Understanding the impact of fire or firefighting on the various types of structural materials should assist when dealing with fires in buildings.
Firefighting techniques should be based on the type of structural material. For example, cooling may be carried out by using sprays to reduce the temperature of the structure. However, the use of this technique should be exercised with caution, as rapid cooling could weaken the structure. Incident commanders should consider the tactical actions shown in the tables below.
| Structural material |
Tactical actions |
| Blockwork |
- Consider the potential for collapse
- Investigate adjoining compartments for the spread of products of combustion
|
| Cast iron |
- Consider the potential for collapse
- Consider the weight of falling cast iron elements
- Avoid rapid cooling of cast iron due to thermal shock
- Monitor adjacent compartments or structures for conducted heat transfer
|
| Cellular steel |
- Consider the potential for collapse, but do not attempt to predict the mode of failure as this requires an in-depth knowledge of structural engineering
- Consider the effects of the fire’s duration and intensity on cellular steel that has been exposed to heat
- Monitor adjacent compartments or structures for conducted heat transfer
- Consider cooling affected cellular steel to prevent collapse
|
| Cold rolled steel |
- Be aware that failure of cold rolled steel may occur quickly and suddenly
|
| Concrete |
- Consider the prompt use of ventilation due to the thermal capacity of concrete
- Monitor for signs of spalling; this may be an early indicator of collapse
|
| Engineered timber |
- Consider the effects of the fire’s duration and intensity on the engineered timber
- Seek advice on fire engineered strategies
|
| Historic timber |
- Consider the condition of the timber in historic buildings
- Consider the effects of historic building materials used as insulation between floors
|
| Hot rolled steel |
- Due to the potential for early collapse, consider the use of defensive firefighting techniques
- Identify whether steel has been protected from the effects of fire by cladding, and if so assess the condition of the cladding
- Assess what temperature the steel has been subjected to and for how long
- Monitor adjacent compartments or structures for conducted heat transfer
|
| Stone |
- Monitor for signs of spalling; this may be an early indicator of collapse
- Prevent direct application of firefighting jets onto heated areas of structural stone
- Consider applying the tactical actions for concrete in case the material is cast stone rather than natural stone
|
| Structural glass |
- Be aware that large sections of structural glass may fall (or plane) a considerable distance from the building
- Identify alternative access and egress routes to avoid areas of glazing affected by fire
- Avoid rapid cooling of structural glass due to thermal shock
- Consider working at height procedures if personnel are working inside the building near to where glazing has failed
|
| Structural insulated panels (SIPs) |
- Due to rapid and intense heat and smoke and the potential for collapse, consider the use of defensive firefighting techniques
- Monitor for rapid firespread that could lead to flashover in the early stages of a fire
|
| Structural timber composites (STCs) |
- Monitor STCs involved in fire for unexpected behaviour or signs of collapse
- Assess what temperature the STCs have been subjected to and for how long
|
| Traditional or lightweight timber |
- Consider the potential for rapid undetected firespread
- Investigate any potential firespread; cutting away of cladding or coverings may be required
|
