Fire Resistance of Building Elements

Classification

Building elements are classified by fire resistance duration (for example 30, 60, 90 or 180 minutes) and by function – load-bearing, separating, or both. Classification relies on standardised tests in which specimens are exposed to a defined temperature curve until load-bearing capacity, integrity or insulation fails. National labelling systems that differ in detail (F90, R90, REI 90) can be mapped to one another through international classification standards.

Relevance to structure and occupancy

The required fire resistance class of an element follows from building height, occupancy, means of escape and compartment size. Later interventions – additional openings, combustible cladding, poorly repaired plaster – can significantly reduce the tested fire resistance without any visible sign of it.

Insurance relevance

For risk assessment, the documented fire resistance of load-bearing and separating elements is a key input for judging fire spread and loss potential. Where verification documentation is missing, particularly in older or repeatedly altered buildings, the actual fire resistance is often uncertain and is assessed conservatively.