Determining the fire resistance of calcium silicate insulation typically involves evaluating its performance under various fire test standards. These tests assess the insulation’s ability to withstand and limit the spread of fire. Here are two common methods used to determine the fire resistance of calcium silicate insulation:

Fire Endurance Test:

This test measures the insulation’s ability to withstand exposure to fire for a specified period. The most widely recognized fire endurance test standard is the ASTM E119 or the equivalent ISO 834 test. In this test, a specimen of calcium silicate insulation is subjected to controlled heating and monitored for its ability to maintain structural integrity, limit flame spread, and prevent excessive temperature rise on the unexposed side of the specimen. The test duration can vary, but common timeframes include 1 hour, 2 hours, 3 hours, or more, depending on the desired fire rating.

Fire Spread Test:

This test evaluates the insulation’s ability to limit the spread of flame across its surface. The most commonly used test standard for this purpose is the ASTM E84 or the equivalent ISO 5660 test. In this test, a sample of calcium silicate insulation is exposed to a controlled flame, and its flame spread and smoke development characteristics are measured. The results are typically reported as Flame Spread Index (FSI) and Smoke Developed Index (SDI). Lower values indicate better fire resistance and limited flame spread.

It is important to note that fire resistance tests are conducted in controlled laboratory conditions and provide an indication of the insulation’s performance under specific test parameters. The results can help determine the insulation’s suitability for different fire-rated applications. However, the actual fire resistance in real-world scenarios may vary depending on factors such as installation, system configuration, and specific fire conditions.

When assessing the fire resistance of calcium silicate insulation, it is advisable to consult the manufacturer’s technical data, certifications, and test reports. These documents often provide information on fire ratings, test results, and compliance with relevant fire safety standards.