The LWF Blog
Fire Safety for Facilities Management Personnel – Sprinkler Installation Design – Part 241
February 26, 2024 12:32 pmLawrence Webster Forrest (LWF) is a specialist fire engineering and fire risk management consultancy whose aim is to give information on best practice in fire safety for facilities management personnel through this blog series. In part 240, LWF talked about sprinkler heads. In part 241, we will talk about the proper location of sprinkler heads.
Where sprinkler protection is installed in a building, it is usual for it to cover the entirety of the floor-space in the building. Partial protection of a building is unusual and generally-speaking, to be avoided. This is due to the fact that a fire could start in an unprotected area of the building and spread to the protected area. The sprinklers in the protected area would not be able to suppress the already established fire, as sprinklers are designed to work on small fires that have just started.
Sprinkler system heads should, however, be omitted from areas in which water discharge could cause a serious hazard. This might be the case in an industrial area containing molten metal, electrical switchgear or transformer rooms, rooms containing oil or flammable liquids, toilets and some stairways.
In all cases where there is a reason sprinklers must be omitted from an area, that area should be separated from the protected area by fire-resistant construction with a duration of 120 minutes.
Where a sprinkler-protected building abuts another unsprinklered building, it is important to ensure that fire cannot spread from the unprotected building to the protected one. Separating walls with a fire resistance of 120-240 minutes is recommended by BS EN 12845, with the variation depending upon circumstances.
Sprinkler Performance
Most studies on the effectiveness of sprinkler installations at controlling or extinguishing fires put the overall efficacy between 91 and 98%. The majority of the remaining percentage of sprinkler failure is due to human error in installation, maintenance or inappropriate usage of the sprinkler system.
Sprinkler system reliability is also very high. Leakages are rare and tend to be due to mechanical damage, where it has been damaged by outside force, the pipework has frozen or there is excessive temperature and corrosion (such as in some industrial environments). In an office environment, for instance, the probability of sprinkler leakage is very low.
In part 242 of this series, LWF will discuss the recommendations for daily and weekly inspection and test routines for sprinkler systems. In the meantime, if you have any queries about your own facilities or wish to discuss this blog series, please contact LWF on freephone 0800 410 1130.
Lawrence Webster Forrest is a fire engineering consultancy based in Surrey with over 35 years’ experience, which provides a wide range of consultancy services to professionals involved in the design, development and construction and operation of buildings.
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.