Fire Rated Glass FAQ and Fire Codes

When is safety glass required?

Impact resistant safety glass is required in hazardous locations which is defined as being in a door, within 24" of a door, within 18" of the floor per  IBC 2406.

What is the maximum fire rating and maximum size?

See chart below

Doors up to 60 minute have a max size of 36" x 89" (non-temp rise)

Doors up to 90 minute have a max size of 36" x 56-1/2" (non-temp rise)

Doors up to 180 minute and temp rise doors have a max size of 100 square inches

Glass in walls is slightly more complicated - It has a maximum allowable exposed area (clear view), along with a maximum sheet size, and a maximum width and maximum height.

Walls up to 60 minute have a max exposed glass area of 3,325 square inches (23 square feet). The max sheet size is 96" x 48".

Walls up to 90 minute have a max exposed glass area of 2,627 square inches (18.24 square feet). The max allowable width or height cannot exceed 56-1/2". And the max sheet size is 96" x 48".

What codes does this fire rated glass meet?

See chart below

UL 9, UL 10B, UL 10C, NFPA 80,  NFPA 257, and Hose Stream.

If safety rated is selected, then it meets all the codes above and NFPA 252, ANSI Z97.1 CPSC 16 CFR 1201 CAT II.

Is this glass labeled with the fire rating?

Yes, per IBC 703.6, fire rated glass must be permanently labeled with the fire rating in accordance with Table 716.3

What is Fire-Rated Glass?

Fire-rated glass is specially designed to prevent the spread of flames and smoke, and depending on product makeup, the transfer of radiant and conductive heat. The product’s rating, from 20 minutes to three hours, is determined through rigorous testing conducted at independent laboratories such as

Underwriters Laboratories, Inc.® (UL). The rating reflects the amount of time the material has been tested to remain in place to help stop the spread of fire and smoke. This is called “compartmentation.” The introduction of glass ceramic products for fire-rated applications in the 1980s took compartmentation to the next level, creating many new opportunities and uses. These wirefree products look similar to ordinary window glass, providing great design flexibility. As with wired glass, fire-rated

glass ceramics can withstand the thermal shock of water from sprinklers or fire hoses. Where impact safety is required, they are available with up to Category II impact-safety ratings (CPSC 16CFR 1201) (See safety glazing sidebar). This is the highest standard impact-safety rating available, and indicates the glass can safely withstand an impact similar to that of a full-grown, fast-moving adult. Some other important fire-rated glass ceramic considerations include:

• The products can be cut and handled like regular float glass; allowing local availability and processing from certified distributors;

• The products can be insulated when necessary, providing daily thermal efficiency as well as fire-rated

performance;

• While ordinary glass breaks at 250 degrees F, glass ceramic maintains its stability where temperatures may exceed 1,600 degrees F;

• Fire-rated glass ceramic passes fire and hose stream tests without wires; and

• These products look like typical float glass; and can be used in much larger sizes than traditional wired glass.

What's the difference between Fire Protective and Fire Resistive

Fire-rated glass and frames can be described as either fire-protective or fire-resistive. While fire-protective products stop flames and smoke, they are not a barrier to radiant and conductive heat. This includes products, such as traditional wired glass, glass ceramic, hollow metal steel frames, etc. These applications typically may not exceed 25 percent of the aggregate length of the wall and may not exceed 120 square feet per opening. In addition, products with fire-ratings over 20 minutes must pass the required hose stream test. Fire-resistive products, including both glass and frames, are designed to stop flames, smoke and radiant and conductive heat transfer. These are tested to fire resistance standards for wall construction and therefore classified as a wall rather than an opening (i.e., window). Both the glass and frames must block the passage of radiant heat. Fire-resistive framing is rated up to 120 minutes and is required as an assembly, meaning both glass and framing. It’s not only fire-rated, but is also hose-stream tested, a barrier to heat and positive pressure tested. Several framing options are available including filled profile systems, aluminum-clad systems, butt-glazed systems, and various curtain wall

systems, such as structural glazing, among others. In addition, fire-rated products can be used in exterior applications, as well as glass flooring, among other specialty applications. Due to these systems being tested to the same fire test standards as wall construction, they are not limited to the total area or individual opening size limitations of fire-protective assemblies.