Published 2 February 2015 by Stora Enso
Stora Enso’s reputation dates back to 13th-century Sweden. Today, Stora Enso has leveraged its success by no longer solely focusing on the traditional pulp and paper industry but transforming itself into a value-creating renewable materials company focusing on growth markets.
One of the growth segments is cross-laminated timber (CLT), which stays true to Stora Enso’s focus on building with solid wood. This breakthrough material has picked up a series of industry accolades in Austria, Finland, the UK and Slovenia, among others.
CLT is made in Stora Enso units in Austria by layering solid-wood panels crosswise. CLT is just one fifth of the weight of concrete, is very strong and is delivered as large-scale single components. Because CLT is factory-made and delivered for assembly, there is no waste at the building site and construction time is significantly shortened. The product has been thoroughly tested; experts say CLT is fire-safe and medium-rise buildings made out of it can withstand earthquakes.
CLT is also certified and the wood is sustainably sourced. Moreover, one cubic metre of CLT holds one tonne of carbon dioxide.
Q&A with Jari Suominen
Jari Suominen is the Head of Building and Living at Stora Enso.
What are the main advantages of using CLT to build houses?
The inhabitants of a CLT house get the advantages of a pleasant indoor climate. Wood is able to absorb moisture from the air which it then releases when the air becomes drier. In addition, wood creates an enjoyable acoustic environment that also meets demanding sound insulation requirements. CLT is a carefully prefabricated building material, so it can cut construction time by up to 50 per cent compared to other building materials. It is also strong: though lighter than concrete, it has enormous load-bearing capacity. CLT also works well in areas that are prone to earthquakes, as wood is flexible and so better able to withstand tremors.
What are the main challenges when using wood as a primary construction material?
Instead of calling them challenges, I would like to revise certain preconceptions. For example, solid wood is far more fire-resistant than usually assumed. Large pieces of wood do not burn but char; in addition, the carbonised surface protects the internal CLT layers so that the construction does not collapse. As is the case with any material, good construction means good durability. You can improve the longevity of wood by keeping the structure dry and providing protection. Wood is the world’s oldest and yet most modern building material.
Where are CLT’s biggest markets?
CLT has its roots in central Europe – Austria, Germany and northern Italy are strong. Growing markets in Europe include the UK, France and northern Europe. Interest is also increasing in markets such as Japan, Australia and North America.