- Identify potential breaches to cavities or adjoining cavities
- Assist with checking for hot spots that may reignite
A thorough check of concealed spaces, internally and externally, should be carried out before exposing the fire. The most appropriate method should be used for accessing concealed spaces, and there should be appropriate and sufficient firefighting media available. It may be necessary to cut away elements of the structure to locate the fire or enable adequate extinguishing media to be applied, for more information see Cutting away.
Inspection covers, or doors may provide access to concealed spaces. Lifting floorboards or ceiling tiles and opening access hatches may allow access to areas under floors or above ceiling areas.
Accessing concealed spaces should take into account the potential impacts on ventilation, structural integrity and utility supplies.
Ventilation
Creating an opening to a concealed space, compartment or building may impact on ventilation. Natural or mechanical ventilation can have a considerable effect and may intensify the speed of firespread through a concealed space. Sources of ventilation in buildings (including inlets, pathways and outlets) should be identified, evaluated and monitored to establish the potential effects on fire development. For further information about the effects of ventilation, see hazard Uncontrolled ventilation.
Structural integrity
Techniques such as cutting away or removing areas of brickwork to expose wall cavities may be required but can have an impact on structural integrity. This activity may require specialist teams and equipment.
Utility supplies
To avoid the risk of electrocution or damaging pipework, isolate utilities before accessing concealed spaces. The impact of isolating utilities should be considered; for example, isolating utilities may impact on fixed installations. For further information about isolation of utilities, see Utilities and fuel.