IT’S amazing, most people think that in the case of a fire breaking out in a building that has a commercial sprinkler system installed all of the sprinkler heads will go off at the same time. Never has anything been further from the truth. In the vast majority of incidents one or two sprinkler heads control the fire.
When a fire occurs only the sprinklers in the immediate vicinity automatically start to operate and discharge water to control or extinguish the fire. Compared to the amount of water used by the fire brigade the amount of water discharged by a sprinkler is approximately 5% of that discharged by a fire hose. An IT specialist once asked us to remove sprinkler heads from his computer room as he was concerned the water would damage his computers if a sprinkler head went off. We replied saying the before his computers would get a soaking they would have turned to melted plastic!
Automatic sprinkler systems date back to the 19th Century and their development was mostly led by fire insurance companies. The low average loss in the case of sprinkler protected buildings has established a record unbeaten by any other form of protection. There are two main reasons why this is so; sprinklers extinguish a fire while it is still small restricting the direct fire damage to a minimum; and the effect of a loud alarm (mechanically operated from the sprinkler alarm valve) which rings immediately and automatically attracts the attention necessary to limit water damage to a minimum.
Automatic sprinkler systems require no human assistance to control and extinguish fires; they are on duty 24/7; their efficiency is not impaired by the presence of smoke or fumes; and they are not hindered by access to difficult sites like the 24th floor of a tower block. This refers to sprinkler systems installed in commercial buildings, shopping malls, hotels, warehouses, banks, office blocks, tower blocks, etc. There are sprinkler systems installed whereby large amounts of water are immediately discharged but these are mainly for LPG storage tanks and other high risk applications. Regarding the legal aspects of fire control it is interesting (and welcoming) to note that the stipulations in Chapter 11 of the Harare Model building by-laws are fairly stringent and insist on sprinkler protection in all buildings over 29m high and in large buildings with a floor area over 3,701m2, and various other areas such as basements and parking garages.
This is certainly not the case in the UK, for example. We believe that these stipulations should be taken a step further to include mandatory sprinkler protection for hospitals, Old People’s Homes and certain night clubs which have been the subject of horrendous fires overseas in the last few years. The average cost per square meter of a sprinkler system is $20/ m2. Compared this to say tiling which runs at anywhere between $25 to $35 for standard tiling. Compared to the untold price of experiencing a major fire this could be considered a small price to pay.
