World's tallest timber tower topped off
It seems like only yesterday that Acton Ostry's wood tower for the University of British Columbia was a controversial rendering. Now the structure is complete, topped off, eighteen floors of glue-laminated wood columns supporting cross-laminated timber floors. It went up really fast (just 66 days) and in fact is ahead of schedule; according to UBC:
John Metras, the managing director of UBC Infrastructure, confirmed the building is ahead of schedule. The last wood panel – called a cross laminated timber floor panel — was installed on August 9 and the last glue laminated column was installed on August 12 — ahead of schedule. "Construction just went really smoothly," explained Metras. "It was well designed and the construction sequence went smoothly."
Most of the concerns about the building relate to fire safety; as we noted in our earlier post, the building is fully sprinklered, the wood is encapsulated in concrete and drywall with a two hour fire rating, and the stairs are poured concrete. However Russel Acton also points out inherent properties of wood:
"Have you been up through forest fire country after a forest fire has been through? So you see all these trees? They’re standing and haven't fallen down," said Acton. He explained that fire will burn through the first layers of wood and then stop. "The reason why it stops is that in the depth of that charcoal layer, oxygen can’t get into the wood to keep the combustion process going."
© Timber tower under construction
There are also real advantages to wood construction in earthquake zones; according to Wood Skyscrapers, "In the event of an earthquake the timber structural weighs less than the concrete alternative and provides better energy dissipation, allowing it to exemplify superior seismic performance."
And of course TreeHugger loves it because wood is a renewable resource, and building with it sequesters carbon dioxide. In this building, according to Hermann Kaufmann, "the carbon stored in the mass timber structure, plus avoided greenhouse gas emissions, results in a total estimated carbon benefit of 2,563 tonnes of CO2, which is equivalent to taking 490 cars off the road for a year." The wood used here, supplied by Structurlam, is locally harvested and manufactured just up the road in Penticton.
It's a shame about all that fire protection, the exposed wood is really beautiful. The view is pretty terrific too. The building is supposed to be complete by the start of the fall 2017 school term but looks like it might be ready by next spring. Here's the last panel being lifted and installed: