2012 IBC Clarifies Use of Fire Protective and Fire Resistive Glass

The just-published 2012 IBC model building code significantly revises three tables in Chapter 7 in order to clarify requirements and limitations for FRG.  The revised tables do not add new code requirements. Rather, they address confusion about applications, performance and limitations on FRG contained in the 2006 and 2009 editions of the IBC.

Video shows dangers of radiant heat transmission

In order to explain the new 2012 IBC tables, it’s important to understand the difference between fire protective and fire resistive glazing. Each FRG category has its own set of performance features, test standards and allowed applications.  Simply relying on the fire endurance rating (20, 45, 60, 90, 120 and 180 minutes) or whether a product is “thick” or “thin” can lead to faulty specifications and misapplication of the FRG.

Fire protective glass is designed to block smoke and flames, but it cannot block radiant heat.  Fire protective products are subject to the following test standards:  NFPA 252, NFPA 257, UL 9, UL 10B, UL 10C. Fire protective glazing products include: specialty tempered, traditional wired glass, safety wired glass, and ceramics.  While some fire protective products are rated 60 to 180 minutes, they have limits on their use in 1 hour walls and vision panels in doors.  They are prohibited altogether in sidelights, transoms, and windows in 2-hour interior walls.

Fire resistive glass blocks smoke, flames and radiant heat transmission.  Fire resistive products are tested to the following standards:  ASTM E-119, NFPA 251, UL 263. These standards apply to all fire-resistive wall materials where the temperature rise on the non-fire side cannot exceed an average of 250º F.  Fire resistive glass products include fire retardant filled units and multi-laminates.

Because FRG is used in door and wall assemblies, it is important to also consider code requirements for framing.  Simply put, the fire-rated framing requirements must match the glazing requirements.

2012 IBC Chapter 7 tables

In 2009, the International Code Council (ICC) acknowledged that the IBC’s FRG provisions were confusing, so it appointed an ad hoc committee of fire and building officials, test agencies and industry representatives to recommend revisions.  Even though the 2012 IBC does not take effect until accepted by local jurisdictions, the new Chapter 7 tables are helpful in understanding and meeting the glazing code requirements contained in the 2006 and 2009 IBC, as well as NFPA 80 outlined in the 1999 and 2007 NFPA 80 editions.

New FRG Labeling Marking Table 716.3

2012 IBC Table 716.3 designates new marking for fire-rated glazing assemblies that correspond to test standard(s) to which the product was tested.  Click here to download the new table.

2012 Door Assembly Rating Table 716.5 (previously 715.4)

For the first time, the door assembly rating table distinguishes between fire protective and fire resistive glazing.  The 2012 door assembly rating table has a new column that spells out size limits for vision panels, and another column describing where FRG can and cannot be used in sidelites and transoms, and whether or not it needs to be fire resistive glass.  Click here to download Table 716.5 Table. Here are a few highlights.

• Fire protective (e.g., ceramic, wired glass) door vision panels in 2-hour or less fire walls, exit enclosures, exit passageways, and exterior 3- and 2-hour walls are limited to no more than 100 square inches.
• Fire protective (e.g. ceramic, wired glass) products are prohibited in sidelite and transom assemblies in fire walls, interior and exterior 2- and 3-hour walls, and exit enclosures and exit passageway walls.
• No FRG can be used in door vision panels in 3- or 4-hour fire walls

2012 Fire Window Assembly Rating Table 716.6 (previously 715.5)

The 2012 IBC fire window rating table also differentiates between fire protective and fire resistive glazing.  As in the 2012 Door Assembly Rating Table (716.5), the Fire Window Rating Table (716.6) now clarifies where fire protective products are allowed and prohibited, and where fire resistive rated glazing must be used (e.g., 2-hour interior wall openings).  The revised fire window assembly table includes a new column titled “Fire Rated Glazing Marking.”  Click here to download the 2012 IBC Table 716.6.  Highlights include:

• Fire protective (e.g., ceramic, wired glass) products are prohibited from use in 1-hour fire barriers used as exit enclosures or passageways.
• Fire protective (e.g., OH-45) and some fire resistive (e.g., W-60) products are allowed in 1-hour fire barriers used as incidental use areas and mixed occupancies.
• Only fire resistive rated glazing assemblies tested to ASTM E-119 or UL 263 may be used in fire walls and fire barriers rated over 1-hour.

Size of Fire Protective Vision Panels Now Limited to 100 sq inches

Revision in Chapter 7 tables do not change the code;  they simply work to clarify where fire resistive glass must be used instead of fire protective glass.  There is, however, one important change in the new IBC related to glazing in doors.  Previous editions of IBC provided an exception that allowed large fire protective vision panels in fire doors used in exit enclosures and passageways when the building was fully sprinklered.  The new 2012 IBC removes the sprinkler exception.  Here are relevant sections of the 2012 IBC:

Fire-resistance-rated glazing in excess of 100 sq inches in an exit passageway. Warren Co Career Center, Lebanon, OH

716.5.5 Doors in interior exit stairways and ramps and exit passageways. Fire door assemblies in interior exit stairways and rams and exit passageways shall have a maximum transmitted temperature rise of not more than 450ºF (250ºC) above ambient at the end of 30 minutes of standard fire test exposure…

716.5.5.1  Glazing in doors. Fire-protection-rated glazing in excess of 100 square inches (0.065 m2) is not permitted.  Fire-resistance-rated glazing in excess of 100 square inches (0.065 m2) shall be permitted in fire door assemblies when tested as components of the door assemblies, and not as glass lights, and shall have a maximum transmitted temperature rise of 450ºF (250ºC) in accordance with Section 716.5.5.

Building Codes Ban Traditional Wired Glass in Hazardous Locations

Today’s model building codes prohibit the use of “traditional wired” glass in hazardous locations like doors, sidelites, and any location that requires safety.  Wired glass is not safety glass.  The wires actually weaken the glass and wired glass panels can break with as little as 50 ft. lbs. of force, or the force exerted by a small child running into this glazing.

In 1977, traditional wired glass was given an exemption from meeting the CPSC impact safety standard when used in doors, sidelites and other potentially hazardous locations because wired glass manufacturers claimed that they did not have the technology to meet such critical standards.   Twenty-five years later, they still claimed that they could not meet these safety standards.  This all changed when safety wired glass products, such as SaftiFirst’s filmed Superlite I-W, were introduced.

The 2003 IBC removed the exemption for traditional wired glass in educational and athletic facilities and set forth that the federal safety glazing standards applied in those buildings. In the 2004 IBC Supplement and the 2006 IBC code, restrictions were taken one step further.  The result was that traditional wired glass is no longer exempt from meeting safety standards when used in any potentially hazardous location.  This applies to all new construction and in all types of occupancies (see Sec. 2406.1.1 in the 2003 and 2006 IBC). New safety wired glass is economical and meets all the fire protective glazing and safety standards, making it the best value in fire rated glass.