Red pine has historically been overlooked as a lumber source for homes and other buildings, but recent testing shows it can cost-effectively be engineered into structural cross-laminated timber (CLT) panels for housing.
The testing was done by the Mass Timber Institute (MTI) in collaboration with the Ontario Woodlot Association, Limerick Forest and Canadian homebuilder CABN. The MTI is based at the John H. Daniels Faculty of Architecture, Landscape and Design at the University of Toronto.
According to Jackson Wyatt, CEO and founder of CABN, the lamination process of CLT allows for a wide scope of materials for its composition, including red pine, which is less expensive than traditional wood materials used in CLT.
What’s more, there are about 280,000 hectares of red pine trees in Ontario, representing an untapped potential to scale green, prefabricated construction, he says.
That supply opens up economic opportunities for Canadian sawmills. And it offers harvesting opportunities in municipally-owned forests and on crown-owned land, he says.
“When we can translate those alternate (red pine and other underutilized trees such as poplar) species we can build all the homes that we need in Canada.”
CABN began four years ago as a homebuilder of prefabricated net-zero housing and today offers high performance proprietary building shells that include structural panels.
Historically, red pine has been used for hydro poles but to get the tallest and straightest timber stands the forests have to be thinned of smaller, less desirable trees, which have at times been turned to compost.
“Ultimately when you can scan and process different grades, sizes and varieties of species of lumber (for mass timber) it reduces the costs,” he adds.
Wyatt says lumber grading standards haven’t changed much over the past 50 or so years.
“What we are endeavouring to do with this mass timber approach is have a wider variety, scope (of tree types) for its composition because when it (CLT) is processed it is a very strong, robust final element.”
CABN started doing research on red pine’s use in CLT about two years ago.
“It was all about kick-starting investigations to get a wider range of natural resources available for construction.”
Wyatt says the company works with sawmills to use Canadian natural resources for its building products, primarily targeting Canadian markets.
CLT is shipped to CABN’s 93,000-squar- foot factory in Brockville where insulation, membranes, strapping and sometimes windows are added to create prefabricated panels for home assembly.
The company has the capacity to do 300 2,000-square-foot homes annually, he says, noting its mission is “to build rapid, sustainable housing affordably.”
Building costs are on a par with conventional stick frame construction but Wyatt says through prefabrication a 2,000-square-foot home can be erected in seven days and finished over the next five weeks, cutting months off stick-frame home building times.
While Wyatt is optimistic of the shift to red pine and other tree species sourced for CLT he admits it won’t happen overnight.
“One thing you can’t speed up is the proper accountability and certification.
“By elevating our quality assurance and scanning at CABN…it allows for the industry to move quickly in accepting these innovative new products. But it always takes a little bit longer than you expect.”
