Interview: Building with wood from one’s own forest
The construction industry has long been occupied with a local supply chain model, and not just in the abstract. Urban Jung, General Manager of Lehmann Holzwerk, has also noticed clear evidence of this trend. Increasingly, he is being asked by customers to process round timber from their own forests. This includes municipalities, for instance, for the construction of public buildings.
Urban, paint the picture for us – I have an area of woodland and want to use the raw material to build a local school or another construction project?
URBAN JUNG That’s it precisely. In the context of reducing carbon emissions, we are finding that wood is increasingly being used in building work, but that there is also a desire to use the available timber resources belonging to a municipality or company for a specific construction project.
So how does this request then reach Lehmann Holzwerk?
It’s often a public sector building contractor or a timber construction specialist who asks us to process their round timber. This means that we are asked to do the sawing as well as the relevant processing, whether that’s planing or finger jointing.
So you also quote for processing work. Who is then subsequently responsible for delivery and assembly, for example for a facade?
That would be the timber construction company carrying out the work. This could be our associate company Blumer Lehmann or of course any other timber construction company.
Are there any completed projects where we were able to carry out this kind of work?
Yes, there are plenty. For example, we’re currently in the process of supplying the timber for a new indoor swimming pool in Appenzell, for the Rietwis sports complex in Wattwil and for extensions to the AgroVet-Strickhof centre for education and research in Lindau, Zurich.
Appenzell indoor swimming pool, visualisation of the exterior Equilibre © nightnurse images, Zurich
What’s the benefit of having timber supplied this way? Is it not a much more laborious and expensive process for the client?
No, not at all. The advantage for the customer is that they can put their wood straight to good use and they hold clear documentation on where the wood comes from. Resale margins are also cut out of the process. When there are large amounts of storm-damaged timber around, this is a convenient way to use valuable raw materials.
You touch upon timber quality grades. Can customers simply order timber in the required quality grade and that’s what you deliver? Or what does the process ideally look like?
It doesn’t tend to be as simple as that. Wood is and shall remain a natural product. An ideal process for us is when the customer or timber construction specialist doing the processing approaches us as early as possible. We can then work together to determine the ideal ‘yield’ from the round timber available, as this depends on the quality required. As experts in sawing, we are without doubt the go-to people in this respect, with the greatest wealth of experience and good judgement. Depending on how the timber will be used and the quality required, such as with no knots or discolouration, further processing in our finger-jointing mill may be an option, or else the resulting qualities are put to a range of appropriate uses.
Very interesting. Let’s look again at finger jointing. As you know, we have been able to supply fingerjointed products since last year. What advantages does this hold for the customer? And what products do we offer them?
Adding finger jointing as a stage in the process allows us to influence the quality of the wood according to how it will be used. This means that we can take the wood that has grown and cut out defects, to a greater or lesser extent, before reassembling the parts remaining. This also allows lengths to be selected as required, from 3 metres to 6 metres. As a result, we can fulfil almost any requirements with our sawn timber. Our standard products include finger-jointed slats, rough-planed timber, facade solutions, weatherboarding, cladding with a visible groove, rhomboid cladding as well as interior panelling – virtually anything is possible. Facade cladding is available in the different quality grades N1 and A, free of knots or rift sawn or quarter sawn on request, and is laminated using a formaldehyde-free PU adhesive. Different standard profiles as well as a range of bespoke profiles, various types of wood and surface treatments are available to choose from.
Urban, thank you for sharing this with us, it sounds like a fascinating area to work in. What do you personally think the future holds for wood as a raw material and for building?
Timber will be the building material of the future, for many different reasons. It is a very attractive raw material for architects as it can be used to create virtually any shape you like (see Free Form by Blumer Lehmann). Its tactile surface is also very inspiring and radiates a sense of warmth. Wood is the only raw material that regrows locally, sequesters carbon and requires very little energy for processing. Wood from sustainably managed forests therefore offers all the benefits a future building material would need.