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. Outside taps are designed to be easily connectable to hoses and provide a convenient water source for a pressure washer, or for the use of a hose to wash the car or water the garden. Having an outside tap also means there is no need to impede the use of other water outlets in the home – for example, by fitting a garden hose to the kitchen tap.
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.
A typical outside tap features a brass handle with a single spindle, and a male ¾ inch BSP thread for a 15 mm nozzle which allows for the connection of hoses. 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 plumbing
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 connected 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 for running through the wall, ranging 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, as 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.
To prevent the contamination of the mains via the possible back flow of e.g. dirty water in a hose, water regulations require that the supply pipe is fitted with a double check valve. 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. Depending on the kit, this may be in the form of an elbow tap connector, or it may be integrated with a 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 will 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.