If there’s a common language in modern architecture, it’s the vocabulary of natural daylight. Opening interiors to introduce more daylight is becoming a design imperative, and once-dark corners of the built environment, such as stairwells, elevator enclosures, and parking garages, are now illuminated with welcoming natural daylight.
Few dispute the need: The world’s largest independent assessor of workplace effectiveness, Leesman, surveyed a quarter-million employees in 69 countries on the value of daylight. Nearly 76% of the respondents highly valued daylight in the workplace. However, just under 57% are satisfied with existing access to it in their workplace.
If daylit spaces are the goal, fire-rated glass is the delivery vehicle. The challenge is, Chapter 7 of the International Building Code presents a thicket of specification detail. Manufacturers’ claims—such as relying on fire endurance ratings (20, 45, 60, 90, 120 and 180 minutes) or labeling a glazing product with terms like “thick” or “thin”—can also cloud the process.
Four common misconceptions:
1. Fire-protective glass is the same as fire-resistive glass. The life-safety differences between the two are vast: Fire-protective glass prevents the passage of the visible elements of a fire—flame and smoke—but it does virtually nothing to shield building users from potentially lethal radiant heat. Only fire-resistive glass prevents the passage of radiant heat that can result in spontaneous combustion and inflict severe injury and death. Fire-resistive glass is a passive, or built-in, life-safety barrier that can be counted on when active fire suppression systems such as sprinklers have failed.
2. Ceramic glass is the only wire-free fire-protective glass option. There was a time when ceramic glass was widely touted as the wire-free alternative to traditional wired-glass for flame and smoke separation. Last year, a patented, U.S.-made, wire-free, low-iron, 45-minute fire-protective glass product called SuperClear 45-HS-LI was introduced to the market. SuperClear 45-HS-LI meets all fire, hose stream, and safety requirements without any films or laminates at approximately half the cost of ceramic glass. Ceramics also have an amber tint, and have to be filmed or laminated to meet safety requirements, adding to their already high cost.
3. Fire-resistive glass limits design choice. There’s never been a better time to open interior design to unprecedented levels of natural daylight. Fire-resistive glass blocks fire, smoke, and radiant heat without films, laminates, wires, or tints. Low-iron, fire-resistive glass options from Safti-First—a vertically integrated, single-source, U.S.-based manufacturer of advanced fire-rated glass and framing systems—achieve the same clarity as non-rated glazing, and can help shape a uniform design aesthetic.
4. Only gypsum, brick, and other opaque materials meet ASTM 119/UL 263 for a fire-rated wall assembly. Not any more. Fire-resistive glass is, by IBC definition, a code-compliant transparent wall system. The code-compliance breakthrough of products like SuperLite II-XL, SuperLite II-XLB and SuperLite II-XLM by SAFTI FIRST, opens the door to an unprecedented range of interior and exterior applications.
As you weigh your design options, keep in mind the difference between fire-protective and fire-resistive glass. It’s time to use a new vocabulary to advance bringing natural daylight into the built environment.
View the important differences between fire protective and fire resistive glass in this short video.
