by Russell J. Kenney & Michael E. Kenney The exterior insulated finish system, or EIFS, has been on the market in America since the early 1970s. EIFS came here from Europe, where it had been used successfully since the late 1940s, gaining popularity as an effective and affordable way to renovate older buildings and restore buildings that were damaged in the Second World War. Unfortunately, the version of EIFS that was brought to this country was very different from the system that had worked so well in Europe. Modifications were made to the system with very little testing and engineering analysis. Problems started to crop up soon after EIFS entered the U.S. market, and as most people know, North America had widespread EIFS failures in the 1980s and 90s. Our company has prospered investigating many of those problem installations, serving as consultants in court cases involving everything from houses to high-rises. We've learned a lot about why and how EIFS can fail, but we haven't given up on it as a system. EIFS has advantages: It's fast, it's economical, and it offers a lot of control over style and appearance. And done right, it works. If you understand the design issues, the materials, and the installation process, you can get good results with EIFS. We don't just investigate failures — our company has supervised millions of square feet of EIFS work on new and existing buildings, and we have confidence that those installations will perform acceptably. As a result of our investigations of EIFS problems on buildings nationwide, we've proposed a number of changes in American codes and standards that apply to EIFS. Some of our recommendations have been adopted by the codes or by manufacturers, and some haven't. Since everyone hasn't seen fit to change their specifications, we've developed our own standards for jobs we supervise. Our company reviews plans, writes specifications, and inspects or supervises EIFS work on site. We provide advice on system design, materials selection, and installation methods. How the system is installed is usually the critical factor, but the design and the materials can also affect performance.

To put EIFS cladding on a building, the EIFS contractor first attaches expanded polystyrene (EPS) insulation board to the wall structure. This rigid foam base then gets covered with a base coat formulated from water, acrylic polymer, Portland cement, aggregates, and fillers. Fiberglass reinforcing mesh is embedded in the wet base coat. After the...

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