What Mass Timber product is up to 60-feet long, 14-inches thick and 12 or more feet wide and is made of 99.99 per cent wood? That’s right – no metal fasteners and the only glue is in the finger jointed material that makes up the wood panel.
The answer is a dowel-laminated timber (DLT) wood panel, which is similar to other mass timber wood panels like cross-laminated timber (CLT), which uses a lot of glue, and nail-laminated timber (NLT), which uses a lot of nails.
As Paul Macdonald points out in the March /April issue of the Logging and Sawmilling Journal, mass timber products are one of the most in-demand construction materials these days.
All three panels are challenging concrete and steel in the construction of larger commercial buildings. These prefabricated solid-wood panels are lighter and prefinished, making construction easier and faster, along with simpler foundations, making this technology greener and more cost effective.
A new 50,000 square-foot value-added plant in Abbotsford should help our dwindling timber supply by using a lot of previously undervalued timber.
Structure Craft Builders Inc. is owned and operated by the Epp family, which obtained most of the plant equipment from Europe, where production and markets are well established. Their new plant is the first in Canada.
DLT construction is described as follows: laminations of milled finger-joined dimensional lumber are friction-fit to each other, on edge, using a series of three-quarter-inch hardwood dowels, that are hydraulically pressed into pre-drilled holes. The lumber used as raw material is generally undervalued wood and includes beetle-affected wood, but virtually any species can be used including Douglas fir, Hemlock or Cedar.
No mention was specifically made of using wildfire salvaged wood, but I assume it should also be possible as long as the quality is close to other marginal quality lumber.
The company’s finger jointer, moulder and DLT are able to use a variety of material, including two- to six-inch material, depending on the desired product. The new plant is also able to produce panels up to 60-foot long, compared to the 40-foot panels in Europe.
One big advantage of DLT is a faster production time over CLT, because there is no glue or press curing time. The fully automated process can produce a panel every five to 10 minutes, depending on the size.
Architects are promoting the use of solid-wood panels for greener carbon sequestration features, as well as prefinished interior walls, which eliminates the need for using the traditional dry wall or equivalent construction methods. These panels should also be exempt from the USA trade restrictions.
Many in the industry have confidence that mass timber will have a place in the commercial building trade, with a good example being the tallest project so far, which is in Canada. The Brock Commons Tallwood building (the student residence building at the University of British Columbia) is 18 storeys high and boasts the sequestration of 1,753 metric tons of carbon, and only took 66 days to construct in 2017. This building was constructed from CLT panels and glu-lam plus pillars from the Structure Lam plant in Okanagan Falls.
Jim Hilton is a professional agrologist and forester who has lived and worked in the Cariboo-Chilcotin for the past 40 years. Now retired, Hilton still volunteers his skills with local community forests organizations.