Fire-Rated Glass
Advances in fire-rated glass have created more options for protection from the effects of fire. ITI Glass sources several transparent fire-rated glass products.
During a fire, heat transfer can cause flames to quickly spread throughout a building. A well-selected integration of fire-rated building products can effectively contain the effects of fire, resulting in greater protection of a building's inhabitants and reducing structural damage.
What is Fire-Rated Glass?
Stress caused by uneven heating on regular annealed glass results in quick breakage as glass expands and contracts with temperature changes. Fire-rated glass is engineered to be insensitive to high temperatures and is tested to meet a specific minute rating that represents its ability to withstand breakage during a fire. Fire glass is typically rated between 20 and 180 minutes.
Fire-Rated Glass Types
All fire-rated glass resists breakage during exposure to high heat for a specified amount of time. However, fire-rated glass types offer differing protections from the effects of fire, including blocking radiant heat transfer and withstanding breakage under hose stream testing.
Application for each fire-rated glass type depends on the project’s specific requirements, based on building and safety codes.
Fire Resistive
Fire resistive fire-rated glass contains radiant heat, smoke and flames during a fire. This type provides the most protection from the effects of fire.
Fire resistive glass is used in applications that require protection for longer than 45 minutes. Some fire resistive products are rated to 120 minutes.
Heat Reflective
Heat reflective fire-rated glass provides partial protection from the effects of fire by reflecting radiant heat back to its source. Because heat reflective glass breaks under hose stream testing, it must be specialty tempered for fire-rated applications.
In minutes, radiant heat from fire can ignite materials on the non-fire side of a conventional window.
Fire Protective
Fire protective fire-rated glass contains smoke and flames by resisting breakage during a fire. Fire protective glass does not prevent radiant heat transfer, which can cause objects on the non-fire side to ignite.
Fire protective glass is generally used in applications that require up to 45 minutes of protection. (However, it can be specified in fire doors for longer than 45 minutes if the application area is smaller than 100 square inches.)
Wired Glass vs. Fire-Rated Glass
Traditional wired glass is not classified as a safety glazing material by the Consumer Product Safety Commission (CPSC). Because the product is two times weaker than annealed glass, it breaks easily under stress from high heat or impact and is not rated to withstand the effects of fire.
Wired glass has an inner layer of wire mesh that holds glass in place when broken. Because of this feature, the product was given an exemption from safety standards in public buildings as a cost-effective alternative to safety glazings. More recently, the 2003 IBC and NFPA 5000 building codes eliminated the use of traditional wired glass in the construction of all educational and athletic facilities as advances in fire-rated glazing technology have produced new generations of safer, more affordable fire-rated glazings. Transparent fire-rated glass can be 10 times stronger than traditional wired glass and provides a much safer environment for building occupants.
