Issue link: http://digital.canadawide.com/i/178323
according to the U.S.-based National Institute of Building Sciences. "People are looking to EIFS and more people are going to EIFS today because of the emerging energy codes. Designers are looking at our technology to see where it fits. As far as EIFS goes, the jury is in. It's more efficient," says Peter Culyer, manager for marketing and technical services at Dryvit Systems Canada. Recent study, he says, has focused on the issue of continuous insulation. Also, the role of some metal elements in buildings to act as thermal bridging in cold climate situations has been underestimated, according to some of the more recent research and analysis. Pointing to a technical paper by engineers at Morrison Hershfield, he says, "The study found numbers much higher for energy loss as a result of thermal bridging than was previously thought." It likely comes as little surprise that not every exterior insulation system achieves its stated R value. "It can be affected by Z-girts, for example, or any interruption in thermal insulation. The difference between EIFS and some other exterior insulation methods is that EIFS is continuous as insulation. There's no interruption as a result of the fastening. In a rainscreen stucco system, the insulation can be interrupted by Z-girts," Culyer says. There has been resistance to EIFS in the past, in part because the system was seen to be vulnerable to water penetration. "That's changed. The ability of the EIFS system today to handle moisture stems from the application and advances in water-resistant barriers – WRBs – that are now applied throughout the substrate. They provide a high level of moisture and air penetration resistance. The WRB that's used today meets all codified requirements for air barriers. EIFS came into their own some time ago and the science validates what the EIFS sector has been saying," says Culyer. The range of products that are aimed at EIFS, either exclusively or partially, testifies to their success. Products like Durex Stonetex and Gemstone from Durabond are applied with a trowel and were introduced about three years ago. "They are a good fit for EIFS and 14/ AUGUST 2012 p.12-19Building Envelope.indd 14 7/13/12 9:54 AM