FIRE PROTECTIVE GLASS REQUESTS SPARK SAFETY CONCERNS
Here at VT, safety has always been a top concern and with recent requests for fire protective glass larger than 100 square inches in a 60-90 minute fire door, we thought we should address an important issue that we continue to see in the industry.
Before 2012, the International Building Code (IBC) provided for an exception that allowed fire protective glazing (such as ceramics and wired glass) to exceed 100 square inches in door vision panels in 60-90 minute exit enclosure and passageway doors provided that building was fully sprinklered.
Hazards in radiant heat transmission led the International Code Council (ICC) to the decision of eliminating the sprinkler exception. The reason was because the presence of sprinklers in a building does not eliminate the life safety and fire spread hazard posed by the unrestricted transmission of radiant heat flux through large sizes of fire protective glazing in door vision panels in 60-90 minute doors, especially when these doors are used to protect exit enclosures and exit passageways deemed essential for life safety.
The IBC number 7126.96.36.199 glazing in doors, states that fire protection rated glazing in excess of 100 square inches (0.065m2) is not permitted. Fire resistance rated glazing in excess of 100 square inches (0.065m2) shall be permitted in fire door assemblies when tested as components of the door assemblies, and not as glass lights, and shall have the maximum end temperature rise of 450 degrees F (250 degrees C) in accordance with IBC number 716.5.5.
This makes it very clear that fire protective glazing such as safety ceramics and wired glass cannot exceed 100 square inches, even when used in a non-temperature rise door in a fully sprinklered building. It further states that fire resistive glazing is allowed in excess of 100 square inches as long as it limits the temperature rise to 450 degrees F above ambient after 30 min. of fire exposure. Therefore, the code clarifies that fire protective glazing is limited to 100 square inches regardless of whether the building is fully sprinklered or not.
Saftifirst published an excellent article regarding this topic. To view the article, please visit the following link:http://safti.com/articles/limitations/