The LWF Blog

Fire Engineering Design and Risk Assessment – Compartmentation & Sprinklers – Part 9

October 11, 2018 10:52 am

In LWF’s fire engineering blog series for Architects and others in the building design business, we have been looking at compartmentation and how can be used both in prescriptive and fire engineered solutions. In part 8 of this series, the provision of a fire safety strategy for a building was discussed and in part 9, we move onto how compartmentation and sprinklers work together.


The effectiveness of sprinkler systems at controlling fires has had a definite impact upon the way compartmentation is used. It is common to see a design where compartment size is substantially increased when sprinklers are used. In addition, in some cases it has been possible to reduce the level of fire resistance of the compartment where sprinklers are used.


The compartment size can effectively be doubled where sprinklers are included in the design and this has been the case for some considerable time. The Post War Building Studies, which was published in 1944, was the first to suggest the amendment to use and this was further established by the 1965 Building Regulations, where its use was limited to shops.


Approved Document B, most recently published in 2010, allows for similar increases in compartment size where sprinklers are used in other types of buildings.


While there are no indications that the doubling of compartment size when sprinklers are used is in any way unacceptable or dangerous in practice, it can be restrictive to operate under that single correlation when real design and building situations call for different reasons for compartmentation and the potential consequences of a fire where compartmentation fails can be drastically different from that originally envisaged.


While both sprinkler systems and compartmentation are mainstays of active and passive fire protection measures, they should be used as part of the fire safety strategy specifically designed for that build, rather than in a ‘one size fits all’ manner.


Structural fire protection is covered by British Standards and the Institute of Structural Engineers and largely follows the pattern of the recommendations for compartmentation in terms of fire resistance. While the majority of structural fire protection falls outside of the scope of CIBSE Guide E (the basis of guidance for this blog series) it should be noted that substantial research work has been undertaken on structural fire protection for buildings, which has implications for fire-resistance requirements for compartmentation. In addition CIBSE Guide E is currently being re-written and may have more to say on this area in the future.


In part 10 of this series, LWF will touch on severity of fires in enclosed spaces and equivalent fire resistance periods. 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.


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.


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