October 2014

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W Thermal Wave The quesT for effecTive r-values is improving insulaTion and cuT Ting fuel bills by Godfrey Budd With today's intensified focus on ther- mal performance of the building enve- lope, the announcement of June 2013 from the Polyisocyanurate Insulation Manufacturers Association (PIMA) that its Quality Mark R-value program was being updated with a new test method for long-term thermal resistance (LTTR) is well timed. The result is that new LTTR values are slightly lower than those prior to the update, which took effect January 1, 2014. For instance, with a one-inch thickness, polyiso had an R-value of 6.0 using the old ASTM c1289-03 test, but has an R-value of 5.6 using the new ASTM C1289-13e1 test, according to a chart from Firestone Building Products Canada. The old test proved fairly accurate, with about a seven per cent error fac- tor. "Now, we've improved the testing method. The point of long-term thermal resistance testing was to put all polyiso manufacturing on a level playing field," says Tyler Cooper, Firestone's insulation manager. The US National Roofing Contractors Association (NRCA) has recommended that designers specify polyiso by thick- ness, not R-value, "based on the required R-value for specific project conditions." In cases where R-value has been speci- fied during the transition period, the NRCA says contractors should consider submitting requests for information to clarify whether the old or new LTTR values are applicable. Despite the focus on thermal per- formance and on-site installation effi- ciency of recent years, new products that address both issues can take a while to catch on. A few years ago Firestone's Isogard was introduced. "Before that, many in the industry used gypsum for cover board, but it's difficult to work with. So we made a product from polyiso. It's light, easy to work with and provides additional R-value," Cooper says. "It took a while, but we're now see- ing explosive growth in demand for this line. It's really catching on," he adds. In 2012, Firestone introduced an upgrade to the earlier product called Isogard HD (high density) Composite. It consists of half-inch Isogard cover board Above: A Firestone licensed contractor installs the ISOGARD HD cover board on a retrofit project. The lightweight alternative to gypsum also provides an addition R-value of 2.5. Below: A Canada Post Corporation facility in Toronto, completed in 2012, is covered with a fully-adhered EcoWhite EPDM membrane. Beneath it, two layers of three-inch ISO 95+ Insulation, tapered insulation and ISOGARD HD comprise an R-value of over 30. Photos courtesy Firestone Building Products. Insulation

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