The LWF Blog

Fire Engineering Design and Risk Assessment – Fire Suppression & Sprinklers – Part 4

July 20, 2017 8:32 am

In this Fire Engineering Design and Risk Assessment blog series for Architects and others in the building design arena, we’ve been looking at Fire Suppression & Sprinkler Systems. In Part 3 of this series, we looked at the development of sprinklers in the years since their inception and the basic components that make up a sprinkler system. In Part 4, we’re going to discuss what makes sprinklers a valuable tool in your fire protection arsenal.


There are two factors which commonly combine to produce large fires. The first is that the fire is not discovered at an early stage, giving it time to develop and grow. The second is that once it is discovered, there is a delay before firefighting can begin.


Sprinkler systems are designed to overcome both these hurdles at once. The fire is detected by the system and then the sprinkler becomes operational, which limits growth of the fire in the area it began, and in some cases, suppresses the fire completely.


As the fire is much less able to grow to a large size when automatic sprinkler systems are installed and in good working order, it is likely that the fire will be contained in a small area and will only cause a small number of heads to operate. The concerns of extensive water damage in premises from sprinklers becoming active is needless, as only those heads which are triggered by the fire itself will become operational.


In a study undertaken by the National Fire Prevention Association in 1999, real fire data was collected and analysed, showing that more than 60% of fires reported were controlled by a single sprinkler head. In addition, more than 95% of fires were controlled by ten or fewer sprinkler heads.


Reported fires, however, do not include those fires which occurred but were not reported to the Fire Service, and so there will be many small unaccounted for fires which were subdued and extinguished by a small amount of sprinkler heads, backing up the trend shown in the statistics.


The NFPA also reported in 2005 that where sprinkler systems are installed and operational, the chances of dying in a fire were reduced by half, as is the likelihood of property loss. While these figures are based upon any age and working order of a sprinkler system, as increased reliability and concentration on proper operation become paramount, it is likely that the real results will be much greater in the future.


Further information on the merits of sprinkler systems in buildings can be found in Approved Document B, BS 5306, BS 9999, BS EN 12845 and the LPC’s Technical Bulletin in the UK.


In Part 5 of this series, we will be looking at those times when a sprinkler system does not control a fire and the reasons behind those failures. In the meantime, if you have any questions about this blog, or wish to discuss your own project with one of our fire engineers, please contact us.


Lawrence Webster Forrest has been working with their clients for over 25 years to produce innovative and exciting building projects. If you would like further information on how LWF and fire strategies could assist you, please contact Peter Gyere on 020 8668 8663.



Share this post