brannmotstand

Brannmotstand, or fire resistance, is the ability of a material, component, or structure to withstand fire exposure for a defined period while performing its intended function. It applies to building elements such as walls, floors, and doors, as well as to systems like ductwork and electrical enclosures. Fire resistance is distinct from the fire resistance of people; it concerns containment, protection of occupants, and preservation of structural integrity during a fire.

Fire resistance is typically expressed as a time rating in minutes and is evaluated across several performance criteria. The most common requirements are structural stability (the element maintains load-bearing capacity), integrity (no flame or hot gases pass through), and insulation (the temperature on the non-exposed side remains within limits). If all three are met, the element earns a fire-resistance rating, often denoting durations such as 60 or 120 minutes. In practice, ratings may be presented as R, E, and I values, or as combined EI/R ratings, depending on the standard.

Testing and classification follow standardized fire tests conducted in controlled furnaces. In Europe, tests and classifications are governed by standards such as EN 1363 and EN 13501, with EN 1634-1 covering doors and windows. National building codes translate these ratings into required fire-resistance for different constructions and occupancies.

Maintenance and installation quality strongly affect actual performance. Damaged seals, incomplete joints, moisture, or poor mounting can reduce the effective brannmotstand of a system, underscoring the need for proper design, installation, and inspection.