brandmotstånd

Brandmotstånd, or fire resistance, is the ability of building materials and assemblies to withstand a fire for a defined period while maintaining essential functions such as structural stability, limit of heat transfer, and compartmentation to slow spread. It applies to components like walls and floors, doors and windows, insulation systems, cables, and other engineered assemblies.

Fire resistance is expressed as a time-based rating, typically in minutes (for example 30, 60, 90, 120 minutes). A rated element is expected to sustain its critical functions during exposure to defined fire conditions for that period. Ratings often refer to criteria such as maintaining load-bearing capacity (structural integrity) and limiting temperature rise or flame passage. Some assessments also consider insulation performance to reduce heat transfer to the protected side.

Testing and certification: Fire resistance is determined in standardized fire tests that simulate a fire exposure, commonly a furnace test with a specified temperature-time curve. Test results are reported as a fire resistance rating and are used to guide construction design and compliance with codes. In Europe, tests and classifications are governed by standards such as EN 1363-1/2 and EN 13501-1/2 for reaction to fire; in other regions, ASTM E119 or NFPA 251 are used.

Standards and usage: Jurisdictions require certain fire resistance ratings for building elements depending on location, occupancy, and risk. The installation must meet the specified assembly details, joints, and penetration sealing; partial or poor installations can reduce effective performance.