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The Outer Limits THE LATEST SOLUTIONS IN WATERPROOFING ARE MORE EFFECTIVE, MORE ENVIRONMENTALLY FRIENDLY AND EASIER TO APPLY THAN EARLIER SYSTEMS by Stefan Dubowski D Dave Hales remembers well his house in Scotland – built in 1886 with walls constructed of about two and a half feet of stone, timber, lath, horse hair insulation and plaster. It certainly was sturdy. But while the house largely withstood the elements for more than 100 years, it didn't entirely thwart the rain. "It leaked like a sieve," says Hales, who now lives in the Toronto area, and is the Canadian managing partner of VaproShield Inc. VaproShield is one of a number of companies working to improve waterproo ing technology. No surprise, the latest products do a much better job of waterproo ing than the materials used to construct buildings a century ago. But they also vastly improve on advancements made just a decade or two behind us. Waterproo ing systems last longer, are more effective, environmentally friendly and are easier to apply. Hales points to the genius of GORE-TEX – the waterproof, breathable clothing material – to describe VaproShield's WrapShield line of weather resistive and air barriers for buildings. GORE-TEX allows moisture to escape, so the wearer stays dry. WrapShield, a water-resistive, vapour-permeable air membrane, likewise lets moisture escape from the building envelope while protecting the structure from wet weather. "We know buildings are going to leak," Hales says, noting that buildings absorb moisture, and it's impossible to keep the structure completely dry during construction. "Let's allow the moisture that does get in to get out." WrapShield consists of an inner carrier layer, a middle vapour-permeable and air-retardant layer, and an outer carrier layer. The latest iteration features integrated tape at the horizontal seams for quicker installations. WrapShield SA (self adhered) has a unique air-permeable adhesive covering the back. "In all types of rainscreen designs, the secondary weather resistive barrier layer is critical, and both WrapShield and WrapShield SA enhance the rainscreen construction with the ability to be static," Hales says. "WrapShield SA offers a quicker, less labour-intensive, tape-free solution." VaproShield's WrapShield SA was employed in a mixed-use building in Toronto. Like many of the projects that incorporate VaproShield's products, the building, designed by Kasian Architecture, is under consideration for LEED accreditation. Longevity is central to VaproShield's environmental story. If the company's product helps buildings last longer, that reduces the energy and material-extraction expenditures required for repairs and reconstruction. It's prudent considering how poorly some buildings were constructed in the past, Hales points out. "We've seen condos go up that, three years later, are being demolished because they're just covered in mold and rotted out," he says, adding that WrapShield's 20-year warranty helps assure builders that projects using this product won't face the same fate. Dryvit Systems Canada introduced its newest innovation a just few years ago: AquaFlash. It's a lexible, water-based polymer material used in conjunction with a mesh to seal substrates around windows, doors and other openings. It's an alternative to the rubberized asphaltic membranes used for transition areas, says Peter Culyer, Dryvit's marketing and technical services manager. AquaFlash is easier to apply than conventional transition membranes. With conventional membranes, applicators have to use three layers – an adhesive, the membrane and another material for a positive overlap. With AquaFlash, the applicator lays down the adhesive, then the membrane, and the job is done. A luid-applied technology, AquaFlash is formulated with the appropriate emulsion to bond with adhesives better than typical polyethylene membranes do, Culyer says. "The issue of adhesive compatibility meant that often supplemental adhesion with mechanical fasteners had to be used in those areas where the transition membrane bridged onto the substrate a little bit too far," he explains. "That introduced an extra step, and a thermal compromise. The labour involved is quite time-consuming with traditional transition membranes. With the luid-applied, it's much faster and is seamless." Dryvit also offers lashing tape for transitions, but Culyer says AquaFlash is the superior product. Why offer the lashing tape, then? He points out that it takes time for customers to transition to the latest technology. "Once they do, however, they ind that the luid-applied products are bene icial in terms of labour savings," he says. AquaFlash was used on Casino New Brunswick in Moncton, completed in 2010. Fundy Drywall Ltd. had the contract for the rough openings. Dryvit conducted an orientation to introduce the Fundy crew to AquaFlash. "They immediately realized the bene it from a labour standpoint," Culyer says. "They continued the rest of the rough-opening protection with AquaFlash." Protection is a priority for Peter Hamilton, vice-president of Eagle Restoration Inc. The company specializes in rehabilitation and protection of structural concrete slabs such as those found in parking garages. As an executive with a specialized waterproo ing company, Hamilton has seen the industry shift from the epoxy-based solutions in the past to urethane systems, which are more common today. But that doesn't mean urethane is the clearly superior material. Hamilton recalls that early urethane systems were quite soft, designed to bridge inevitable concrete shrinkage cracks and to help ensure that water didn't penetrate into the slabs. Yet those earlier solutions may have been too soft, Hamilton says. In high-traf ic areas, they wore faster than the epoxy Above: Approximately 5,000 square feet of VaproShield WrapShield SA Self-Adhered Water Resistive Vapor Permeable Air Barrier Sheet was used on this mixed-use building in Toronto, ON. Waterproofing p.40-45software_waterproofing.indd 43 JUNE 2012 /43 5/25/12 11:51:05 AM

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