The manufacturing of cross-laminated timber (CLT) for the construction industry uses standard dimension lumber and adhesives to create solid, monolithic timber panels of varying thicknesses. At Element5, we use SPF lumber to create CLT “billets” that can be as large as 16m long by 3.5m wide. It is from these raw billets that we cut out the individual structural components of a building including floors, roofs, walls, stairwells and elevator cores.
We use CNC machines to achieve any cut that we need to for a given design. At a minimum, we trim the four raw edges of the billet square. If the full-sized panel is not needed in a building, we cut out the smaller panels based on how they have been optimally nested in the billet, and then execute any details the engineering department has incorporated into the design. These detailed cuts include pre-drilled holes and slots for connections, as well as window and door cut-outs, and openings for mechanical, electrical, and plumbing services.
This form of off-site manufacturing is valued because it brings improved efficiency to the construction process, both in terms of human resources and material resources. But as efficient as CLT manufacturing is, that doesn’t mean it is a waste-free process. Fortunately, wood ‘waste’ is desirable and can be easily streamed into secondary uses.
The sawdust we generate, for example, is collected by a waste management company and repurposed as animal bedding. This particular outcome is possible because the adhesives we use do not emit VOCs. Naturally, the intended beneficiaries of this clean technology are the human occupants of our buildings, but this high standard also means our wood waste is entirely safe for animals, too.
Manufacturing waste in the form of chips and sawdust is diverted from landfill and used as animal bedding.
Another interesting by-product of our process is the ‘off-cuts’ that are removed from the panels when we create window and door openings. These relatively large blocks of solid wood are being transformed into furniture, stairs, and other feature elements and are often incorporated into the mass timber buildings that they’ve been cut from. This effort adds value, reduces waste, and helps realize the greatest possible benefit from each panel we press.
This resourceful, sustainable practice of maximizing downstream value, combined with clean manufacturing technologies and responsibly sourced lumber inputs, results in low carbon buildings and products that optimize the use of our forest resources.
CLT off-cuts repurposed as window frames, floating shelves, stairs and a workbench. Photos courtesy of MCH https://www.mchqc.ca/