Fire rating classification under EN 13501-1 is one of the most frequently misunderstood raised floor specifications, yet it directly affects building code compliance, insurance premiums, and occupant safety. The three main classifications A1, A2, and B represent significantly different levels of combustibility that correspond to different core materials and panel constructions. Understanding which class is required for each building type and how to verify compliance through independent test documentation is essential for architects and specifiers who may work with raised floor systems only periodically but must ensure their specifications meet all applicable fire safety regulations. The SC Raised floor system panels with steel-cementitious core achieve A1 classification for maximum fire safety in critical infrastructure.
A1 A2 and B Classification Explained
A1 classification requires that the material makes no contribution to fire at any stage of a fully developed fire, including zero contribution to heat release, flame spread, or smoke production. Only fully mineral-based core materials such as calcium sulfate, steel-cementitious composites, and cement fiber with steel reinforcement can achieve A1 classification. A2 materials offer very limited contribution to fire with heat release values below ten megajoules per kilogram and total heat release below fifty megajoules per kilogram. B-rated materials provide limited contribution to fire but may include organic components that burn under sustained exposure, such as wood particleboard cores with fire-retardant treatments. HUIYA salt spray test verified metal components complement A1-rated panels by ensuring that pedestals, stringers, and edge trim also meet the non-combustible requirements specified by building codes and insurance underwriters.
The raised floor systems market offers products across all three fire classification categories, with price generally decreasing from A1 through B. An A1-rated calcium sulfate panel may cost fifteen to twenty-five percent more than an equivalent B-rated wood-core panel, but this premium is justified in applications where fire safety is the primary concern. For multi-story buildings where the raised floor creates a concealed void space that can facilitate fire spread between floors, local building codes may specifically require A1-rated panels in all areas regardless of occupancy type. Insurance underwriters are increasingly mandating A1 classification for raised floors in facilities with high-value contents, and specifying below the insurer’s requirement can result in significantly higher premiums or coverage exclusions that offset any initial material cost savings.
The image below shows a fire resistance testing setup for raised floor panels: 
For project teams specifying raised floors across multiple international markets, understanding regional fire classification variations is essential for compliant specifications. The European EN 13501-1 system is adopted in most markets worldwide, but some countries maintain local classification systems that differ in testing methodology or classification thresholds. The Japanese JIS A 1450 standard, for example, includes fire resistance testing as part of a comprehensive performance evaluation that also covers load deflection and impact sound insulation. Products carrying both European A1 classification and JIS certification provide the broadest acceptance across jurisdictions and simplify procurement for international construction firms managing projects in diverse regulatory environments. Specifying dual-certified products eliminates the need for separate product lines and reduces the risk of specification rejection during local building permit review processes.