Codes&Regulations

2012 IBC Changes Designed to Make Fire-Rated Glazing Specification Easier

For the first time, the 2012 International Building Code (IBC) has provided a guide advising where to use fire-protective versus fire-resistive glazing in door, window and wall assemblies. The revised Chapter 7 tables now clearly address size limits and appropriate fire-rated glazing (FRG) applications in interior and exterior walls, and exit enclosures and passageways. The new tables help professionals specify where to use fire-protective versus fire-resistive glazing in FRG assemblies, and avoid the misuse of FRG products for end-uses prohibited by the IBC.

These provisions are not new, says Diana San Diego, director of marketing at SAFTI FIRST in San Francisco. Rather, “These are … a clarification of the 2006 and 2009 editions of the IBC,” she explains. “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 provided in the 1999 and 2007 NFPA 80 editions, which are incorporated by reference in the 2012 IBC.

“This will benefit architects immensely as they select the correct fire-rated glass product for their application,” San Diego says. “This helps glaziers, too, because they can have a better understanding of the types of fire-rated glass products that they are installing.”

Devin Bowman, national sales manager at Technical Glass Products in Snoqualmie, Wash., agrees. “For fire-rated glass manufacturers and suppliers, the updated tables help clarify use of materials,” he says. “Depending on how they promoted their products, this could require changes in product literature to be consistent with the latest codes. Manufacturers and suppliers will also need to use the new marking system, but that is a relatively straightforward change.”

Architects, specifiers and glaziers need to be aware of the new fire-rated glass code clarifications as their local jurisdictions adopt them, Bowman says. “As with past codes, there’s often a lag as cities, counties and states switch from their current codes to the latest version, but it’s necessary to know what’s coming.”

He adds, “It’s crucial to pay attention to glass size limits, and to understand where ‘fire-protection’ and ‘fire-resistance’ rated products are allowed. Fire protection glazing defends against the spread of flames and smoke, while fire resistance glazing also blocks heat transfer. This is a critical distinction as the higher level of protection is necessary in certain instances such as exit passageways and for fire walls and fire barriers.”

The same marking system for fire resistance- and fire protection-rated glazing also was included in the 2012 edition of National Fire Protection Association 101, the Life Safety Code, says Thomas S. Zaremba, an industry consultant and partner for Roetzel & Andress in Toledo, Ohio.

There is significant value to having this marking system in place in the codes, Zaremba says. “First, from the perspective of fire-rated glazing manufacturers, the users of fire-rated glazing and the building code officials, it enables all of them to identify directly from the label found on the glazing in the field exactly what fire tests the glass has been subjected to. Second … through the new marking system, the table now shows exactly how fire-rated glazing must be marked in virtually every applications where fire-rated glazing is required.”

Given the increased level of certainty that these provisions provide in assuring that the right fire-rated glazing is being used in the right application, “it should be easier for fire-rated glazing manufacturers to provide the specific applications for their inventories of different types of fire-rated glazings; easier for specifiers to incorporate fire-rated glazing into their construction plans and drawings; easier for installers to identify from the label the right glass for the right applications in the field; and easier for building code officials to determine that the right glass has in fact been installed in the right applications,” Zaremba says.

The new code also simplifies the fire-rated glazing label scheme by reducing the number of markings describing where the glass can be used and which tests it has passed, Bowman says. Marks now include ‘W’ for fire-resistance-rated glazing meeting wall assembly criteria; ‘OH’ for glass meeting fire window assembly criteria, including the hose stream test; ‘D’ for glass meeting fire door assembly criteria; ‘H’ for glass meeting the fire door assembly hose stream test; and ‘T’ for glazing meting temperature rise criteria. As before, a two- or three-digit number shows the fire rating in minutes.

Another important change in the 2012 IBC is clarification in Section 703.4 that automatic sprinklers are not allowed during fire-rated materials testing. Fire ratings for glass and other building materials must be earned based on their own performance, and not as protected by supplemental systems. “This provides an additional margin of safety for building occupants in the event sprinklers fail during a real-world fire,” Bowman says.

At its next meeting, the ICC’s Code Technology Committee is planning to review the changes made to the fire-rated glazing provisions in the 2012 IBC meeting to determine whether any additional changes may be required. “Perhaps using a single table for both fire-rated windows and fire-rated doors in the IBC will be considered for the 2015 edition of the IBC,” Zaremba says.

NFPA 257 Close to Finishing 2012 Updates
The National Fire Protection Association (NFPA) Technical Committee is close to releasing a 2012 edition of NFPA 257, Standard on Fire Test for Window and Glass Block Assemblies. There are really only two substantive changes, says Thomas S. Zaremba, partner at Roetzel & Andress in Toledo, Ohio. The first modifies section 4.1.2, which dealt with furnace temperature at the start of the test.The 2007 edition of the standard required the temperature inside the furnace at the beginning of the test to be ambient. That has been changed because the temperature of a cold furnace at the start of a fire test is not significant, Zaremba explains.

“What is significant is the temperature of the test laboratory where the specimens are located before the test,” he says. Accordingly, this section will now read: “At the start of the fire test, the ambient laboratory air temperature shall be in the range between 50-90 degrees F.”

The second substantive change will delete section 4.3.4 from the 2012 edition. That section addresses “neutral pressure” testing, and since all codes now require testing under positive pressure, this section is no longer necessary.
www.nfpa.org/257

New ASTM Standard for Glass and Glazing Systems Published
ASTM F2912-11, Standard Specification for Glazing and Glazing Systems Subject to Airblast Loadings, was published August 11. The specification covers exterior windows, glazed curtainwalls, glazing panels in doors and other glazed protective systems used in buildings that may be subjected to intentional or accidental explosions.

“ASTM F 2912 was created to provide guidance to those interested in incorporating bomb-blast resistance into their facilities when they don’t have the benefit of a government specified mandate for performance,” says Julia Schimmelpenningh, global applications manager of advanced interlayers, a division of Solutia Inc. in Springfield, Mass. “It is structured to ensure the critical parameters for blast design are communicated in the specification: load, duration, protection/hazard level, this ensures a more rapid translation of product configurations for quotes and delivery. The publication of this specification is hoped to demystify blast resistance to some extent and make it a much more common consideration for commercial and industrial facilities.”

The specification addresses only glazing and glazing systems, and does not address the structural integrity and functionality of door assemblies. It assumes that the designer has verified that other structural elements have been adequately designed to resist the anticipated air-blast pressures.

The specification was designed for all glazing, glazing systems and glazing retrofit systems. It does not determine the assessment of a facility nor acceptable hazard ratings. Threat and risk assessment shall have already been performed and the acceptable hazard rating defined.

The specification will be under a 5-year review cycle.
www.astm.org

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