What is CLT wood? CLT is a sustainable building material.

The construction industry consumes vast amounts of concrete, steel from smelted iron ore, and stone, and it is gradually running out of resources. The construction industry is one of the world's largest sources of solid waste. Bill Gates once unexpectedly posted a comparison chart of cement consumption between China and the US on his personal blog. The chart showed that between 2011 and 2013, China consumed 6.6 billion tons of cement, exceeding the total consumption of the United States throughout the entire 20th century.

But how can we change this if most of the building materials we use are non-renewable?

Cross-laminated timber (CLT) is a new type of engineered wood material that originated in Europe and has gained widespread popularity and attention in other parts of the world over the past decade. It stands out for its strength comparable to concrete, its beautiful and natural appearance, versatility, ease of assembly, and sustainability.

Image ©Photolux Studio

CLT (Continuous Laminate) is composed of sawn, glued, and layered sized timber, with each layer laid perpendicular to the adjacent layer. By gluing the timber at a perpendicular angle, CLT boards achieve the same structural stiffness in both directions. Therefore, the panels exhibit excellent tensile and compressive strength.

CLT (Glulam) is a sustainable material because wood is the world's only renewable building material and its production does not require the burning of fossil fuels. Dimension lumber and glued laminated timber (CLT) products have been widely used in a wide range of large-scale construction projects, from stadiums to bridges to residences. Due to its natural appearance and structural strength, it has become an ideal material for building skyscrapers.

Photo: Construction site of the 18th floor student residence at UBC

CLT can be easily CNC machined in the factory, with drilling and metal connector installation pre-drilled according to the BIM design. On-site construction is like building with Lego bricks, achieving an assembly rate of over 90%. Furthermore, because CLT is a heavy-duty engineered wood material, the timber can be exposed within the permitted floor height according to fire safety regulations, significantly reducing interior finishing procedures. CLT project sites generally generate almost no construction waste.

Although the production cost of CLT materials remains high, they are still an excellent alternative to concrete steel when considering factors such as shorter construction time, better quality, and environmental friendliness.