Fire-rated glass codes update
When it comes to fire-rated glazing codes, architects need to familiarize themselves with the revised Chapter 7 tables in the 2012 International Building Code: tables 716.3, 716.5 and 716.6. These tables are a significant step towards minimizing misapplications, because, for the first time, the IBC recognizes the difference between fire protective versus fire resistive glazing, and clearly outlines their allowed applications and limitations.
It's important to note that these are not new code requirements, but rather a clarification of the 2006 and 2009 editions of the IBC. Even though the new tables will not be adopted locally until jurisdictions accept the 2012 IBC, they are useful today in understanding the 2006 and 2009 IBC glazing requirements. The requirements contained in the new tables have been in effect since the 2006 IBC, and conform to what NFPA 80 from the National Fire Protection Association provided in the 1999 and 2007 NFPA 80 editions, which are incorporated by reference in the 2012 IBC.
Also, previous editions of the code provided for an exception that allowed larger fire protective vision panels in fire doors used in exit enclosures and passageways when the building was fully sprinklered. The new 2012 IBC removes that sprinkler exception and now reads as follows:
7188.8.131.52 Glazing In doors. Fire protection rated glazing in excess of 100 square inches is not permitted. Fire resistance rated glazing in excess of 100 square inches shall be permitted in fire door assemblies when tested as components of the door assemblies, and not as glass lites, and shall have the maximum end temperature rise of 450 degrees Fahrenheit in accordance with 716.5.5.
Section 7184.108.40.206 makes it clear that fire protective glazing cannot exceed 100 square inches. 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 minutes of fire exposure.
Lastly, it is important for design professionals to understand that the listing agencies, such as Underwriters Laboratories and Intertek/Warnock-Hersey, do not list fire-rated glass products in accordance with the codes or limitations on their use. Instead, test agencies simply report the sizes and types of assemblies in which a product has been tested. Accordingly, listings cannot be relied on for determining accepted code applications.