Provincial Engineering & Geoscience Week

8 | W I N N I P E G F R E E P R E S S P R O V I N C I A L E N G I N E E R I N G & G E O S C I E N C E W E E K 1558 Willson Place Winnipeg, Manitoba (204)453-2301 FACILITIES ENVIRONMENT COMMUNITIES INFRASTRUCTURE 1702-MB-Geo-Quarter-ad-2.indd 1 2/16/2017 6:48:17 PM B uilding codes were a lot less strict when Rapunzel was first asked to let her hair down from a balcony a couple hundred years ago. The early 19th century character made famous by the Brothers Grimm didn't have to worry about heat escaping her tower's envelope, the environment or the thermal conductivity of the structure's components. Her biggest concern, presumably, was not having every hair on her head torn off when her knight in shining armour used her golden locks as a ladder to climb up and rescue her. A new test being done in partnership by the University of Manitoba and Red River College hopes to bring efficient balcony construction into the 21st century by finding the most cost-effective means of constructing balconies on apartment and condominium buildings while simultaneously meeting increasingly strict building codes. "It's a problem that's always been there but the industry is finally acknowledging it," said Sarah Boila, a structural engineering master's student at the U of M. "The more heat that escapes, the more you have to heat it from the inside, which means the heating system is working harder and the cost is higher to the owner and tenants." The Balcony Test Program is being conducted in a temperature-controlled, double-sided thermal chamber at RRC. A variety of data is being gathered from concrete slabs on both sides of the chamber, one half is set to 20 C while the other is at -30 C. Balcony design typically involves a reinforced concrete slab cantilevered beyond the exterior wall. The concrete and reinforcing steel both act as a thermal conductor, cooling the building from the outside during the winter months. What results, however, is a lower temperature in the concrete slab and interior surfaces, which often leads to condensation. If it's not seen or ignored, condensation can not only cause a building's structure or architecture to deteriorate but also lower air quality due to mould growth. Kevin Knight, a research professional at RRC's Building Envelope Technology Access Centre (BETAC), says while it's still early days for the testing and prototyping, he is optimistic about finding a more affordable solution for balcony construction. "Some buildings have had to drop the balconies (as a feature) because of cost. They require separate structural steel to support them which adds a lot to the costs of the building," he said. That presents a conundrum to building owners — eliminate the balconies in the interests of keeping costs under control but also lose a primary selling feature. "Most people still like the balcony if they're in a high-rise building. It's a significant extra cost considering how many square feet they are," he said. Structural materials for the test include stainless steel and carbon fibre reinforced polymer, which have superior conduction properties compared to conventional steel reinforcement and can therefore maintain the structural integrity of the connection without compromising thermal performance. Insulation materials to form a barrier between the balcony slab and the wall include Armatherm 500, ultra-high weight polyethylene, ceramic, and Styrofoam Highload 100 with ceramic in the compression zone. Because this test is literally starting from scratch, efficiencies also need to be found with the process itself. For example, the first slabs put in the chamber were each overloaded with 100 sensors but the first results will help determine the optimal number of sensors, perhaps half as many. "We have to iron out the kinks every step of the way," she said. Apartments or condos with balconies have traditionally presented heating challenges, Boila said. "You end up with a hole in the insulation. In winter, you've got heat travelling through the structural system which causes your building to lose heat and be less efficient," she said. Many would-be high-rise dwellers won't appreciate the intricacies that go into balcony installation but they'll be happy with the outcome, Boila said. "It'll be a healthier building. Because it's not losing heat and it's not mouldy, the people are healthier and they're happier because they're paying less (for heat)," she said. ❚ Building a better balcony By Geoff Kirbyson for the Free Press Sarah Boila (left) and Kevin Knight with a manufactured concrete slab thermal break. Photo by Darcy Finley

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