What is the primary purpose of this test?

To determine the fire-resistance rating (in minutes) of a firestop system when exposed to a standard fire, assessing its ability to prevent the passage of fire and hot gases.

What constitutes an 'Integrity' failure?

Failure occurs if a cotton pad on the unexposed face ignites, sustained flaming of over 10 seconds occurs, or if specific sized gap gauges (6mm or 25mm) can penetrate the specimen (Clause 7.2).

What constitutes an 'Insulation' failure?

Failure occurs if the average temperature on the unexposed face rises by more than 140°C, or the maximum temperature at any point rises by more than 180°C above the initial ambient temperature (Clause 7.3).

What fire exposure condition is used in the test?

The test uses the standard time-temperature curve and furnace conditions as specified in IS 3809 (Clause 6.1).

IS 12458

: 1988

Method of fire resistance test of firestops

CurrentSpecializedTesting MethodBIMFire Safety · Fire Safety

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This standard outlines the method for conducting fire resistance tests on firestop systems used to seal openings and penetrations in fire-rated walls and floors. It specifies the test furnace conditions, specimen preparation, test procedure, and the criteria for failure based on integrity and insulation performance.

Method of fire resistance test of firestops

Quick Reference Values

Insulation Failure (Average Temp Rise)140 °C

Insulation Failure (Max Temp Rise)180 °C

Integrity Failure (Gap Gauge for cracks)6 mm

Integrity Failure (Gap Gauge for openings)25 mm

Furnace Pressure at mid-height (or higher)+10 ± 2 Pa

Sustained Flaming for Integrity Failure10 seconds

Practical Notes

This test evaluates a complete 'system' (firestop material, penetrating service, and surrounding structure), not just the firestop material in isolation.

The test result is a fire resistance rating in minutes (e.g., 60, 120), which determines the suitability of the firestop for a specific fire compartment wall/floor rating.

Correct furnace pressure control is critical as it simulates the forces that push hot gases and flames through any weaknesses in the firestop.