The LWF Blog

Fires in Car Parks – An Overview of Cause and Effect – Pt One

June 26, 2014 1:19 pm

When considering the development and control of fires in car parks and the impact upon a fire safe design, we should begin by discussing the potential causes of fire ignition.

Although there are no statistics directly relevant to car parks, we can draw certain conclusions from the trends seen in other areas. In the year 2012/13, the Fire and Rescue Services attended 20,300 road vehicle fires, which overall is a 75% decrease on the same period a decade ago. This figure may reflect the increased safety of car manufacture in that period. 

However, of the 154,000 fires which the Fire and Rescue Services visited, 45% of these were deemed to have been deliberate fires. National statistics from the same year show that vast majority of these deliberately set fires were not in domestic properties, but in ‘other properties’ and vehicles.

So, those architects and engineers considering fire control and protection within car parks (while considering those cars that may catch fire due to, for example, an electrical fault), must also take into account the impact of those who might wish to set a fire deliberately.

Car parks are particularly vulnerable to such attacks, as the nature of them requires access, either by multiple members of staff in a private car park, or by the public, in a public car park.

Fire load within cars

Although technologically speaking, the risk of fire simply occurring in a car has decreased, the impact of such a fire has increased. As fuel tanks have become larger, the capacity for a greater explosion which can cause damage to areas outside of the car itself, has increased. Of course, in a car park situation, the cars are parked side by side and so fire spread between vehicles is potentially more likely. 

The extra cabling involved in modern cars has increased in recent years, due to electrical gadgets such as electric wing mirrors, and the extra cabling involved itself increases the potential fire load.

Types of Car Park

The type of car park can have a significant impact upon the way a fire develops and what type of danger it poses. An enclosed, often underground, car park can provide little air for the fire to burn. The incomplete combustion can therefore lead to the release of more toxic gases into the area, which is a significant danger to any persons within the car park.

An above ground and open-sided car park provides all the ventilation that a fire could need to burn and so the blaze will continue to grow as long as combustible materials are available. 

In both cases, it is common for ceiling heights to be low in multi-storey car parks to maximise the amount of available parking levels. The low ceiling height allows hot smoke and heat to build up just above the cars. This will also help the fire to spread by means of convection and radiation.

Next week’s blog will look at the impact of the Building Regulations upon car park design and build, compartmentation and fire precautions. In the meantime, if you have any queries about your project, or wish to speak to a fire engineer, please contact Peter Gyere on 0208 668 8663.

LWF is a fire engineering and fire risk management consultancy with over twenty five years’ experience in the development of fire engineered technology and the application of fire safety standards including fire engineered techniques.

Statistics: Fire Statistics Monitor 2012/13 England