The LWF Blog

Fire Engineering Design and Risk Assessment – Firefighting & Rising Water Mains – Part 37

April 23, 2019 2:01 pm

In LWF’s fire engineering blog series for architects and others in the building design business, we have been talking about firefighting and rising water mains in buildings. In part 36, we looked at wet rising water mains and horizontal mains/internal hydrants. In part 37 we will discuss the parameters to be considered when deciding where internal mains and landing valves should be located in a building with a rising main.


Planning the location of internal mains and landing valves

Approved Document B states that outlets from a fire main should be located in the fire-fighting lobby, or in the case of blocks of flats, in the firefighting stairway. It is most common to have only one landing valve on each level of the building/riser, but it may be decided that two are necessary depending upon circumstances.


Where deep basements are involved, it may be appropriate to place landing valves in these locations too. Each valve should be installed so the lowest point is around 750 mm above floor level (i.e. around 2.5 feet off the ground).


In a building with automatic sprinklers, every part of every floor of the building should be within 60 metres of the fire main outlet. In buildings without sprinkler systems, each part of every floor should be within 60 metres of the fire main outlet too, or within 45 metres of the outlet from a fire main in a protected stairway.


As only the landing valves which are required to be fire safe are provided, it is important that they are protected from vandalism by enclosure in locking boxes or securing the valves in a closed position with straps and padlocks.


NFPA 1 is a US produced standard used in various parts of the world. It includes recommendations that landing valves are placed as follows:


 At each intermediate landing between floor levels in every required exit stairway


 On each side of the wall adjacent to the exit openings of horizontal exits


 In buildings other than covered malls, in each exit passageway at the entrance from the building areas into the passageway


 In covered mall buildings, at the entrance to each exit passageway or exit corridor, and at the interior side of public entrances from the exterior to the mall


 At the highest landing of stairways with stairway access to a roof and on the roof where stairways do not access the roof.


It should be noted that NFPA 1 guidance should only be used outside of the US in countries where the guidance has lesser requirements, not greater ones.


In part 38, LWF will continue to look at those standards providing recommendations on placement of internal mains and landing valves. 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.


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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