The LWF Blog
Fire Safety Engineering for Design – Sprinkler Protection – Part 217
January 13, 2025 11:35 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 216, LWF began to review the benefits of sprinklers. In part 217, we continue to look at the potential concessions possible when sprinklers are included in the fire safety design of a building.
It is possible that the inclusion of a sprinkler system in a building may positively affect the fire-resistance levels of the construction elements. A sprinkler system works to subdue fire growth and so the fire severity and duration are likely to be reduced. Therefore, load-bearing structural elements will maintain their load-bearing capacity for longer and any separating elements are more likely to maintain their integrity and avoid transferring heat. For these reasons, it could be possible to reduce fire-resistance levels in cases where sprinkler systems are installed.
The use of mechanical smoke ventilation is made possible by the impact of a sprinkler system on the smoke from a fire. The sprinkler works to cool and subdue the fire leading to a smoke output that is cooler – and less than if the fire growth were not suppressed. The smoke production rate is simpler to determine, therefore increased confidence in the extract rate required can be achieved. The resulting smoke may be effectively removed by mechanical fans, which may be negatively affected by extremely hot smoke in a non-sprinklered environment. While natural ventilation may still be used where it is possible, the mechanical fan option may be required in conditions where access to outside air is not possible, e.g. basement levels.
The number of firefighting shafts may be reduced in buildings where sprinkler systems are operating, because the sprinklers are overwhelming the fire.
The separation distance between buildings may be reduced in situations where both buildings are sprinklered. This is because the heat flux from a fire will be controlled by the sprinklers and fire is much less likely to pass between the adjacent buildings. The Building Regulations 2010 allow for the distance between sprinklered buildings to be reduced by one-half.
Sprinklers may be used in buildings with atriums, healthcare buildings, shopping malls and other assembly buildings to great effect, and other concessions may be possible within that design.
In part 218 of LWF’s series on fire engineering we will talk about fire engineering using sprinkler systems. 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.