When you think of skyscrapers you usually picture a huge monolith like structure made of concrete, metal, and glass. However, as we move into a more eco-conscience world, we have to start looking for solutions that will reduce a building’s carbon footprint, something new, creative and innovative.
The answer might just lie in timber. That’s right, in the future, skyscrapers may be made of a material we have used for millennia, wood!
Yet the question arises – after years of using steel and concrete, why should we consider using wood to build something like a skyscraper? And cut down more trees?
There are some major benefits to using wood as a construction material, one of them being carbon capture. As it stands, modern-day skyscrapers produce large amounts of carbon emissions. If we use wood to build them we can cut down the carbon footprint of a skyscraper by almost 75%. And if we use the responsibly sourced wood, we can create materials with robust fire resistance, reduce building times and create lighter overall structures.
Is it possible to build a high rise building with wood?
While it is possible to build a structure with wood, is it plausible to build something as tall as a high rise building with it?
New materials have been created in order to achieve this feat. For the weight bearing building framework, glue-laminated timber—pieces of lumber bonded together into massive beams and columns will be used. Internal walls and floors will be built with cross-laminated timber (CLT), also called super-plywood. CLT is made in a factory environment using sustainably sourced timber (wood from young, dead or thin trees).
CLT is usually made from Spruce; however, other types of wood like cots pine, larch and Douglas fir can be used too. At the factory the wood is planed and then kiln-dried to reduce the moisture content. This conditioned wood is then stacked into layers on top of each other. Each layer is basically glued at 90 degrees to each other and hydraulically pressed to each other, making for a stable material that is light and is almost as strong as steel and concrete. Wood panels are then sliced into exact dimensions in the factory and can slotted into place on the building site within a matter of hours.
Because of its strength, creating high-rise buildings out of CLT material becomes plausible.
At the moment, the tallest wooden building in the world is the 173 foot Tall Wood Residence in Vancouver . However, there are a number of other towers under construction, which will be higher than the Vancouver building, like the 264-foot all-timber tower in Norway. There are also other tall timber structures in construction in The Netherlands, Scandinavia and Canada.
This attests to the feasibility of building a high rise tower with this material.
What about fire resistance?
It may come as a surprise but unlike unprotected steel, CLT can stay structurally stable even when subjected to high temperatures. If exposed to fire, the outer layer of timber chars and forms a layer around the structural core, protecting it and helping it keep its load-bearing capacity.
We leave with a video and a question: given what you have just read if given the chance, would you live in a wooden skyscraper?