Six years after the launch of the concept, project partners Dialog and EllisDon could be just a year or so from hitting the market with their new Hybrid Timber Floor System.
Using a prototype composite of post-tensioned concrete, cross-laminated timber, rebar and an engineered coating, the invention with its 40-foot panels would allow mass timber–based floor systems to be used in non-residential long-span construction such as office and institutional, sectors that until now have been limited to traditional building materials.
Dialog, an architectural firm, and EllisDon hosted a project update event at the University of Toronto on Jan. 24 in collaboration with WoodWorks and the Mass Timber Institute. The event was billed as Hybrid Timber – Low Carbon and Long Spans.
Craig Applegath, founding partner of Dialog, said in an interview that most projects involving prototypes have setbacks but the hybrid timber project has instead had one exciting discovery after another.
“If you had to measure the journey from start to finish, we’re 90 per cent of the way there,” said Applegath.
Once final testing has been completed, expected in about a year, “Then it is a product that is worthwhile going out to market.”
“I think a year from now, we’re talking to various clients that are interested. Maybe it will be going on a building a year-and-a-half from now.”
To capture the attention of owners, designers and engineers, the partners created the floor plate for prototypical use in a 105-storey office building.
On Jan. 10, 2018, EllisDon posed the challenge: “How can we design a mixed-use highrise building using wood, steel, concrete and other advanced materials that maximizes the overall use of sustainably harvested wood by volume in highrise construction in the most cost-efficient, energy-efficient, low-carbon and elegant manner, that is also conducive to human well-being, and the well-being of the environment?”
The floor system was targeted because that represents 70 per cent of the materials in a building.
“We’re in deep trouble,” Applegath said of the climate crisis. “And what can architects and engineers do? One thing they can do is build with sustainably harvested wood.”
In 2022, the federal government announced a contribution of $550,000 through the Green Construction through Wood and the Investments in Forest Industry Transformation programs.
Product testing has primarily been done at the FPInnovations lab in British Columbia. Among the final tests to be done in the next year will be analysis to test creep and bending, and also more fire testing.
“We’ve talked to developers across North America before the pandemic. These were all commercial developers, commercial office space and they said, ‘as soon as you’ve tested and confirmed that it meets all the code as well as physics and engineering requirements,’” said Applegath.
The market has changed in the half decade since the project was launched and now the office sector is slow.
Applegath said the pitch has changed somewhat and the partners are now talking up the product as also suitable for institutional clients such as hospitals, colleges and universities. Atriums and industrial settings were also mentioned during the presentation.
EllisDon analysis has confirmed that the product incorporates about 14 per cent less carbon usage than concrete beam slab, 25 per cent less carbon than precast concrete hollowcore and 38 per cent less carbon than composite steel/concrete deck.
Insurance costs are significantly higher for the hybrid project and with those folded in, the hybrid system costs about five per cent more.
But given the hybrid timber floor plates are thinner by about 10 per cent, that’s a potential premium that has not been factored into costs.
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