While laboratory testing per the North American Fenestration Standard establishes the Performance Grade of a fenestration product, leaks originating from surrounding wall or roof conditions or substandard installation practices can render even this rigorous testing incapable of accurately predicting actual jobsite performance. Field testing during or immediately after construction, but prior to the installation of interior finishes, should be specified.

To perform as intended, an installed window must be an effective amalgam of many components. Among the possible combinations, there’s a “sweet spot” in performance trade-offs at which you’ll find optimum energy efficiency, structural integrity and integration with building envelopes. In the process, there are many types of sealants that play a role—including expanding aerosol polyurethane foams, which can greatly enhance the installation quality of prime and replacement fenestration products by sealing the rough opening against air leakage. Applied in the gap between the rough opening and the window or door frame, foam expands to assume the shape of the gap and hardens to provide a highly effective air barrier. When foam sealant that is not formulated for door and window installation is used, though, the pressure exerted by the foam as it cures and expands can induce frame deflection and compromise proper operation of sashes.

More and more, architects are seeking ways to bring the outdoors in, melding a building seamlessly with its outdoor environment. Multi-panel door systems offer an increasingly popular way to accomplish this. Not only do multi-panel door systems offer aesthetic and health benefits due to improved indoor air quality and daylighting, technological improvements also allow these systems to occupy a greater area in the building envelope without compromising overall Yglesiasdoors. NAFS-17 specifies five different configurations and descriptions of how to designate folding door units of from two to five panels. In addition to testing for air infiltration, water penetration and structural performance under wind loading, folding doors are tested for deflection, force to latch, force to engage, thermoplastic corner weld strength, deglazing, and operating cycle/slam withstand.