A standard for the testing and evaluation of Exterior Insulation and Finish Systems (EIFS) in commercial applications, recently approved by the Underwriters Laboratory of Canada (ULC), will silence some critics of EIFS, a cladding system that has come under some criticism over the past decade.
Almost eight years in the making, the standard (known as ULC S716) will be published this spring, giving EIFS more credibility in the building and design community, says Kevin Day, chair of the EIFS committee that hammered out the ULC standard. “It means there is a minimum acceptable standard available for anybody who wants to set criteria for the use of EIFS.”
Often incorrectly called synthetic stucco, EIFS are actually multi-layered exterior wall systems, composed of insulation board (typically made of polystyrene), which is secured to a polymer and cement base coat reinforced with glass fibre mesh. The’re covered by a textured exterior acrylic coat that is colourfast and crack-resistant.
Along with protecting moisture-sensitive components of the wall assembly behind the cladding, a successful EIF system provides a method of draining incidental moisture to the exterior. Developed in Europe in the 1950s, EIFS were introduced to Canada and the U.S. in the 1980s.
Today, while EIFS are commonly specified on many commercial lowrise buildings, such as big box retail outlets, in the 1980s and ’90s these systems were associated with a number of structural failures in the U.S. and the billion dollar leaky condo crisis in Vancouver, where poor performing systems resulted in severe water damage to wood wall assemblies.
Day says while some criticism of EIFS has been justified, the new standard should calm the fears of critics. “By having a standard on cladding reached by consensus we will make people realize that the problems in the past were probably more project-related than endemic to the systems.”
ULC S716 was developed with the guidance of the National Research Council, the Canadian Construction Materials Centre (CCMC) and extensive input from the Canada Mortgage and Housing Corporation. “It is not a standard simply developed by the EIFS industry,” points out Guido Rapone, of Durabond Products and president of the EIFS Council of Canada. The new standard is based essentially on the CCMC guide for evaluating EIFS systems.
Key points of ULC S716 include: the durability of EIFS; adhesion properties of all the components, including the water-resistant barrier, base coat and finish, and the finish’s resistance to ultraviolet rays, salt air and water.
Rapone says by clearly identifying acceptable EIF systems, the new standard opens the door to widespread use in municipalities. “It eliminates a lot of confusion building officials have had, which often centres on water-resistant qualities of systems.”
Day says the next step is to achieve a ULC standard for installation and design of EIF systems. While some observers believe that could happen within a year, Day isn’t holding his breath. “It took eight years to get this standard. We had to stop, retool and redefine our scope. It was a very political process before it was a technical process.”
Realistically, installation and design standards will take another 18 months to two years to complete, says Rapone. “When that is achieved, we will have a complete guide on how to install an EIF system on a wall.”
To meet the new testing standard hasn’t come cheaply for EIFS manufacturers. “Most manufactures have invested big bucks on research and development to get to the stage that their product meets ULC S716,” says Rapone, noting the testing standards are “probably the most stringent” of all cladding systems on the market today.
Nonetheless, EIFS manufacturers are applauding the move because it is a big step towards legitimizing the product in the eyes of the design community.
Rapone says specifiers who select EIF systems that don’t conform to the new standard are taking a risk that their system won’t perform as it should, ultimately causing failure.
Day points out that ULC standard is more substantive than its U.S.counterpart. “We are required by the CCMC to incorporate durability testing, which they don’t have to do.” Operating within the NRC’s Institute for Research in Construction, the CCMC is an evaluation service for all types of innovative construction materials, products, systems and services.
One of an EIF system’s strongest selling points is its thermal efficiency, points out Oscar Chiarotto, of Lido Wall Systems, a major EIFS contractor in the Greater Toronto Area. “By placing the insulation on the exterior of a building, you eliminate all thermal breaks within the wall. Inserting the same amount of insulation in a stud cavity will result in lower thermal efficiency.”