Firerating

Firerating, often written as fire rating, is a designation applied to building components or products that indicates how long they can withstand exposure to fire. The rating is based on standardized fire tests and reflects the component’s ability to maintain structural integrity, resist smoke, and limit heat transfer during a fire. Firerating is used in design, construction, and safety planning to meet regulatory requirements and performance criteria in different occupancies and hazard levels.

The determination of firerating follows recognized test methods appropriate to the jurisdiction and product type. In North America, ratings are typically expressed as a time duration, such as 1-hour or 2-hour fire resistance for assemblies like walls, floors, or doors. In Europe and many other regions, classifications often use terminology like REI or EI, where R indicates load-bearing capacity, E indicates resistance to flame passage, and I indicates insulation performance, with a time component (for example, EI 120 minutes). The specific standards cited may include ASTM E119 or UL 263 in the United States, and EN 13501-2 or related standards elsewhere.

Firerating applies to assemblies rather than individual materials alone. It covers elements such as walls, floors, ceilings, doors, glazing, and coatings, and it assumes proper installation and condition as tested. The rating informs code compliance, insurance considerations, and product selection, but real-world performance also depends on correct installation, maintenance, and potential aging or damage that can compromise the rating.