The 2017 hurricane season left an estimated $190 billion in damages, and the recent devastation of hazardous weather conditions caused by storms like Hurricane Florence still remains to be seen. All of this has prompted developers to seek out high-performance cladding options for High Velocity Hurricane Zones (HVHZ). Looking beyond traditional building materials such as brick and stone, the challenge has been finding durable cladding with a versatile aesthetic.
Fiber cement has emerged as a compelling option for residential, retail and commercial buildings. Particularly attractive in coastal areas and regions susceptible to hazardous weather conditions such as hurricanes, fiber cement offers a variety of textures, colors and finishes that deliver high-performance weather resiliency to satisfy the strict requirements of HVHZ.
Florida Set the Standard
HVHZ is part of Florida's building code established in Miami-Dade and Broward Counties, following 1992's Hurricane Andrew. The category 5 storm damaged or destroyed 163,000 homes. Recognizing the consequences of inadequate building regulation, Florida developed a set of comprehensive codes, including the HVHZ designation. Given its rigorous requirements, HVHZ is now the nationwide standard for storm resiliency.
Miami-Dade County maintains a checklist for cladding products that have been tested and approved for use in an HVHZ. This checklist includes detailed manufacturer and product information as well as current test results and reports. Fiber cement products, including our Architectural Wall Panels (AWP) and Sierra Premium Shake, are approved by the state of Florida and fully vetted as suitable for hurricane-prone areas.
Wind Loads and Rain
The capacity to withstand severe wind pressure enhances fiber cement's ability to resist water penetration during storms. For example, Nichiha addresses moisture management in two ways. As a first layer of protection, our Ultimate Clip Installation System and the recently updated Ultimate Clip System II limit the flexing of joints that could create temporary openings for moisture. In the event that moisture penetrates the wall, the built-in rainscreen adds another layer of protection with drainage channels and weep holes. These ensure any residual water will drain out from the cladding and allow air to circulate, reducing the risk of mold and water damage.
When tested against industry standards (ASTM E 331 and AAMA 509-14), fiber cement has been proven to resist water penetration when properly installed; in the rainscreen tests, an average of only 0.01 oz/ft2 of moisture was able to penetrate the walls even with simulated wind and water striking the panels at roughly 75 miles per hour via static and dynamic pressures of up to 12 pounds per square foot (PSF).
Ideal for use in an HVHZ, horizontally-installed AWP and the Ultimate Clip System are equipped with an allowable design pressure of 95 PSF, which would indicate a severe wind event. This design pressure also accounts for structural overloading at 1.5 times this number without product failure. The framing can be upgraded to 16-gauge metal from 18-gauge metal to additionally strengthen the hold of the panels' fasteners. Sierra Premium Shake is able to withstand allowable wind loads of up to 55 PSF when installed with screws in a blind nail application or 110 PSF with face fastening.
Sophisticated Style and Resiliency
Fiber cement's durability extends to its aesthetic. Available in a wide array of textures and finishes suitable for projects of all shapes, markets and sizes, fiber cement easily mimics the appearance of natural materials such as wood and stone without the maintenance worries. In fact, the finish on fiber cement boards and wall panels can retain its appearance for 15 years or more—even in varying weather conditions. The material's versatility also allows it to be installed in a variety of configurations for design flexibility.
To learn more about how modern fiber cement can increase the resilience of homes and businesses in the face of hurricanes and other environmental threats, download our white paper, Improving Resilience in Severe Environments with Advanced Fiber Cement.