Fire-rated glazing labels hold many benefits

Relax. Kick back. Enjoy the International Building Code’s new marking system for fire-rated glazing. It’s going to make your life a lot easier. That’s what some people familiar with the new marking system say.

Let’s begin at Undewriters Laboratories. According to Bob Berhinig, principal engineer at UL’s Northbrook, Ill., facility, UL encourages use of the system as a supplement to its classification mark and has included details of the system at the GuideInfo section of its online certification directory. This system marks fire-rated glazing according to fire tests prescribed by the building code. If it is tested to the American Society for Testing Materials ASTM E 119 or UL 263, it qualifies as a fire-rated wall and receives a “W” designation. If it is tested to the National Fire Protection Association’s NFPA 257 or UL 9, including the hose-stream test, it qualifies for use as an “opening” protective, and receives an “OH” designation. If it is tested to NFPA 252 or UL 10C, it qualifies for use in a fire-door assembly and receives a “D” designation. The marking system should eliminate a problem that has plagued the fire-rated glazing industry for years, says Devin Bowman, sales manager for Technical Glass Products in Kirkland, Wash. “There are a lot of products out there being marketed as fire-rated, but they don’t meet code requirements,” he says. “Just because a product is ‘listed’ or ‘labeled’ doesn’t always mean that it meets the prescriptive requirements of the building code. I’ve seen glazing in the field labeled for 45 minutes or more, but it’s tempered and won’t pass the hose-stream test. Code officials sometimes allow it in one-hour corridor openings simply because it has a 45-minute label. The fact that it won’t pass the hose-stream test can easily be overlooked unless the code official goes behind the product’s label to look at its listing. The International Building Code’s marking system should eliminate this problem since it carefully tracks the code’s prescriptive requirements for walls, opening protectives and fire-door assemblies and only code compliant glazing can be marked under it.”

With the new system, building-code officials can determine whether a product is code compliant at a glance. For example, the “OH” marking applicable to products tested to NFPA 257, means that it passes both the fire- and hose-stream parts of the test. If a product is fire tested to NFPA 257 but not tested with the hose stream, there simply is no marking available for such a product under the new system, even if it secures a listing. For that reason, building-code officials should be wary if fire-rated glazing is listed and labeled, but not marked with a “W” an “OH” or a “D.”

While weeding out listed products that don’t meet code requirements, the system allows manufacturers to mark products that exceed code requirements. For example, suppose a glazing assembly is successfully tested to NFPA 257 for 60 minutes and passed the hose-stream test, it would be marked “OH-60,” signaling immediately that it can be used in one-hour corridor openings, even though the code only requires 45-minute rated glazing in one-hour corridors.

Pilkington of the United Kingdom now  marks fire-rated glass using the new system. “Pilkington started marking its products under the new system as soon as the IBC adopted it,” says Bret Penrod, general manager of Pilkington’s North American fire-rated glass operations in Toledo, Ohio. We must avoid confusing code officials and consumers alike. For example, while members of the fire-rated glazing community have recently focused on whether fire-rated glazing does or does not provide protection against radiant heat, the message often causes confusion. For example, in a recent article in Glass Magazine, “Heat transfer and fire-rated glazing,” (February, p. 46), the author compared radiant heat emitted through a variety of different fire-rated glazing. Remarkably, however, the testing used as the basis of the comparison appears to have been the Quincy, Mass.-based National Fire Protection Association’s NFPA 257, not West Conshohocken, Pa.-based ASTM International’s ASTM E119.

According to Section 703 of the IBC, the only permissible test that may be used to determine whether an assembly “prevents or retards the passage of excessive heat” is ASTM E119 or an alternate method based on the fire exposure and acceptance criteria of ASTM E 119. Only glazing materials that limit temperature rise on the non-fire side to 325 degrees Fahrenheit at every thermocouple in the test and an average of 250 degrees F for all thermocouples, qualify for designation as a fire-resistance rated glazing under the IBC.

The IBC’s new marking requirements will clearly distinguish between products that do, and those that do not, meet code requirements for protection against excessive heat transfer. If a product meets ASTM E119, it will be marked “W.” If there’s no “W” marking, the product isn’t fire-resistance rated and doesn’t meet code specifications for limiting heat transfer.

Finally, I spoke with Christopher Young, chief building official for Toledo. His office has fewer officials to inspect more building systems that get more complicated and harder to inspect every year. Anything the code organizations do to make the job of inspecting buildings easier is appreciated and the IBC’s marking system for fire-rated glazing does just that, Young says.