January 23, 2019
by Matt Thomas
When Hurricanes Florence and Michael struck North America in 2018, many residents and business owners had to deal with major flooding and destruction. Due to the impact of extreme storms on homes and businesses, architects and builders across the United States are more mindful than ever of the products being used, proper ratings, and what to look for when building and rebuilding.
Even though the Miami-Dade certification, one of the strictest test protocols in North America, requires glass walls to have sufficient ratings for impact resistance and cyclic wind-pressure loading, storms such as Maria, Harvey, and Irma can still create devastation across North America. As glass wall systems become a staple in architectural design, it is important to recognize Miami-Dade compliance is only the starting point. On its own, it will not hold up against superstorms. For safety, security, and longevity, more is needed.
As architects and owners are rebuilding in hurricane zones, here are six key features to look for in glass wall systems to ensure performance is above and beyond Miami-Dade ratings.
Reinforced structural posts
It is important to look for a folding glass wall system with reinforced vertical posts (or astragals) down each panel side for added performance. This design means glass walls pivot on and are hinged to either side of the vertical post instead of pivoting with rollers with ball bearings. The post itself should have stainless steel wheels connected to a track—just like the wheels of a train—that can run along the track without pivoting. These reinforced vertical structural posts provide incredible strength against high winds and water blowing against the system.
A floor-supported system
Many glass wall systems are hung from a top support and only use a floor rail to guide the panels’ path, but heavy, moveable panels require an incredibly strong header. If not, the glass walls are more susceptible to high winds. Floor-supported systems, on the other hand, use gravity to their advantage with all of the weight supported on the floor. This extra stability enables the glass wall system to withstand hurricane-force winds.
Extreme weather means water, mud, and other particulates will be pressed up against the glass, seeping in through the floor tracks, and ruining wood and carpet. A high-performance raised sill is the most weather-resistant sill available and prevents both static and dynamic water penetration, also yielding higher pressure ratings against heavy wind loads. This means even without an overhang to shield them from the elements, the glass walls can squarely face even the strongest winds.
This goes without saying. It is not only crucial to incorporate extruded aluminum frames and panel profiles (an absolute must when it comes to protecting against the saltwater-filled air), but also to ensure the rollers and hinges themselves are stainless steel. When salty wind and rain beat up against a system, the parts can quickly rust and corrode, weakening its performance against future storms.
Vandalism and burglary are real issues once residents have been evacuated, leaving homes and businesses unprotected until cleanup efforts are under way. Looters usually look for easy points of entry, often breaking in through sliding or folding glass walls. A latch and deadbolt is not enough. One should look for a multipoint locking system that also includes top and bottom locking rods so each glass panel can be securely locked into the upper and lower frame with polyamide-capped locking rods. This is paramount when securing the opening and it also adds to the glass wall’s ability to withstand strong winds and water intrusion.
Ratings for Miami-Dade, the American National Standards Institute (ANSI) and ASTM are just the baseline. A glass wall system in hurricane country ought to be certified for all-climate performance and durability, such as the American Architectural Manufacturers Association (AAMA) rating for air, water, structural stability, and forced entry, as well as National Fenestration Rating Council (NFRC) certification for air leakage and condensation resistance.
The past hurricane season demonstrated Miami-Dade County certification is just the starting point when the top priorities are safety, security, and structural performance. During this rebuilding process and when moving forward, architects and builders should look for glass wall systems that go well beyond the Miami-Dade standards toward peak performance.
Matt Thomas is the marketing director for NanaWall Systems. As a marketing practitioner, he meshes his technical and communication skills with his sense for design. He has worked and lived in Israel, Singapore, New York City, Los Angeles, and now the San Francisco Bay Area. While working for NanaWall Systems over the last seven years, the company has engineered and designed more than 25 award-winning systems and has grown to include 24 showroom and design studio locations across North America. Thomas can be reached at firstname.lastname@example.org.
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