Fire Rated Glass for 45 Minute Applications

Testing and Code Requirements

45-minute fire rated glass is used in fire protective doors, sidelites, transoms and openings that are tested to the following standards:

  • NFPA 252, Standard Methods of Fire Tests of Door Assemblies
  • NFPA 257, Standard on Fire Tests for Window and Glass Block Assemblies
  • UL 9, Standard for Safety Fire Tests of Window Assemblies
  • UL 10B, Fire Tests of Door Assemblies
  • UL 10C, Positive Pressure Fire Tests of Door Assemblies

Chapter 7 of the International Business Code (IBC) includes Tables 716.5 and 716.6 for guidance on where 45 minute fire rated glazing is allowed. The IBC limits the use of 45-minute glazing to 25% of the wall area because it blocks smoke and flames but not radiant heat. Read more…

Comparing 45 Minute Product Options

There are many product options for 45 minute fire rated glazing. All meet the same testing and code requirements, but they vary widely in performance, appearance and cost.

Wired glass. Forty years ago, this was the only fire rated glass option available, which is why you see so much of it. Unfortunately, the unsightly wires weaken the glass and it breaks easily with minimal human contact. It also fails to block radiant heat.

Glass Ceramic. The desire for wire free glass led to ceramics. Like wired glass, ceramic also breaks easily and must be filmed or laminated to meet safety requirements in hazardous locations. Ceramics also transmit radiant heat, has a tint that cannot be removed, and is quite expensive.

SuperLite II-XL 45. This readily available wire- and tint-free 45-minute glazing option meets all fire- and safety-requirements at a fraction of the cost of ceramic. Unlike either wired glass or ceramic, SuperLite II-XL 45 meets Cat I and Cat II impact safety requirements and provides full radiant heat protection. So, it can be used in large vision door panels and expansive sidelites and transoms as seen in the example below.