Fire Performance Terms

Expansion Joint– Area of a fire-rated component designed and punched to provide thermal expansion relief for that component. Due to expansion of steel when heated, this expansion control is necessary to keep the fire membrane intact.

Fire Guard Grid– Fire resistance rated grid.

Fire Rated– Refers to the UL fire resistance rating of an assembly.

Fire Resistance– The property of acting as a barrier to fire. Acoustical ceiling systems form a membrane to contain fire within a room. Fire-rated assemblies (including ceiling panels, suspension system, light fixtures and diffusers, and structural components) are given ratings of one, two, three or four hours as tested per ASTM E 119.

Flame Spread Index– A numerical designation, applied to a building material, which is a comparative measure of the ability of the material to resist flaming combustion over its surface; the rate of flame travel, as measured under the applicable ASTM E 84 test, in which a selected species of untreated lumber has a designated value of 100, and noncombustible inorganic reinforced cement board has a value of 0.

Flame Spread Rating– A single number measurement of the flame spread across the surface of a material. Defined by ASTM E 84 commonly known as the 25-foot tunnel test, the number is obtained by comparing with red oak flooring.

The following classes are defined under ASTM E 1264:
FLAME SPREAD SMOKE ASTM E 1264
RATING RATING CLASS
0-25 0-50 A
26-75 — B
76-200 — C

NFPA– Abbr. for the "National Fire Protection Association."

Smoke Developed– The ratio of the smoke emitted by a burning material to
the smoke emitted by the red oak standard material.

Smoke Developed Rating– A relative numerical classification of a building material as determined by an ASTM E 84 test of its surface burning characteristics.