Outside tap

An outside tap or garden tap is a tap fitted to the outside of a building which delivers water for use outside of the property. They provide a convenient water source for a hose or a pressure washer. Having an outside tap also means there is no need to block e.g. the kitchen tap with a garden hose.

Outside tap overview

Outside taps are usually made out of brass. This helps to prevent them from corroding from their exposure to the elements all year round.

The handle of an outside tap is typically brass with a single spindle. The hose connector is usually a male ¾ inch BSP thread with a 15 mm nozzle. The nozzle usually features a simple layering to allow for the secure connection of a hose via a jubilee clip. However, this nozzle can be replaced with nozzles which are designed to fit directly into Hoselock-type hose connectors.

Outside tap supply

As for the supply side, a typical outside tap usually has a male ¾ inch BSP thread at the rear. This usually connects to a 90 degree tap connector which may also feature the backing plate for securing the tap to the wall. The tap is then connected to the supply pipe via a solder or compression fitting.

Alternatively, the backing plate and tap connector may have their own integrated length of copper pipe. This usually ranges in length from 350 – 400 mm. This is commonly found on outdoor tap kits and can be trimmed to the desired length with some pipe cutters.

Outside taps should always be supplied by the mains and never from a cold water storage cistern. This is because a storage cistern would not offer satisfactory pressure.


There are several possible ways to connect an outside tap to the mains, such as teeing off from a property’s underground service pipe. However, the most common configuration is that the tap is fitted on the external wall of a kitchen or downstairs toilet, and the supply for it is tee’d off from the nearby pipework inside that room.

Water regulations require that the supply pipe is fitted with a double check valve. This is in order to prevent the contamination of the mains via the possible back flow of e.g. dirty water in a hose. However, many outdoor taps available on the market at the moment come with their own integrated double check valve.

An outdoor tap must also be fitted with an isolation valve. This will allow for servicing or repairs to carried out without having to turn off the entire water supply to a property. In periods of freezing weather, an outdoor tap should always be isolated and the tap itself left open. This will prevent any water in the pipework from freezing and then bursting the pipe when it thaws.

Outdoor tap kits and fittings

While individual taps are available from most DIY stores and plumbing merchants, it is also possible to buy outdoor tap kits. These come with everything necessary for installing an outdoor tap in accordance with water byelaws.

An outdoor tap kit typically consists of:

  • The tap itself
  • The wall mounting. This may be in the form of an elbow tap connector, or with an integrated length of pipe that runs through the wall.
  • A braided hose connector. This is used to connect the tap to the tee point on the mains inside the property.
  • An isolation valve/service valve
  • A double check valve. This is necessary if the outdoor tap does not have its own integrated check valve.
  • Screws and wall plugs

Some outdoor tap kits may also come with a spool of PTFE tap. This helps to ensure a watertight fitting on compression joints.

It is also possible to buy small thermal insulation jackets or “cosies”. These can be slipped over an outside tap and tied in place to prevent the tap from freezing in the winter.