The magic of Cross Laminated Timber
Cross Laminated Timber (CLT) is being hailed as the engineered wood of the future and is becoming common in sustainable design and construction around the world. So what’s all the fuss about?
Described as “jumbo plywood”, CLT is composed of layers of timber – aka lamellas – glued together with the grain alternating at 90-degree angles for each layer.
Cross-laminating wood enhances its structural properties by distributing the along-the-grain strength of wood in both directions. As a result, CLT panels can be used as flooring, walls and roofs.
A highly-awarded Australian project that employed CLT is International House Sydney, the country’s first commercial engineered timber building. Designed by Tzannes architects, it is a spruce CLT and Glulam structure, including floors, columns, walls, roof, lift shaft and stairs, supplemented with recycled Australian hardwood.
CLT is a timber panel product that has similar characteristics to a pre-cast concrete panel. One of the advantages of CLT is that it’s far lighter than concrete, making construction simple and efficient. Take, for example, Canada’s Brock Commons Tallwood House by Acton Ostry Architects – the wood structure of which was completed at the rate of two floors a week, approximately four months faster than conventional construction methods.
In November 2018, 25 King (the tallest timber structure in Australia to-date) was completed by Lendlease. Designed by architecture and interiors firm Bates Smart, this Brisbane project combines Glulam (glued laminated timber) and CLT (cross laminated timber).
The sustainable aspects of CLT are among its greatest attributes. In the case of 25 King, its engineered timber structure was substituted for concrete or steel, and consequently has a significantly lower carbon footprint, in effect acting as a carbon sink. When compared with conventional building materials, CLT is a greener alternative.
CLT has come a long way since it was first developed in Switzerland in the 1970s. Its potential as a construction material is continually being explored through an ever-growing list of projects being built across the globe.