Devon and Somerset Fire and Rescue Service recently attended an incident involving a fire in the first floor lounge wall cavity of a three storey detached dwelling of timber frame construction. 

The fire investigation officer Andy Justice identified a number of risk critical issues which could have adversely affected the outcome of firefighting operations and crew safety.  

The fire investigation established that the fire had been burning for several hours prior to being discovered by the occupants who were present within the property throughout this time. Whilst smoke detectors were fitted and were operable, they failed to activate due to the fire and smoke being contained within wall and ceiling voids.  

The occupiers also reported seeing smoke percolating from around ground floor skirting boards and window sills. Subsequent investigations confirmed that there was considerable smoke and heat spread throughout all floors of the dwelling caused by the pressurisation of the cavities which allowed the fire to develop undetected.  

FIRE was told that, post fire, that there had been considerable structural damage with the loss of the floor immediately above the fire origin. This was initially identified by fire crews who had to operate on hands and knees, in close to zero visibility, due to the affects of heat and smoke. On opening the door to the room above the fire, the carpet was felt to be 'spongy' to the touch which resulted in the BA Crew stopping their search. Only through the use of a thermal image camera was it established that the floor structure had been destroyed by fire leaving a drop to the floor below; this drop was obscured by the carpet that remained in situ. 

Group Manager Chris Blackburn commented: "The means by which this fire spread throughout the building cavities and the potential risks for firefighters prompted the service to issue a risk information alert to all operational personnel. The alert highlighted and explained this event, together with the potential for undetected fire spread and the possible loss of structural integrity in buildings utilising modern methods of construction". 

"Firefighter safety is always at the forefront of any operational commander's decision making processes and so sharing the lessons learnt is vital to maintaining a safe workforce. Modern method of construction type buildings are indistinguishable from traditional construction and it is often the case that this is not realised until well into the firefighting phase of an incident, perhaps it is now appropriate for the first crews in attendance, to include in their information gathering exercise, how is this building constructed?" 


Posted: 09.39am, 18.05.11