Pine beetles kill forests, builders seek to use the wood
Posted: January 6, 2013Source: Pique
You can’t miss it because the devastation runs as far as the eye can see. Driving between Merritt and Kelowna on Highway 97C in British Columbia’s southern interior, it is possible to feel a kind of terrible awe while passing mile after mile of rusty-coloured, dead pineforests.
It is the work of one small insect amplified billions of times into a catastrophic infestation, a man made situation and one of Canada’s most graphic indicators of climate change, thanks to hot, dry summers and mild winters. The mountain pine beetle creates these enormous swathes of dead forest when the insects burrow into bark and outer layers of the trees, killing them.
Such forests can be found all over the province and now into Alberta and in several U.S. states.
Just this week, the scale of pine beetle outbreak was said to play a part in shaping climate change, according to University of Toronto scientists in a paper published in the journal Nature Geoscience.
But along with the environmental impact there is an economic one. For roughly the last 21 years, since the outbreak was identified, B.C.’s forestry-driven economy has suffered from the fallout of what to do with beetle-kill wood.
Pine wood is dyed a kind of grey-blue and is softened when the beetles attack it. Only five years ago, industry believed little could be done with it apart from artistic or cosmetic uses for wood, which was being marketed as “denim pine.” Traditional uses of pine, in construction and elsewhere, were considered impossible for beetle-kill wood.
Yet, the millions of impacted trees needed quick harvesting to avoid them rotting away in the wilderness and emitting CO2 gas.
In the last three years, technology has begun to find a way.
Alpine Timberframe and Design, a Brackendale company known for its custom residential and commercial work in wood, was brought in in 2011 to work on an innovative construction project at the University of British Columbia which incorporates beetle-kill wood for more than cosmetic reasons.
UBC’s Bioenergy Research and Demonstration Facility, the building in question, was named this year as one of the world’s top 100 most innovative and inspiring projects in KPMG’s Infrastructure 100 listing. It is North America’s first biomass fuelled, commercial-scale heat and power system, designed on a scale to produce energy for a small city. It opened in the spring of 2012.
The key, in terms of making beetle-kill wood usable on this scale, said Alpine Timberframe’s president Richard Lutz, is cross laminated timber (CLT).
Cross laminated timber is a versatile multi-layered panel made of lumber, with layering of board cross-wise to increase rigidity and strength, similar to plywood. CLT is used as long wood spans and massive slabs, making it suitable for major construction projects.
It was developed in Austria and used in passive house technology, as well as the U.K.’s Murray Grove Building, the tallest wood structure in the world. Slabs used in Europe can be up to 24 metres long, but smaller wood presses in Canada means panels are on a smaller scale, around 7 metres long.
It is in these slabs that beetle-kill wood is integrated, slabs that are strong enough to replace concrete. Beetle-kill wood has been used throughout the interior of the bioenergy building, which is located on UBC’s main Vancouver campus.
“The beetle wood is being used more and more… it depends on the structural requirements. In this particular project it was really only CLT panels that were MPB (mountain pine beetle) wood and the timber posts and beams were Douglas fir,” Lutz said.
Brent Sauder, the director of strategic partnerships at UBC, said the bioenergy facility is part of the university’s commitment to cutting greenhouse gases by 33 per cent by 2015.
“The intent was to use the building as a first North American demonstration of cross laminated timber,” Sauder said, adding that the building was the first commercial use of CLT wood manufactured in Canada. Before this, CLT was only available if imported from Europe and did not use beetle-kill wood.
The B.C. Ministry of Forests and Canadian Wood Council contributed to the cost of the project because of this use of denim wood, and the federal forest products innovations research group FP Innovations in Vancouver and Pointe-Claire, Quebec, was also involved, he said.
“The technology behind this is very new… when we started construction two years ago we were really at the leading edge,” Sauder said.
Lutz believes that beetle-kill wood, which sells for deflated prices because of the amount of beetle-kill timber now on the market, means that CLT panels can be cheaper, opening its use up to other opportunities including in residential construction. Other bonuses, he added, are its ability to withstand earthquakes and absorb sound.
“I think the part that is really missing (from studies into the viability of CLT panels) is how they can be used in residential construction for much more energy efficient homes and to meet the new building codes for seismic activity,” Lutz said.
“It is absolutely so strong. They did a study on Canadian CLT panels in Japan and they built a building and put it on the world’s largest shake table.” The building was shaken and measured for shifting nine times, which has never happened, he added.
Lutz is due to work on a second project using beetle-kill CLT panels at UBC, on the new student union building. His work on the project starts in April 2013.
While CLT is making waves on one Lower Mainland campus, it is the Okanagan College in Penticton that can claim the prize of first using pine-beetle kill wood as a stand-in for Forestry Stewardship Council-certified wood.
The Centre of Excellence in Sustainable Building Technologies and Renewable Energy Conservation, which opened in 2010, used pine beetle-kill wood for framing the building.
Building on the “ground zero” of the pine beetle outbreak, it was essential to find a way to use the wood in construction said Tim McLennan, the director of Kelowna operations with CEI Architecture. He said the pine-beetle wood holds the same quality as other woods if harvested quickly, and using it has supported forestry communities hit hard by the infestation.
The issue was meeting FSC standards with pine-beetle wood, which is clear cut, and that is a no-no, McLennan said. This meant negotiating with the International Living Building Institute, which accepted the wood as sustainable for the first time.
“The Okanagan is the most affected zone, basically. It’s near and dear to our hearts here as a major socio-economic issue,” McLennan said. “Using this wood is possible given what we’ve learned about it in the last few years. A lot of the framing and lumber now integrates pine-beetle lumber.”