The LWF Blog
Fire Safety Engineering for Design – Sprinkler Protection – Part 214
December 16, 2024 11:45 amLWF’s Fire Safety Engineering blog series is written for Architects, building designers and others in the construction industry to highlight and promote discussion on all topics around fire engineering. In part 213, LWF talked about sprinkler protection and their history. In part 214, we continue to discuss sprinkler systems.
Large fires occur due to many contributing factors, but two of the most common are a delay to discovering the fire and a resultant delay in attacking the fire. Automatic sprinkler systems are designed to detect and immediately respond to the presence of fire by triggering the sprinklers in the area of fire origin. This means that the fire growth is restricted and resulting damage is confined to that area.
Automatic sprinkler systems are known to have a good performance record and it would not be overstating to say that the majority of fires in sprinkler-protected premises are brought under control by four sprinklers or fewer.
The NFPA’s real fire data shows that in sprinkler-protected premises, 88% of reported fires were controlled by one or two wet-pipe sprinklers, or 73% were controlled by only one or two dry-pipe sprinklers.
A report published by the NFPA in 2005 showed that when sprinklers are present, the chances of occupant death due to fire are reduced by around 50 – 75% and average property loss per fire is cut by 50 – 67%, compared to fires where no sprinkler system is installed. It is likely these figures understate the effectiveness of sprinklers, as they exclude unreported fires but do include all types of sprinkler system regardless of age or operational status.
Sprinkler systems and their components are subject to established independent third-party certification and such schemes are referenced in current fire safety guidance, such as Approved Document B, BS 9999, BS EN 12845 and the Technical Bulletins of the Loss Prevention Council.
Although the reliability of a properly commissioned, installed and maintained sprinkler system is practically without doubt, there are instances where a sprinkler system is unable to control a fire. Data from the NFPA for fires in the US indicate that sprinkler systems failed to operate in only 9% of building fires. However, 64% of the 9% were due to the system being shut off at some point before the fire started. For this reason, sprinklers cannot be considered to be 100% effective.
In part 215 of LWF’s series on fire engineering we will continue to discuss sprinklers, and in particular, why less than 100% effective can still be considered sufficient in terms of fire safety. 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 since 1986 to produce innovative and exciting building projects. If you would like further information on how LWF and fire strategies could assist you, please contact the LWF office on 0800 410 1130.
While care has been taken to ensure that information contained in LWF’s publications is true and correct at the time of publication, changes in circumstances after the time of publication may impact on the accuracy of this information.