Exterior Glass Walls, Windows & Doors – Commercial & Residential Glass | Article

When designing your exterior walls, windows, and doors, you’ll consider what material to use that’s both effective and safe. You may be wondering how to balance your aesthetic design desires with your safety and security needs. The choices you make for your exterior glass walls can define how your building, whether commercial or residential, will be perceived and protected.

Many designers choose glass for exterior applications. Exterior glass walls, windows, and doors are not only aesthetically beautiful but can be crafted for the safety of building occupants and property with fire-rated glass. Add fire rated exterior glass to doors, entryways, storefronts, windows, and more for a safe and beautiful finish.

Exterior Glass Design Aesthetic

The exterior design of your building is important. You want a beautiful façade that captures attention and represents your aesthetic in property line or lot line situations. Utilizing fire-rated exterior glass gives your building a clean, open, fresh look that is both inviting and elegant while meeting the requirements of the code.

Fire-rated glass allows light to pass through from one area to another, blending natural and artificial lighting into spaces deep within the building. You can save energy and create a sense of openness throughout your space. Exterior glass can be used throughout your building with glass doors, glass panels, entryways and more. Typical size or application limitations regardless of the fire separation distance don’t apply to ASTM E119 / UL 263 rated fire resistive glazing, so designers can use fire resistive glazing where exterior openings are not permitted or limited in size. With fire-rated exterior glass, you don’t have to compromise safety for aesthetics.

Fire-Rated Glass – Safety Benefits

Fire-rated exterior glass also provides immense safety benefits. SAFTI FIRST® offers a variety of fire-rated glass that’s focused on your safety. You’ll be able to choose between fire resistive or fire-protective glazing for your exterior glass wall, window or door to get a  solution that’s custom for your building’s needs.

Fire-protective glass, like SuperClear 45-HS-LI, is tested to NFPA 252, NFPA 257, UL 9 and UL 10C. It is designed to compartmentalize smoke and flames and is subject to application, area, and size limitations under the IBC. Fire-protective glass is typically used in door assemblies and windows/openings up to 45 minutes and cannot exceed 25% of the total wall area because it does not block radiant heat transmission.

Fire-resistive  glass, like SuperLite II-XL 120, is not limited in application or size. This type of fire-rated glazing is tested to ASTM E119 or UL 263 and compartmentalizes smoke and flames and blocks the transmission of dangerous levels of radiant heat through the glazing. As a result, it can be used in wall and door applications 60 minutes and above without the size limitations that apply to fire-protective glass.

Explaining Lot Line Requirements

The fire rating for exterior walls is based on construction type, occupancy and fire separation distance as defined in Section 6 of the IBC. These fire resistance requirements range from no required rating to 3 hours.

Once the fire separation distance has been established, Table 705.8 in the IBC lay out the percentage of protected and unprotected openings and size limits allowed in exterior walls. When allowed, the codes distinguish between openings that are “unprotected” (no fire rating) with or without sprinklers, and “protected” (such as fire protective glazing in openings tested to NFPA 257 / UL 9).

Fire protective glass tested to NFPA 257 / UL 9 are either limited in size or prohibited altogether depending on the fire separation distance. Generally speaking, as the fire separation distance increases, the allowable opening area and the percentage of allowable fire protective openings increases.

However, these limitations do not apply to fire resistive glass tested to the more stringent ASTM E119 / UL 263 standard, which requires limiting the temperature rise to less than 250º F above ambient on the non-fire side. Designers can use fire resistive glass in areas where exterior openings are not permitted or limited in size per IBC Table 705.8.  By using fire resistive glass, designers don’t have to sacrifice expansive clear views and abundant natural light in order to meet code requirements.

Protection Against Other Threats

Advanced fire-rated glazing systems can multi-task to provide additional protection against various environmental and man-made threats. Fire-rated glazing manufacturers have tested and listed systems that also meet:

• Florida Product Approval, Texas Department of Insurance and UL certifications for hurricane;
• Up to UL 752 Level 8 for ballistic;
• U.S. Department of Defense Minimum Antiterrorism Standards for blast;
• ASTM F-1915 Grade 1-4 for forced entry.

Commercial and Residential Use of Exterior Glass

When utilizing fire-rated exterior glass, you don’t have to sacrifice aesthetics for safety. There are many applications of exterior glass throughout both commercial and residential spaces that enhance your design aesthetic, increase safety, support energy efficiency, and other performance requirements.

Select from a variety of fire-rated exterior glass products from SAFTI FIRST® to enhance your building’s safety and design appeal today.

Fire-Protective Glass

• SuperLite I
• SuperClear 45-HS
• SuperClear 45-HS-LI
• SuperLite I-XL
• SuperLite I-XL IGU
• SuperLite X-45/60/90

Fire-Resistive Glass

• SuperLite II-XL 45
• SuperLite II-XL 60
• SuperLite II-XL 90
• SuperLite II-XL 120
• SuperLite II-XLM 60
• SuperLite II-XLM 120
• SuperLite II-XLB 60
• SuperLite II-XLB 120
• SuperSecure II-XLS 45 to 120

Chapter 7 of the IBC provides guidelines on where fire rated glass is allowed or limited based on the application.  However, it up to the individual states to determine which version of the IBC they are adopting.  As of May 2020, Texas is the only state that has not officially adopted the 2012/2015/2018 IBC. However, local jurisdictions in Texas are authorized by state law to adopt later editions of the IBC.

To learn what version of the IBC your state is adopting to download the corresponding IBC Chapter 7 fire rated glass guide, click here.

Fire Rated Glass FAQs

Here are some of the most frequently asked questions on fire rated glass:

What are the code requirements in a 1-hour exit corridor?

The codes allow 20-minute fire doors with 20-minute vision panels without hose stream in 1-hour exit corridors. Sidelites and transoms around the door in a 1-hour exit corridor require a 45-minute fire rating with hose stream. Fire windows are required to be rated 45-minutes, and are limited to under 25% of the total wall area. If more window glazing is desired, fire-resistive glazing assemblies rated equal to the wall must be used.

What are the code requirements for 1-and 2-hour exit/stairwell enclosures?

The codes specify extra fire protection levels for fire doors and glazing products in exit enclosures and passageways, in order to protect occupants exiting a burning building from smoke, flames and exposure to dangerous radiant heat. Fire protective glazing in temperature rise 60-or 90-minute temperature rise doors in an exit enclosure or passageway is limited to 100 sq inches. Larger door vision panels, sidelites, transoms and wall glazing surrounding the door must be fire resistive.

In a sprinklered building, can you increase the size of the door vision panel in an interior exit/stairwell enclosure?

No. the maximum allowable vision panel in a 60-or 90-minute, temperature rise door in an interior exit enclosure or passageway is 100 sq inches, regardless of whether the building is fully sprinklered or not. The only way to increase the size of a vision panel in a 60-or 90-minute door in an exit/stairwell enclosure is to use fire resistive glazing.

What are the code requirements for fire rated framing?

Because fire rated glazing is used in door and wall assemblies, code requirements for framing must also be considered. Simply put, the fire rated framing requirements must match the glazing requirements in order for the assembly to fully meet the code requirements. Hollow metal framing is fire protective, not fire resistive, so where codes require fire resistive glazing, the framing must also be fire resistive, and the entire assembly must meet the same rating requirement as the wall.

For more resources on fire rated glazing code or applications, click here.

About SAFTI FIRST®

SAFTI FIRST® is the leading vertically integrated, single source, USA-manufacturer of advanced fire rated glass and framing systems for over 40 years. Our products are listed and labeled by UL and Intertek up to 2 hours and are used in fire rated doors, windows, walls, storefronts, curtain walls and floors.  Our products can be further enhanced to provide additional protection against hurricane, blast, ballistic, forced entry, attack, and other performance requirements.  Decorative and energy efficient make-ups are also available, with SAFTI FIRST® having approved fire rated glazing and framing components in the NFRC CMAST database.