Pre-built shear panels provide protectiolt, desi$n flexibilfty

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IX/ITH increasing frequency, news

Y Y stories tell of the destruction of homes and loss of life from earthquakes, hurricanes, and high winds.

What was once thought to be a design and construction challenge limited to California, the Gulf Coast and the Atlantic Coast, is now being faced in many areas of the U.S. as the awareness of natural hazards grows. Consideration of seismic activity in the design of homes has become more prevalent in the Pacific Northwest, the Rocky Mountains, Alaska and Hawaii. The New Madrid seismic zone has a large potential to impact homes in parts of Tennessee, Illinois, Missouri, Kentucky and Arkansas. High winds damage homes in the Midwest and other areas far from earthquake zones and coastal areas.

The quality of structural framing materials plays a major role in how well homes stand up to such natural disasters. Builders, designers and specifiers looking for consistent and predictable framing performance under lateral loads caused by earthquakes and high wind, as well as to meet code requirements. are increasingly turning to prefabricated shear panels for their design needs. Lumber and building material professionals can enhance their service to builders by understanding a few key uses and benefits of shear panels.

Traditionally, shear walls were built on site, with a high degree of variability and unpredictable performance. They were time consuming to build and often resulted in wasted materials. Pre-built shear panels, such as the iLevel Trus Joist TJ-Shear Panel provide consistent and predictable performance under lateral loads and are easy to install. Such panels provide the added strength and support necessary for framing areas of the home where high lateral loads must be resisted. Typical areas of the home that require special attention to resistins lateral loads include narrow wall segments around garage doors, and walls with numerous window and door openings.

Beyond concerns with earthquakes and high winds, many builders use pre-built shear panels because of the design flexibility they provide for meeting code requirements. As homeowners have demanded more visually appealing and varied home facades, floor plans have become more complex with many narrow wall segments. Shear panels are a good way to build stable, narrow walls quickly and maintain high quality.

In addition to use in larger homes, the panels are popular in densely populated urban areas where lots are small and the homes have many narrow wall segments. Builders of al1 sizes are finding benefits from pre-built shear panels. Production builders like them for their consistency, performance and ease of use in replicating high volumes of floor plans. Custom builders like them for their design flexibility and performance.

Because they are assembled in a factory, pre-built shear panels can be engineered to precise specifications and manufactured to a consistently high level of performance. The panels undergo rigorous testing in controlled situations, allowing manufacturers to understand in detail how they may perform in real-world applications. With this expertise, manufacturers are in turn working with LBM dealers to help builders incorporate the panels into homes in a way that optimizes structural performance. For builders unaccustomed to construction for high lateral loads, pre-built shear panels provide additional peace of mind because their precision engineering and consistency can help them more readily pass inspection than site-built shear walls.

Well-designed shear panels balance four essential performance criteria: allowable load, stiffness, dampening and ductility. In essence, shear panels must resist lateral loads, but provide some flexibility and energy absorption. It is important that the panel performs in cooperation with other areas of the home to ensure structural integrity and promote life safety. Think of a shear panel as a tree in the windstrong and stiff enough to stand tall, but flexible enough not to snap. These are important features when high winds blow or the earth is shaking.

An added benefit of pre-built shear panels is that they are easy to work with and are available in a variety of widths and heights. With their one-piece, modular construction, one person can easily install most sizes of panels. In the case of TJ-Shear Panel, it mounts to the foundation slab or stemwall with only two nuts and two washers, making installation quick and simple. Lag screw holes for connection to the framing top plate are pre-drilled at an angle for easy access. The panel is pre-drilled for electrical wires, helping builders save time and eliminating guesswork.

As more builders become aware of the range of applications for pre-built shear panels and the benefits they provide, dealers can anticipate increased inquiries. One doesn't need to be a technical expert in earthquake or wind design to help builders understand the options available to them. With a quick call to your supplier or an Internet search, dealers can quickly leam about the types of pre-built shear panels and the technical experlise available to them.