The LWF Blog
Fire Engineering Design and Risk Assessment – Assessment of Landing Valve Locations – Part 41May 13, 2019 1:39 pm
In LWF’s Fire Engineering blog series for Architects and others in the building design industry, we have been discussing firefighting. In part 40, we began to look at how the most appropriate location for landing valves can be ascertained and noted that where one landing valve is installed per staircase, it should be located within the staircase enclosure and where two are to be installed, one should be in the staircase enclosure and the other should be placed adjacent to the door to the fire compartment. In part 41, we continue from that point.
In BS 9999:2017 Fire safety in the design, management and use of buildings – Code of practice and also NFPA 1 Fire Code the suggestion is that landing valves should be located at each intermediate landing between floor levels, allowing firefighters to connect the hose only half a floor below the fire floor, rather than – potentially given the previous recommendations – one to two floors below. Such a design decision would therefore result in reduced hose line length and would limit the potential for congestion on staircases.
Fire safety: Approved Document B – The building regulation in England covering fire safety matters within and around buildings agrees with NFPA 1 on another point and that is that landing valves should be located so that every part of every storey of the building is within a set distance from a fire main. While the principle is sound, it does not take into account the standard operating procedures of the Fire Service, the fire-resistant construction surrounding and protecting the staircase or the length of the jet from the hose nozzle.
When planning hose reel coverage, recommendations say that every part of every area should be within 6 m of a hose reel nozzle, however, because this does not take into account the throw of a water jet from a nozzle fed by a rising main, this can be increased to 10 m as a reasonable measurement for planning purposes.
In order to get a more accurate idea of hose reel coverage, the travel distance should be measured from the fire-resisting door of the staircase in which the landing valve is installed and should include an element for the throw of the jet of water. CIBSE’s Guide E recommends that every part of each storey is within 50 m of the fire-resisting doors giving access to a compartment from a staircase containing landing valves. (50 m equals two lengths of laid hose plus a jet throw of 10 m).
In part 42 of this series, LWF looks at external access for the Fire Service. 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 0800 410 1130.
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