Innovation - Spring 2024

The evolution of BC wood building height limits, 2009-2024

But some experts aren’t so sure that BC should be rushing to build up. “BC is moving in an accelerated growth—beyond any other province in Canada—to the adoption of mass timber,” said Kieran Ager, P. Eng., a fire engineer and branch manager at the building code consultancy LDMG. “It’s forward thinking, but also exposes a lot of risk.” Raising the bar on fire safety Fire safety is one of the most prominent hazards. “We need to consider that timber itself is combustible,” said Dr. Felix Wiesner, a UBC Forestry professor who specializes in fire safety engineering. One time-tested way to address combustibility is through letting the surface of the wood char, creating a black layer of non-combustible carbon. That was what happened when, during a 2023 National Research Council experiment, a team of researchers set fire to five, full-scale building models to see how they would perform in a real-life scenario with no sprinklers and no firefighting interventions. Both EMTC buildings and light wood frames were tested during the experiment. Even without intervention, the buildings remained structurally sound. Both the traditional wood framed buildings and the EMTC buildings in the test self-extinguished after about four hours. However, during all of the tests, “deep-seated hot spots and smoldering” persisted for hours and required extinguishing assistance from the fire department. Embers buried beneath charred surfaces are common in burning buildings. “If that

2020: Mass timber-specific regulation introduced

2009 BCBC

Pre-2009

2018 BCBC

2024 BCBC

smoldering continues, and you don’t check for it, it can either reignite the fire at some point or you get structural collapse eventually,” said Wiesner. In a real-life situation, those faced with a house fire usually rely on infrastructure such as the fire

department and sprinkler systems to prevent serious damage. “Sprinklers are an effective means of controlling fires,” said Ager. “And we can rely on the fire department to put out fires. That infrastructure is all part of the picture.”

Innovation Spring 2024

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