With changes to the Ontario Building Code starting in January there’s been some traction in the mid-rise wood structure sector.
Now that wood framed buildings can rise to six storeys, several owners have opted to go that route, citing speed of construction and cost as their prime motivators.
While there’s not a stampede away from masonry or even steel, there is a shift and that will in turn mean there’s a need for carpenters who are trained in how to handle the materials integrated into the timber structures.
To that end, Ontario’s Carpenters’ union launched a mid-rise training program for their members last January and have been integrating it into their second and third year apprenticeship program.
Working with stick lumber for residential is different than the knowledge required when working with engineered wood products at six storeys.
Each level of the structure requires some slightly different materials such as I-joists and Laminated Veneer Lumber (LVL).
"Ironically, the limit on wood structures’ height actually goes back to when the code was first written and fire department hoses couldn’t go above three storeys on the ladder," says Tony Currie, the training centre coordinator at the Rowntree Dairy Road facility. "It was a throwback."
The training program in place now is also offered to journeymen carpenters to add to their repertoire and features a 33-foot high mock up of typical engineered wood and nominal lumber in a structure, with connectors, stairs and even a wood framed elevator shaft.
"The code requires stairs and elevator shafts to be non-combustible," says Currie.
"But that doesn’t mean it has to be masonry or steel. Out in British Columbia they are using wood to frame elevator shafts and then putting drywall over the top. It won’t burn. You can take a blow torch to it and it won’t ignite."
The union reached out to the leading authorities in Ontario on mid-ride design and construction and brought in David Moses of Moses Structural Engineers and Quadrangle architects’ Marco VanderMaas.
They’ve also had British Columbia architect Jim Taggart come to lecture about wood as a material in mid-rises. Taggart teaches history and theory in the architectural science degree program at the British Columbia Institute of Technology (BCIT), and is editor of Sustainable Architecture and Building magazine (SABMag).
"They also come back and lecture to our apprentices about working with mid-rise structures."
Having that expertise at hand and getting them to communicate directly with the members who will be on the front line building these structures is a huge boost, says Cristina Selva, Carpenters’ Local 27 Training Centre executive director.
"It’s a challenge to design a curriculum because there’s so little room for variance," she says. "And the code only gets updated every 10 to 12 years."
Having the mock up model, she says, allows the apprentices to visualize what they’re being taught in theory.
The mid-rise model takes up a wall at one of two training centres on Rowntree Dairy Road in Vaughan. The room is also filled with work benches, power tools and areas where apprentices learn to build entire residential homes, though in smaller scale, making the roof trusses, walls and framing openings only to tear it all down on the last day of their classes.
"The point is that you can’t just use the same techniques as you would for residential framing working with mid-rise lumber," says Currie.
"So this is just in time training in some ways."
It is early days yet for wood mid-rise construction in Ontario. However, proponents believe the future is bright and that taller structures will be approved through changes to the code as the licensing and inspection authorities start to understand the limitations and the pluses of working with timber.