Flamespread
Flamespread refers to the rate at which a fire propagates along a material surface or through an assembly. It is a key parameter in assessing the fire performance of building materials, textiles, and other products. In safety practice, flame spread is typically quantified using standardized test methods that compare a material’s surface burning characteristics to a reference material, often red oak, and produce a flame spread index (FSI) and a smoke developed index (SDI). Higher FSI values indicate faster flame spread and greater hazard. Many codes classify products into performance groups (for example Class A, B, or C) based on measured FSI and SDI.
Measurement and standards involve methods such as the Steiner tunnel test (NFPA 255, ASTM E84) and ISO
Factors affecting flamespread include material composition (polymers, composites, cellulose), thickness and density, thermal properties, moisture content,
Limitations include the fact that standard tests reflect specific conditions and may not capture all real-world