The use of cross laminated timber (CLT) in medium rise applications is becoming increasingly prominent across the global built environment. This innovative and sustainable product has presented fierce competition to the steel and concrete industries, delivering a structurally sound, alternative solution to buildings up to 10 storeys high, with a capacity beyond this – penetrating markets that previous timber structures have not been able to touch.
CLT is a structural two-way spanning timber panel that can be used to form walls, roof and floor panels as well as shear walls. It is produced by laminating and finger jointing soft wood timber lamellas at 90° to the layer below, this commonly encompasses between three and seven layers. The build-up uses a formaldehyde free adhesive between each layer to deliver a safe and environmentally sound solution. Due to the nature of CLT construction, movement of the timber panels is dramatically reduced. Longitudinal and transverse movement is restricted to 0.01% and 0.025% per percentage change in moisture content respectively. The lightweight nature of the material allows foundations to be reduced – saving costs. CLT is extremely clean to use, generates very little waste and is constructed from readily available, renewable softwoods. This makes high BREEAM ratings more achievable.
CLT has been around for a number of years and has been applied largely to the education market, however, is now also being utilised in residential buildings. The ongoing housing crisis, coupled with the brick and block shortage – both results of the economic downturn – has generated a demand for an alternative material that is able to be manufactured on mass in a short timescale. These factors, together with its sustainable credentials, have contributed to the rise of CLT and we are now seeing more buildings constructed from this engineered timber solution appearing across our global skyline. By building up, housebuilders are able to create more homes on a smaller surface area, offering a faster return on investment without spending an excessive amount on land.
In terms of commercial building, steel may offer some competition to CLT as it has previously dominated this market, however, now we are seeing more hybrid structures that incorporate both steel and CLT, bringing together the benefits of large spans achievable through the use of steel and the environmental credentials that come from the application of CLT. While smaller commercial buildings are suited for pure CLT construction, it is becoming more apparent that hybrid timber structures are making their mark in the commercial market for much larger buildings.
The transition towards CLT is not something that will happen overnight, however, the benefits that the material provides are unique and something that the industry is crying out for. This is a material that delivers unparalleled sustainability and availability, solid practical and commercial advantages - including swift erection - all without compromising on quality. I believe that this is only the beginning of the rise of CLT. As we continue to address the problems subsequent to the recession, the application of this structurally strong, sustainable material will continue to grow.
Original Link - Xlam Alliance
