By Peter Burrows It ain’t easy, making something new at minus-40. In fact, it’s sometimes downright impossible. We talk to some of the experts in cold climate construction to see what’s new in the field and discover some of the tips that make it all possible.
My cheeks start to burn from the cold and my fingers are losing dexterity, and I’ve only been outside for five minutes. I have on my long johns, jeans, insulated pants and boots, parka, fur gloves and hat, and neck warmer. Still, the chill wind is pouring in through every crack. I’ve dropped by one of Clark Builders’ Yellowknife projects – the new data centre for the NWT government, which is not yet closed in – with my photographer to get a few shots. As we’re standing there shivering – I can’t believe camera equipment works in these conditions – along comes René Baumgarten, ice growing on his beard, laughing and joking with a co-worker.
“At what temperature do they allow you guys to quit and go inside?” I ask.
“Oh, I dunno,” says Baumgarten, his construction helmet jammed between a fur hat and the hood of his sweater. “It’s a nice day, only minus-42, and there isn’t much of a breeze.”
In some ways, winter is the best time to build: People need work and are more available, and usually bid prices are lower.
But I don’t know how they do it, working outside through an Arctic winter. Sure, the breaks come a little more frequently and last a little longer, but still, they’re out there most of the day, exposed to the unforgiving elements.
And it’s not just the humans that suffer. The gear freezes up, engines struggle to keep warm, and cement refuses to pour. But ingenuity knows no bounds. Through trial and error, force of will and sheer bravado, people have long been perfecting the art and science of building in (and for) Arctic conditions.
The need forNorthern know-how
Of course cold-climate construction isn’t just about building when it’s cold out, it’s about building for extremely cold weather. A lot of the problems arise when the extremes of Arctic conditions are not taken into account in the planning stages. “People come up from the south and build houses the way that they know how to build houses,” says Ty Keltner of Alaska’s Cold Climate Housing Research Center, an industry-based non-profit created to facilitate better, and more cost-effective, building for those living in circumpolar regions around the world. “Those houses are not fit for extreme cold temperatures,” says Keltner. “From thin walls without enough insulation to improper drainage – people don’t know how to build in an area that will freeze and thaw in the winter and still have it drain properly.”
The CCHRC tests products and techniques, trying to determine which materials work in extremely cold temperatures, how to deal with wind-driven snow, and how to make a building appropriately airtight. “You want your home to be as tight as possible so the heat doesn’t escape,” says Keltner, “but at the same time you don’t want it to be so tight that it drives up the moisture and causes mold problems.”
The CCHRC also does some design and consulting work to help people build better. One project they’ve spent a lot of time on is the remote wall, which puts insulation on the outside of the house and moves the vapour barrier from the inside to the outside of wall. “On top of the vapour barrier we put layers of foam. That prevents moisture outside from getting into the structure of the building,” says Keltner. “At the same time, any moisture you have inside your building from cooking and bathing and stuff like that, should dry out if it gets into your walls because you have so much foam insulation on the outside.” This method moves the dew point outside the vapour barrier and keeps the wooden frame dry.
Other projects keeping the CCHRC busy include a pilot program using ground source heat pumps, and, more ambitiously, a venture to build an energy-effecient Arctic dream home for a mere $150,000.
Industrializing the process
Dr. Mohamed al-Hussein, an engineer at the University of Alberta’s Hole School of Construction Engineering, has a slightly different approach. He thinks the best way to build in winter is to do as much of the work as you can inside, at a factory. “We still build the same way we did hundreds of years ago,” he says. “We did not move ahead the way the automobile industry did, which is miles away from where it was even 10 or 15 years ago.”
Dr. Hussein’s approach is what some people call modularization, but he calls “the industrialization of the construction process through fabrication of modular and panelized systems.” He works on both modular assembly and pre-cast concrete construction. He is moving away from stick-frame, onsite construction to a factory-based model. “There are lots of advantages,” he says, “and one of them is the cold.” He’s worked on everything from pre-cast cement basement walls (“It can take just a few hours to put them in place,” he says) to pre-cast sidewalks and brick-clad walls, and now he’s on to driveways. “If a homebuilder gives you the key to the house in October, you won’t have a driveway until mid-summer because they can’t put the concrete on frozen ground,” he says. “Builders asked me if we could do this in a pre-cast system, so that’s my next project.”
Building The Frozen Roads
One of the biggest construction projects – OK, it’s not a single project, but for our purposes, we’re treating it as one – every year in the North is the building of the thousands of kilometres of ice roads that serve outlying communities and the diamond mining activities north of Yellowknife. Building and driving on ice roads may not be as risky as portrayed in Ice Road Truckers, but it’s still a job you want to be careful with. “Many people think of just one parameter: What’s the ice thickness?” says Sam Proskin, an engineer with EBA Engineering Consultants who has worked on the Tibbitt to Contwoyto winter road since 2001. “If it’s 50 centimetres or 100 centimetres then we’re good to go. In many cases that is an acceptable way to do it, as long as you have someone knowledgeable making those ice measurements.”
But there are also many other elements that play into the safety of an ice road, from shoals and other underwater features to currents to snow cover and even sudden changes in temperature.
The 568-kilometre Tibbitt to Contwoyto ice road is of particular interest to engineers, partly because it’s the longest heavy-haul ice road in the world, partly because of the importance of diamond mining to the NWT economy (it accounted for 51 per cent of the Northwest Territories’ economy in 2006), and partly because it’s been built over and over again for so many years, giving engineers a tremendous case study and launching Canada to a leadership position in ice road construction. The road has supported tens of thousands of trucks carrying millions of kilograms of freight, fuel, construction materials and assorted essentials to the NWT’s Ekati, Diavik and Snap Lake diamond mines, and, for a short time, Nunavut’s Jericho mine (and before them the Lupin and Salmita gold mines).
It has also taught the people who build winter roads – in this case Nuna Winter Road Services and the Tibbitt to Contwoyto Winter Road Joint Venture – a lot about their product. “The big thing we’ve learned is that if you follow a risk management approach, you can raise the loads on the ice compared to what they were doing 20 or 30 years ago but still keep the risk of something bad happening to the same value that it was back then,” says Proskin. By using ground-penetrating radar to profile the ice, monitoring and carefully recording ice conditions, establishing a list of rules of how you operate vehicles on the road, and training drivers to understand the need for speed limits and spacing requirements, the risks are more or less controlled.
“The riskiest part is pioneering the road,” says Proskin. “When you are the first guys going out to pioneer a path and start clearing snow – and that’s usually the first thing you do because you want to clear the snow to promote natural ice growth because snow is an insulating layer – you have to be particularly careful.” For short sections of ice road, the pioneers may go on foot, with guys roped off and wearing survival immersion suits while they manually measure the ice. Longer routes use amphibious vehicles to profile the ice while the operator is safely seated in a vehicle that, if it breaks through, will float and give the guy a chance to escape. The workers verify the ice thickness before they allow any other equipment to go on the ice.
After that, crucial steps include tracking ice growth, measuring and recording thicknesses, andkeeping people off the ice until it’s tested, evaluated and approved.
“With good planning and route selection you can avoid a lot of the variables right away,” says Proskin. For example, the builders of the Tibbitt road have learned that, by clearing a path that is 30 metres wide, they can eliminate a lot of problems associated with snow. “They have a good buffer zone so traffic doesn’t need to travel anywhere near the snow banks, where the ice tends to be thinner” he says.
New routes pose greater challenges because builders often rely on local knowledge to identify potential problem areas. A contractor new to an area will have to spend more time identifying possible issues like shoals or currents.
In an ironic twist, a warming climate is further complicating the process of building in and for the cold. Melting permafrost has been wreaking havoc with roads and foundations in the North, and has gradually shortened the operating window for the Tibbit to Contwoyto ice road. As engineers and builders come to understand the effects of climate change, their ability to adapt – which has always been a strength of Northern construction workers – will be further tested.
