Designing outside the fire-rated glass box

Fire-rated-glazingIncreased sizes
No longer limited to sequences of borrowed lites and separate transparent fire-rated wall panels, building teams can use fire-rated glass systems to create large glazed areas that extend from floor to ceiling, wall to wall, and across multiple storeys. The flexibility to incorporate extensive glazing that also meets fire-rating requirements provides many benefits.

One advantage of fire-rated glass systems’ versatility and size is the ability to help building teams meet daylighting goals. For example, the Canada Green Building Council’s (CaGBC’s) Leadership in Energy and Environmental Design (LEED) building rating system offers points toward Indoor Environmental Quality (EQ) Credits 8.1 and 8.2, Daylight and Views, when the building team provides occupants with access to natural light within 75 per cent of regularly occupied spaces, and views to outdoor environments within 90 per cent of all regularly occupied areas. Since the line of sight may be drawn through interior glazing, including private offices, classrooms, and other multi-occupant spaces, installing fire-rated curtain walls can help building teams earn points in this category.

Additionally, project teams can incorporate fire-rated glass wall panels throughout school corridors, where illumination and views to the outside can improve working environments for students. Or, they can use fire-rated glass floors to maximize daylight penetration between building levels, allowing light to transfer down into a building’s core.

Fire-resistive-rated glass systems can exceed 25 per cent of the total wall area, allowing for greater design flexibility.
Fire-resistive-rated glass systems can exceed 25 per cent of the total wall area, allowing for greater design flexibility.

Performance benefits
While fire-rated glass systems can advance esthetics, they also help improve fire and life safety. By incorporating fire-resistant glazing—such as glass with intumescent interlayers that turn to foam when exposed to heat—curtain wall, wall, floor, and door systems can block flames, smoke, and heat for up to 120 minutes.

The ability to provide fire resistance in many different glazing applications is critical given today’s open building designs. Large interior spaces, such as those created by a multi-storey atrium, present an opportunity for faster fire growth given the greater air volumes. According to the U.S. National Association of State Fire Marshals (NASFM), this design can create “a lack of compartmentation that would serve to limit fire spread to a smaller area, such as a room or a wing or a floor of a building.” (See Jim Tidwell and Jack Murphy’s “Bridging the Gap: Fire Safety and Green Buildings” (National Association of State Fire Marshals, 2010). The report is available at In comparison, fire-rated glass systems that span across floors or stretch across multiple storeys can provide the feel of an open, light-filled space, while helping reduce the area’s overall volume.

new-GenAnother benefit of using fire-rated glass systems, instead of specifying individual components, is the assurance that the assembly meets code requirements. To ensure adequate protection, a given fire-rated glass assembly—from the frame to the glass, seals, and other components—must provide the same type of fire protection (i.e. ‘fire protection’ to defend against flames and smoke or ‘fire resistance’ to also defend against heat) and carry the minimum fire rating as dictated by code. Given myriad fire-rated glazing products, there is a risk for misapplication if elements are selected separately. Using a systems approach can help guide proper application since manufacturers design and test entire assemblies to meet specific fire and life safety standards.

An important caveat with advanced fire-rated glass systems—such as curtain walls—is to use the specific supplied components, including glass, framing, exterior caps, back framing members, seals, and fire-safing within frames. Swapping out any part of the assembly to achieve a different esthetic or to meet a specific price may compromise the system’s ability to provide the necessary level of fire protection. As a result, the product configurations and details shown in manufacturers’ literature may be the extent of the available standard selection. To achieve a different look or develop a custom solution, one should consult with the manufacturer or supplier during the design process. Some manufacturers can provide design assistance and aid in the development and testing of custom systems.

To support other performance needs, advanced assemblies are available with impact and bullet resistance and can incorporate insulated glass (IG) units to comply with energy requirements.

Fire-rated glass floor systems can provide fire resistance while transmitting light deep into a building’s core.
Fire-rated glass floor systems can provide fire resistance while transmitting light deep into a building’s core.

Project collaboration
Fire-rated glass systems can help building professionals streamline time, work, and costs, particularly if the manufacturer, supplier, or supporting team members are involved early in the design phase. Conversations during the initial stages of a project can help the manufacturer or supplier better understand project goals, from long-term performance to esthetics and cost. This leaves critical time for creative problem-solving and design adjustments, as well as additional testing, when necessary.

While not all fire-rated glass systems require manufacturer or supplier involvement, one should consider early collaboration when:

  • it is the team’s first time using a given fire-rated glass system;
  • a fire-rated curtain wall needs to esthetically match a neighbouring non-fire-rated curtain wall;
  • a multi-storey curtain wall or very large glazed area is required;
  • using an exterior fire-rated glazing system (e.g. curtain wall or roof system);
  • project deadlines are tight; or
  • a custom application may require additional testing.

Beyond streamlining the design process, fire-rated glass systems can help conserve time and costs during installation. Since the manufacturer has selected each component to function well together within an assembly, a systems approach can help prevent re-ordering, project delays, and onsite work-arounds.

Fire-rated glass systems can help transfer light to interior spaces. Photo courtesy Pilkington
Fire-rated glass systems can help transfer light to interior spaces.
Photo courtesy Pilkington

Regarding installation, it is helpful to keep in mind many frames in fire-rated glass systems are shipped as knock-down (K-D) kits ready for onsite assembly. Frame components may be pre-assembled or welded in the factory. However, since pre-assembly is often done on a case-by-case basis, it is important to verify the manufacturer has the resources to assist with this process. In the future, one should expect unitized options to further expedite the installation process.

Moving forward
Designed to meet various needs, fire-rated glass systems are efficient, effective, envelope-pushing products that add value to modern buildings. Incorporating them into building design does not have to be challenging. Project teams can contact a manufacturer or supplier to learn about their latest offerings; partnering with companies helps narrow the research lens by providing information on how fire-rated glass systems solve emerging design challenges, from installation issues to evolving code standards.

Ron Pitts is the Canadian sales manager for Technical Glass Products (TGP), a supplier of fire-rated glass and framing systems, along with specialty architectural glazing products. He has served as a glazing professional in Canada for more than a decade. Pitts can be reached at

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