Is timber the building material of the future?

From Lego Engineering Club to Civil Engineer

First of all, we would like to briefly introduce our guest. Vadim is a structural engineer for urban timber structures and a specialist planner for preventive fire protection. It was precisely this feeling of creating something theoretically, then turning it into reality, that exerted a certain fascination on him, even as a child. A passion for Lego buildings increased his interest in architecture, so he studied civil engineering.
During his studies, he quickly noticed that older teaching methods were often used in this field. PV slides laid on top of the projectors, far out of date from the state of the art at the time. We all know those very particular professors whom not even the pandemic could dissuade from using their beloved slides. And we admit with a smile and a sigh: That will probably never change. But what about timber as a building material? Does everything stay the same here, too?

Vadim discovered his love for timber structures during his Master's degree program. At the same time, the topic of sustainable building moved into the focus of his interests. His current field of activity is mixed. A little marketing, a little structural engineering, advice, and fire protection. What is the best way to create a structure for a client's design? What do you have to pay attention to in the later planning? Plus, the approval and implementation planning – quite extensive, in our opinion!

Strengths of Natural Raw Material in Construction

Urban timber construction clearly shows its greatest strength when it comes to global warming. How can we reduce CO₂ emissions? As a sustainable material, timber is predestined for this, because reinforced concrete and steel require vast amounts of energy and raw materials to manufacture. Timber, on the other hand, can grow back, although to a limited extent.

The natural enemy of timber is? Fire, of course! However, timber structures are doing better than you might think. Because the charring rate is very easy to determine. This makes it easy to implement fire protection measures, which makes timber a very safe building material.

Timber has nothing to be ashamed of in terms of strength. When it comes to timber panels, it's all about the fiber. How does the fiber run, and where is the load application? Timber yields quickly at right angles to the grain. But if the loads act in parallel to the fiber, it shows its full strength. Innovative timber-based materials, such as BauBuche, for example, achieve a strength that can be compared to medium- to high-strength concrete. Fascinating, isn't it?

Cross-Laminated Timber Structure of Vineyard

Currently, almost every new building is a classic solid or reinforced concrete structure. On the other hand, single-family houses are mostly made of masonry. Does the price of timber structures play a role here? Vadim elaborates a little on this topic, because it is actually not that easy to answer.

It all depends on the way you work with the material. The prefabrication of the material in factory halls is a big plus. No matter if there's solid timber, glued-laminated timber, cross-laminated timber, or timber panel elements – the preliminary planning is often a bit more complex, but the construction process itself is much shorter. A building owner can use their building much earlier and thus generate more income by renting it. Opinions differ in this case. Some say it's the same price, some say it's five to ten percent more expensive. Others say it's even cheaper. But in principle, it is the overall view that counts. Vadim himself assumes that timber structures may be a small percentage more expensive in the future than conventional reinforced concrete structures.

Timber Construction in Germany

But why is so little timber still used to build in Germany? Vadim believes that this is due to the fact that timber is a relatively young material. At least, as we know it today. There is also a slight lack of empirical values, for example, in the case of multi-story buildings made of cross-laminated timber. Above all, there is a lack of expertise, as there is a certain reluctance to use the old "new" timber material. The knowledge is not yet too widespread here.

Although timber is already subsidized by the state as a building material, more would always be desirable, especially with regard to the climate problem. Many programs now are dedicated to the prefabrication of timber structures and, for example, the incorporation of timber as material in the field of robotics.

Myth of Timber Structures and Fire Resistance: How safe is timber?

Let's come back to the most famous myth. Wood burns; that cannot be dismissed out of hand. You can learn during your studies: Compared to other materials, such as steel, timber is actually much better in terms of fire protection. Vadim explains why.

• "I remember this little picture. Sadly, I can't find it again. It showed a building that had burned down. You saw a totally charred timber beam and on it was a steel beam, which was attached to it like spaghetti. I think that explains it pretty well."

Due to the burning process, a kind of protective layer forms on the surface area, which prevents further burning. It takes a lot of heat and a lot of time for timber to burn right into the interior. In terms of fire protection, a timber building is simply much safer than a steel one, as it is possible to calculate exactly what happens and when the material fails. To protect timber, it is helpful to add cladding, such as Promat panels or special coating.

Fire Safety Precautions

What about our forests: Is there enough wood?

Yes, at least if you consider our native forests. Around one cubic meter of wood grows back in Germany every second. Vadim explains to us that the high prices of timber are not necessarily related to the fact that we use too much wood ourselves. A large part of the wood extracted here is exported abroad. There is a high demand for it from China and the USA. Of course, it would be best if we can process and use our wood directly on site. Sometimes, so much wood is exported that it is necessary to import it again for building projects in one's own country – definitely a paradox. This urgently needs to be counteracted.

Timber Construction in Research

In the 21st century, the topic of sustainability came up again. People want to live more mindfully, and this is also becoming increasingly apparent in the construction industry. Timber, as a tried and tested raw material that has been with us for thousands of years, is ideal.
Research is currently being carried out into increasing the use of timber. Cross-laminated timber elements and glued-laminated timber require glue to hold together – and not a little of it. Unfortunately, this puts a huge damper on sustainability. But there is hope. Vadim tells us about a lignin-based glue. This is a component that is extracted from wood. Research is still in its infancy here, but it is a clear sign of innovation.

Future of Construction

Again, Vadim has answers to our question of where he sees the future of construction. He is firmly convinced that robotics and artificial intelligence will prevail. This is also an advantage for the prefabrication of components – not just those made of timber. He sees great potential in hybrid structures. He mentions "circular building" as particularly forward-looking. The term "cradle-to-cradle" is used; that is, a circular economy of raw materials. Many materials should be reused and not simply disposed of. Wood is cut down, a house is then made of it and, in the end, it should be returned to the earth as humus in the best case.

Vadim himself is currently working on glue-free solid wood. With sustainable glue, the material would produce even fewer pollutants – the optimum of what can be used sustainably, so to speak. Sounds good, doesn't it? The advantages of BIM are also associated with digitization.

Vadim, what is your favorite building?

• "For me as a Berliner, it's clearly the television tower. It's not made of timber or anything, but it's symbolically in my heart."

Berlin Television Tower - Berliner Fernsehturm

A classic structural timber engineer chooses a classic concrete structure as a favorite. We haven't had anyone say something like that before, but that's what makes our guest so likable.

Thank you, Vadim! Nice you to have you here.