Section 15 Fire mains and hydrants

Fire mains and hydrants

  1. Introduction
    1. Provision of fire mains
      1. Number and location of fire mains
        1. Design and construction of fire mains
          1. Provision of private hydrants


            15.1Fire mains are installed in a building and equipped with valves etc so that the fire and rescue service may connect hoses for water to fight fires inside the building.

            Fire mains may be of the ‘dry’ type which are normally empty and are supplied through hose from a fire and rescue service pumping appliance. Alternatively, they may be of the ‘wet’ type where they are kept full of water and supplied from tanks and pumps in the building. There should be a facility to allow a wet system to be replenished from a pumping appliance in an emergency.

            Provision of fire mains

            15.2Buildings with firefighting shafts should be provided with fire mains in those shafts and, where necessary, in protected escape stairs. The criteria for the provision of firefighting shafts and fire mains in such buildings are given in Section 17

            15.3Fire mains may also be provided in other buildings where vehicle access is not provided in accordance with Table 19 (see paragraphs 16.6 & 16.7) or paragraphs 16.2 or 16.3.

            Number and location of fire mains

            15.4In buildings provided with fire mains for the purposes of paragraph 15.3, outlets from fire mains should be located to meet the hose criterion set out in paragraph 17.8. This does not imply that these stairs need to be designed as firefighting shafts.

            Design and construction of fire mains

            15.5The outlets from fire mains should be located within the protected enclosure of a stairway or a protected lobby where one is provided (see Diagram 52).

            15.6Guidance on other aspects of the design and construction of fire mains, not included in the provisions of this Approved Document, should be obtained from BS 9990:2006.

            Notes:Wet fire mains should be provided in buildings with a floor at more than 50m above fire and rescue service vehicle access level. In lower buildings where fire mains are provided, either wet or dry mains are suitable.

            Provision of private hydrants

            15.7Where a building, which has a compartment of 280m2 or more in area, is being erected more than 100m from an existing fire-hydrant additional hydrants should be provided as follows;

            • aBuildings provided with fire mains – hydrants should be provided within 90m of dry fire main inlets.
            • bBuildings not provided with fire mains – hydrants should be provided within 90m of an entry point to the building and not more than 90m apart.

            Each fire hydrant should be clearly indicated by a plate, affixed nearby in a conspicuous position, in accordance with BS 3251:1976.

            15.8Where no piped water supply is available, or there is insufficient pressure and flow in the water main, or an alternative arrangement is proposed, the alternative source of supply should be provided in accordance with the following recommendations:

            • aa charged static water tank of at least 45,000 litre capacity; or
            • a spring, river, canal or pond capable of providing or storing at least 45,000 litres of water at all times of the year, to which access, space and a hard standing are available for a pumping appliance; or
            • any other means of providing a water supply for firefighting operations considered appropriate by the fire and rescue authority.