Factors that may affect the structural integrity of a building include:
- The age, design and condition of the building
- Structural materials and construction methods
- Unusual designs such as air-supported structures
- Existence of fire protection – active and passive
- Substandard or unregulated construction or modification
- Fire loading to structural elements
- Fire conditions on arrival; size, severity, location and number of fire-breached compartments
- Backdraught, flashover or explosions
- Engineered timber and connections, such as truss joists and nail plates
- Applied load increase as a result of fire water loading
- Cutting structural elements for firefighting operations
- Severe weather conditions, such as flooding, heavy snow or high winds
Potential signs of collapse may include the following:
- Cracks in walls
- Sagging floors or floors deflecting from wall
- Displaced columns
- Cracking or dropping arches
- Bulging walls
- Buckling columns or beams
- Water or smoke that pushes through what appears to be a solid masonry wall
- Unusual noises coming from the building structure
For more information see hazards:
- Impact of fire or firefighting on structural elements or structural frames
- Impact of fire or firefighting on structural materials
Preventative action can minimise the potential impact of a fire on the inherent structural stability of a building. This may include cutting away and opening up to expose concealed areas, in order to inspect structural elements and check if they have been affected by fire.
Specialist advice may be required from local authority building control teams, structural engineers or urban search and rescue tactical advisers.