What Integrity (E) and Insulation (I) mean, how EI60 differs from E60, and which rating your project needs under the NCC 2022.
EI60 is a fire-resistance rating derived from AS1530.4 (Methods for fire tests on building materials, components and structures). The rating is set by the NCC 2022 (National Construction Code) and tells you two things about a glazing assembly:
When you see "EI60" on a test report, it means the glazing satisfies both criteria simultaneously over a 60-minute fire test. This is the most common rating specified for Australian commercial and residential fire-rated glazing.
The Integrity criterion measures how long the glass assembly can prevent flames and hot gases from passing through. During the AS1530.4 test, the specimen is exposed to a standard time-temperature curve (reaching 945°C at 60 minutes). Integrity failure occurs when:
Standard toughened glass can achieve integrity for a limited time, but once it reaches its thermal limit, it cracks and falls out of the frame — immediately failing integrity.
The Insulation criterion measures how much heat transmits through the glazing. Temperature sensors on the unexposed face record two limits:
Insulation is the harder criterion to meet. Standard toughened glass passes heat almost instantly — it fails insulation within minutes. To achieve I, you need special interlayers, gel-filled systems, or multi-layer glazing that blocks radiant heat.
Key distinction: E60 glass stops flames for 60 minutes but lets dangerous levels of radiant heat through. EI60 glass stops both flames and heat. For most occupied buildings in Australia, the NCC requires insulation-rated glazing for fire-resistance levels above 30 minutes.
| Property | E60 | EI60 |
|---|---|---|
| Flame penetration resistance | 60 min | 60 min |
| Radiant heat blocking | No | 60 min |
| Non-fire side temp limit | Not measured | ≤140°C avg / ≤180°C peak |
| Typical glass type | Toughened + wire | Multi-layer with intumescent interlayers |
| NCC 2022 occupancy | Sprinkler-protected, non-habitable | General habitable areas, egress paths |
| Cost per m² (approx.) | Lower | Higher (20-40% premium) |
E60 is acceptable only in very limited scenarios under the NCC 2022:
The vast majority of Australian fire-glazing specifications call for EI60 or higher. You need insulation-rated glass when:
The test specimen (glass + frame assembly) is mounted vertically in a furnace. Furnace temperature follows the standard time-temperature curve:
| Time (min) | Furnace temp (°C) |
|---|---|
| 5 | 576 |
| 10 | 704 |
| 30 | 871 |
| 60 | 962 |
| 90 | 1020 |
| 120 | 1055 |
During the test, integrity is monitored visually and with the gap gauge. Insulation is recorded by thermocouples on the unexposed face. The assembly passes if both criteria hold for the full 60 minutes.
For projects requiring longer fire resistance, PyroSpec supplies EI90 and EI120 assemblies using advanced multi-layer glazing systems. Your choice depends on:
For virtually all Australian building projects where fire-rated glazing is required, specify EI60 as the minimum. Move to EI90 or EI120 if the FRL requires it. Reserve E60 only for sprinkler-protected non-habitable spaces where a fire engineer has specifically confirmed it's acceptable.