Issue link: http://digital.canadawide.com/i/687429
Porcelain cladding solutions from Engineered Assemblies. J UNE 2016 | 27 Interest in the system has been gaining momentum, with several new projects awarded in the last few weeks. A concrete-based technology for cladding, invented and developed in North America, is also attracting interest. Boasting panel depths from 0.75 to two inches, patented ARCIS ultra-thin precast, prestressed technology provides a lightweight panel with the strength and versatility of concrete. The panels use non-corrosive, high-strength stainless steel pre-stressing – pre-tensioned cable strand – placed longitudinally and transversely in the panel face to provide strength, crack control and durability. "It's a precast cladding that works very well with a rainscreen sys- tem. It has the same wide variety of finishes and colours you get with a traditional precast concrete panel that would be a lot thicker," says Jim McKay, national con- tracts manager, precast concrete solutions, at Armtec. The modern practice of installing electrical cables and raceways within or next to the underside of roofing systems is creating a potential hazard, according to the Roofing Contractors Association of British Columbia (RCABC), which recently issued an alert on the subject. The wide prevalence of structural metal roof decks or substrates, used for an estimated 85 per cent of flat roofing systems of all kinds in most parts of Canada, and the growing use of screws and metal fasteners, instead of the traditional mop- ping down with hot asphalt, are likely factors in increasing the risk of damage to the electrical system, says James Klassen, a technical adviser at RCABC. "One rea- son it's more of an issue with metal decks is that they have flutes or ribs, recesses in which electrical conduit can be run. When a roofer installs a roof system, these components are hidden from view," he says. The issue has emerged partly as a result of today's better documentation of design. Non-intrusive detection methods for this type of metal problem are not a solution, however, as they are not reliable for locating conduit damage, Klassen says. Klassen notes that that RCABC's concern around the issue is supported by experts, including those who write the National Fire Protection Association's NFPA 921, a guide for fire and explosion investigations. A manufacturing plant recently lost power because of roof fastener damage to its electrical system. "It took a day or two to figure out the problem," Klassen says. The RCABC would like to see a code change to deal with the issue. One solution, Klassen says, is to suspend electrical conduit in cable trays beneath the roof deck. The RCABC has some recommendations on its website. A Roofing/Cladding Materials VIBRATION ISOLATION SOLUTIONS Providing Products & Expertise in Noise & Vibration Control Since 1980 Western Canadian Representative for Mason Industries 604-294-9495 | info@vibra-sonic.com Rooftop Spring Curbs with high defl ection springs for rooftop HVAC equipment. www.vibra-sonic.com Leading providers of high performance VIBRATION ISOLATION & SEISMIC RESTRAINT for HVAC, Plumbing, and Electrical equipment.