Wood is arguably the greenest building material, and wow, there is a whole log of arguing about it from the concrete and steel industries. But the Province of Québec is covered in trees, and now has factories that can produce Cross-Laminated Timber (CLT) a sort of plywood on steroids that is solid, strong and yes, fire resistant. Until recently builders could only go to six storeys (That’s how they spell it in Canada, no comments please) using conventional stick framing.
Now the Quebec authorities recognize that CLT, or massive timber, is a different material with different properties, so they have approved it for the greater height. (Got French? Read Bâtiments de construction massive en bois d’au plus 12 étages) According to FP Innovations, a wood promotion organization:
Research in Canada and internationally has shown that it is possible to construct safe and secure wooden buildings greater than 6 storeys in height and that, at those heights, rather than light wood framing, mass timber construction materials must be used such as cross-laminated timber. The Government of Québec is following in the footsteps of countries in Europe, where similar wood-based construction methods are permitted. Québec has recently seen an increase in wooden construction with a local consortium announcing the development of a 13-storey wooden residential building in Québec City.
Here’s that building, covered on TreeHugger earlier.
Of course the concrete industry is outraged, claiming that the decision will compromise public safety, noting in a press release:
Like the rest of Canada, Quebec has little experience in the construction of six-storey wood buildings – how can we venture into the construction of even taller wood buildings? The government has a duty to protect the health of its citizens, not that of a particular industry.
This ignores the fact that CLT construction is a very different thing from stick framing to six storeys, and that there is a lot of European experience to refer to, and a lot of fire testing. As the table shows, any building between 7 and 12 storeys needs to be massive wood, have a two hour fire rating, identical to steel and concrete, and be equipped with sprinklers.
And if the government of Quebec “has a duty to protect the health of its citizens”, permitting construction using materials that have a negative carbon footprint is a lot better than depending on concrete, responsible for 5% of the CO2 generated every year.
The steel industry isn’t too thrilled either, according to the Canadian Press:
Hellen Christodoulou, Quebec regional director of Canadian Institute of Steel Construction, added that not enough research has been completed to ensure the safety of taller wooden buildings. “The government as not studied this well. It’s just a political move and it’s problematic,” she said in an interview.
The facts remain that there has been a lot of research on cross-laminated timber, that wood is a renewable resource that is as local as it gets in Quebec, that it sequesters carbon whereas concrete makes tons of it. No wonder the concrete people are antsy about it. And let’s hope Ontario and the rest of Canada follows in Quebec’s footsteps soon.