Glass & Metals 401: Security and Fire-rated Glass FAQ

Answers to top questions about protective glazing

Blast & Ballistic FAQs

Q: Are codes for security glazing in educational facilities changing in the wake of recent events?

“With the tragic events that took place over the past years, there are many local and state jurisdictions currently looking into providing enhanced protection for schools of all levels, as well as other public buildings. Recently, Sen. Barbara Boxer and Sen. Susan Collins jointly introduced ‘The School Safety Enhancements Act of 2013.’ This legislation asks for $40 million to be dedicated annually for safety improvements and security assessments for U.S. schools. Additionally, the bill calls for the creation of an interagency task force that would ‘develop and promulgate a set of advisory school safety guidelines.’ The makeup of this task force will be key to any successes in improving school building security.”
—Ken Brenden, technical director, American Architectural Manufacturers Association

Q: What is the main concern when specifying blast- or ballistic-mitigating glazing?

“The main concern is an undefined or incomplete project specification. Designing for blast hazard mitigation or ballistic protection requires a total system approach. The system’s ability to provide a designed level of protection is only as good as its weakest link. With any enhanced protection, it’s critical that the event itself be clearly stated and the protection and hazard levels be defined. When designing for ballistic protection, the caliber of the projectile needs to be specified. Although a window or door can be designed to provide the necessary level of ballistic protection, it’s important to ensure the interface between the product and the structure itself maintains the same level of protection.”

Q: What standards exist for security glazing?

“Ballistics glazing is tested to Underwriters Laboratories 752, National Institute of Justice (NIJ) 0108.01, or ASTM F1233. Intrusion-resistant glazing is tested to UL 972 or ASTM F122 for physical attack.”
—Valerie Block, senior marketing specialist, DuPont Glass Laminating Solutions

Q: What is the difference in construction between bullet-resistant and intrusion-resistant glazing?

“Bullet-resistant glazing consists of multiple layers of glass and interlayer. All-glass laminates and glass-clad polycarbonate laminates are designed to resist small handguns up to high power rifles. Intrusion-resistant glazing consists of two layers of glass bonded together by an interlayer. The glazing is designed to deter smash-and-grab crime by providing a barrier to entry if breakage occurs.”

Q: Where can I get general information about blast-hazard mitigating glazing?

“The AAMA 510 Voluntary Guide Specification for Blast Hazard Mitigation for Fenestration Systems is intended to establish system performance classifications that can be expected to reduce the hazards resulting from a prescribed blast load. In addition, this guide specification allows manufacturers to voluntarily test products to a standard test size for system evaluation and comparison. However, in most cases, projects of this nature typically employ the services of a specialized security consultant.”

Fire-rated Glazing FAQs

Q: Why isn’t there just one type of fire-rated glass that works everywhere?

“There are purveyors of fire-rated glass that would like architects and glaziers to think that life is simple and one size fits all. However, there are basically two types of fire-rated glazing that serve two distinct needs: fire-protective and fire-resistive. There are several product options within each category. It’s important to consult with more than one firerated glazing manufacturer to make certain you’re getting the full story.”
—Jeff Griffiths, director of business development, Safti First

Q: Why isn’t there a simple chart that can be used to select fire-rated products?

“As we are under a performance-based code, products tested to the proper standards have different listed results, thus it is not feasible to publish a simple chart covering all possible outcomes.”
—Ron Leiseca, eastern regional sales manager, Vetrotech Saint-Gobain

Q: Why does fire-rated glazing cost so much?

“A great deal of costly research and testing goes into developing today’s fire-rated glazing products, because they are being expected to serve multiple purposes such as decorative art glass, hurricane resistance, forcedentry security, ballistic resistance, etc.”

“Many architects and designers also ask about the price of fire-rated glazing, including whether the clear appearance of high-end wireless firerated glass is worth the extra cost. When taking into account aesthetic goals and the incremental cost of fire-rated glazing over a building’s lifetime, we often find that wireless products are well in line with architectural construction costs.”
—Jeff Razwick, president, Technical Glass Products

Q: Can I meet my design goals with fire-rated glazing?

“Increasingly, the answer is ‘yes.’ Today’s clear fire-rated glass allows architects to better match the aesthetic of ordinary window glass, while advanced steel fire-rated frames continue to feature thinner frame profile dimensions to improve visual integration with neighboring curtain walls and windows. Building teams can also select from numerous fire-rated glazing systems, including glass floors and roofs, curtain walls and silicone-glazed curtain walls. Some manufacturers and suppliers can even help design and test custom fire-rated glazing assemblies for projects with unique design and performance needs.”

Q: What type of fire-rated glazing is required under the code?

“It depends on the code edition, but the greatest disconnect is requirement differences between fire-protective and fire-resistive glass.”