Issue link: http://digital.canadawide.com/i/178323
October 2012 ANNUAL INDUSTRY FEATURE: Insulation Book your ad space now: Dan Chapman 604.473.0316 Alexander Sugden 604.473.0358 Fibre-reinforced concrete panel cladding systems from Synstone, Fort MacLeod, Saskatchewan. As well as posing a risk to health and safety, using a product that has not been approved could put contractors and others on the wrong side of the law. A few years ago, under an Ontario government program that encouraged better insulation, a company did retrofits with a product that contained a dangerous substance known as UFFI — urea formaldehyde foam insulation — which was banned in Canada about 30 years ago. It had been ripped out of homes across Canada beginning in the late 1970s because of toxic off-gassing, but was now being installed again. In 2009, Canada Border Services was alerted to guard against further imports and a cease-and-desist order was issued against Retrofoam of Canada Inc. Dalgleish wants to avoid a repeat of the UFFI debacle and warns that not only must the product meet the standard, but that installers must also be qualified. CUFCA has a certification program for that. "The installers combine chemicals at the site. The process and the end-product depend for their quality very much on the expertise of the installer," Dalgleish says. Occasionally, however, an issue of subpar envelope construction stems not from any failure to follow a regulation, but from a misunderstanding, even at the design level, of the precise quality and attributes of a material being used. "Precast is much less permeable than cast-in-place concrete. So the need for a vapour barrier is often not there when using precast panels for the envelope," says Don Zakariasen, director of marketing for precast products at Lafarge North America. Recently, he says, some designers have chosen to ignore the special properties of precast concrete, and design systems that attempt to mimic the drained rain control systems for brick or stucco veneers. But concrete's requirements are different from those of brick or stucco and it is a far better air and vapour barrier than either (the porosity of brick is over 100 times greater than precast concrete). "Architectural precast concrete-wall assemblies are designed to provide effective control of Building Envelope p.12-19Building Envelope.indd 19 air infiltration and moisture penetration. Through the proper understanding of building science, particularly the use of insulation and the treatment of the joints between interfacing materials, an efficient design can be achieved. Double-wythe insulated wall panels are the optimum solution," says Brian Hall, managing director for sustainability and business development at the Canadian Precast/Prestressed Concrete Institute. The very low porosity of the plantfabricated precast sandwich panel provides a robust weather barrier. "The interior seal acts as the air vapour seal and is installed from the exterior. The introduction of an air cavity compartment behind the full face of the wall into this type of system is not recommended. In addition to the impermeable nature of these panels, an intentional air cavity can be detrimental to the performance of the envelope," says Hall. The traditional afflictions of envelope systems still persist, however, from inadequate drainage to leaky flashings. "A lot of remedial work is being done on envelope issues. One of the biggest growth areas for some of our products has been in remediation," says Ross Power, president of Power House Building Solutions, a distributor of building envelope products. One of these is Pre-Proof waterproofing. "It's applied directly to the soil or the raft slab before you pour the main concrete slab," Power says. It is always preferable to avoid the need for remediation. Jesse Douglas, marketing manager at Gracom Masonry, offers some tips on getting both good prices and quality installers for cladding products. "Specify performance criteria for equal products. Pre-qualify contractors. Don't just rely on how long a contractor has been in business — they may be on the verge of bankruptcy. Better to go with one that's only been around for a short while but can prove financial stability, has a great safety program and well-trained project teams. Also, ensure that the inspection criteria and quality standards are outlined in the specifications." ■ AUGUST 2012 /19 7/13/12 9:56 AM