Zinc meets safety and durability standards for city’s Central Communications Center
To meet the expanding safety and emergency response needs of a rapidly growing urban area, the City of Raleigh, N.C., hired architecture and engineering firm Clark Nexsen, Raleigh, and AECOM, Raleigh, to program and design the new Central Communications Center. Its major functions consist of a 911 emergency call center, an emergency operations center, the area’s main data center, and a traffic control center.
Issues of safety, durability and occupant comfort were major factors driving the design strategies for the facility. In addition to being constructed of durable materials, the exterior wall systems are blast- and ballistic-resistant to meet safety and resiliency standards. The City of Raleigh was looking for a natural and durable material, preferably manufactured within 500 miles of the project. They settled on Jarden Zinc Products, Greeneville, Tenn. According to Bob Thomas, of Cornelius, N.C.-based Styro Systems Carolinas, the local sales representative for Jarden Zinc, being able to source zinc through a regional manufacturer rather than overseas was instrumental in a successful installation.
Clark Nexsen specified the Jarden Zinc Cassette Panel, which is a true dry-joint system that uses neither sealants nor gaskets. This means no dirty streaks, no repetitive replacement of gaskets or sealants, and low maintenance for the building owner-an extremely important factor when using a 100-plus-year material. But changes in temperature can affect the integrity of a metal wall panel if the system is installed without regard for thermal movement. As metal panels increase in temperature, they get longer. Likewise, when they cool, they shrink. Zinc has nearly double the thermal expansion rate of a similar painted steel panel.
Metal wall panels are installed by direct fastening or with metal clips. The direct method of attachment does not provide for thermal movement of panels and may result in the distortion of the panel. A simple clip design, where the clip is rigidly attached to the building structure but slip-connected to the zinc panel, allows for differential movement between the panel and the clip.
Zinc Cassette panels are designed specifically with zinc in mind. Using clip fasteners that allow the panel to move freely in response to thermal cycling also makes it necessary to deliberately pin or fix the panel at some point along its length to prevent it from migrating out of its intended location. The pin location of the panel will be at the top in a vertical application and the center in a horizontal location. By fixing a horizontal panel in the middle, the expansion and contraction is effectively cut in half.
Being a true dry joint system, zinc cassette panels use neither sealants nor gaskets. This means that there are no dirty streaks, no repetitive replacement of gaskets or sealants, and low maintenance for the building owner-an extremely important factor when using a 100-plus-year material. If you are looking at cladding your building with metal, the zinc facade system provides architects, specifiers, and builders with versatile, long-lasting, cost-effective, and environmentally friendly wall panel systems. Zinc cassette panels are engineered for quick, easy, cost-effective installation.
Given its long history, zinc is a natural choice for many challenging architectural applications. Its excellent formability allows for creative expression through the design of intricate shapes and forms in roofing including curved roofs, wall cladding, dormers, steeples, guttering and other water-shedding components. In addition, its natural beauty perfectly enhances the interior design of counter tops, bar tops, wall panels, lighting fixtures, and many other decorative ornaments. Architects choose zinc for its natural beauty, durability and cost effectiveness.
If you are looking for LEED certification points, zinc is the perfect choice for your project. Since zinc is considered an essential element for life, it is by nature an environmentally safe and friendly material that is found in water, soil and all living things. It is 100 percent recyclable at the end of its useful life and maintains its physical and chemical properties, significantly reducing the need for new raw materials. Today, more than 30 percent of the zinc consumed is obtained from recycled materials. Zinc requires far less energy in its extraction, processing, and recycling than other nonferrous metals.
The use of zinc in architectural applications continues to grow both in the United States and internationally. Given its natural durability, ease of forming, innate beauty and cost effectiveness, people worldwide continue to discover the many advantages of this timeless material.
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Grady Chafin is a manager of commercial sales at Jarden Zinc Products, Greeneville, Tenn. Chafin started his career at Bristol Metal in 1993 then moved on to Outokumpu in 2000. He joined Jarden Zinc Products in 2006. To learn more, visit jardenzinc.com.
PHOTOS: JIM SINK