Mass timber construction as opposed to light-frame wood construction, is a category of engineered timber products made of large, solid wood panels, columns or beams. These elements are utilised for load-bearing wall, floor and roof construction. Mass timber building components are almost always prefabricated off-site, and are formed through lamination of raw lumber and connected using mechanical fasteners or adhesives. Using mass timber can provide an environmentally friendly substitute for carbon-intensive materials and building systems such as steel, aluminium and concrete.
Cross-laminated timber (CLT) is a large-format engineered wood panel, made from layers of solid sawn lumber. Each lamella of boards is typically oriented with the wood grain perpendicular to the adjacent layer, to provide a geometrically stable and structurally rigid sheet. A CLT plate consists of an odd number of lamella, typically three, five or seven layers.
CLT is well suited to wall, roof and floor structures.
Glue-laminated timber (GLT), or Glulam, consists of lumber laminated in the same direction, to make a building component. Having the timber gain oriented the same way provides direction-specific structural performance, also referred to as anisotropic materialbehaviour.
GLT is typically utilised in beams, columns and posts, header structures and trusses.
The life of a mass timber project starts with the careful selection of raw material in sustainable forests and culminates in the rapid assembly of precise building components on site.
Wood is a natural, renewable material for building. Kilogram for kilogram, timber has a lower environmental impact than concrete or steel. The use of mass timber products can play a significant role in reducing the carbon footprint of a project, achieving eco-friendly design goals or even net-zero carbon construction.
A key sustainability attribute of mass timber construction is carbon sequestration and storage. During the life of a tree, atmospheric carbon dioxide is removed from the air, is converted through photosynthesis and trapped. Harvesting a tree and processing the wood into a mass timber building then holds this captured CO2 for the lifespan of the building.