-bearing structures, it has previously been necessary to protect it for outdoor use. But the thorough impregnation means that the glulam does not have to be protected with, for example, a climate screen or paint. It offers new aesthetic possibilities, which we believe are needed at a time when buildings with load-bearing structures in wood are gaining ground, says Hans Henrik von Platen-Hallermund.
Hans Henrik von Platen-Hallermund adds that Lilleheden and Superwood still recommend end wood sealing and ongoing maintenance as with all other constructions.
Superwood Lilleheden Limtræ will be sold by Lilleheden and Superwood through dealers all over the country.