The ASTM E 119 and UL 263 tests evaluate the ability of an
assembly to contain a fire, maintain its structural stability, or
both, over the period of time for which it will be rated. The tests
measure and evaluate heat transfer (temperature rise) through
membrane elements that protect structural framing to help
ensure the assembly can serve its purpose and also measure heat
transfer through the entire thickness of the assembly to ensure that
hot-surface ignition cannot occur on the protected side. These tests
are conducted using the time-temperature curve shown in Figure
1. The temperatures used in the test standard are not intended to
be indicative of any specific fire type but are intended to provide a
consistent reproducible means so that various building elements,
components and assemblies can have their performance evaluated
and compared to both the test and to each other.
Figure 1