noncombustible

Noncombustible refers to materials that do not ignite or contribute to a flame under standard fire exposure. In building codes, a material is considered noncombustible if it passes certain tests that simulate fire conditions. In the United States, ASTM E136 is commonly used; in Europe, EN 13501-1 provides noncombustible classifications such as A1/A2. These classifications focus on whether the material itself can ignite and sustain flame, not on all aspects of fire performance.

Role in construction: Using noncombustible materials reduces fuel load and hampers flame spread, especially in walls, floors, and façades. They are often specified for exterior cladding, curtain walls, and fire-rated assemblies, as well as for structural elements in high-rise buildings. Noncombustible does not imply that the material is fireproof; high-temperature exposure can cause heat damage or loss of strength in metal components or spalling in concrete.

Examples: Concrete, brick, stone, ceramic tiles, glass, most metals (steel, aluminum), gypsum-based boards, cementitious panels, mineral wool insulation. Some composites and coatings may be considered noncombustible, depending on the classification standards used.