Installing an Outside Tap

A supply of water outside the house is a great help to the serious gardener. By choosing a threaded tap you will be able to connect hosepipes, sprinklers and automatic watering systems as well as being able to clean off those muddy boots before stepping inside!

  • Outside tap
  • Pipe cutter or hacksaw
  • T-connector and elbow connecters
  • 15mm (0.6in) copper pipe
  • 22mm (0.9in) copper pipe
  • Stop valve
  • Drain valve
  • Heavy duty drill and bit
  • Screws
  • PTFE tape
  • Expanding foam filler

Positioning the tap

The tap needs to be above the interior floor level, close to the rising main, and above the main stopcock. Ideally, it should be positioned over a drain grid or hardstanding and at a convenient height for filling cans and attaching hosepipes.
Situate the tap and mark the position of the wall plate holes on the wall. Then mark the position above it for the hole through the wall.
Tip: Check there are no electrical cables inside the wall at the drill points, and that there are no other obstructions between the hole and the rising main.

Preparing the internal pipes

Close the stopcock and turn on the nearby taps to drain all water from the pipes.
The rising main will normally be 15mm or 22mm (0.6 or 0.9in) of copper piping. Any other types require specialist advice.
Remove a section of pipe and fit a T-connecter (either a compression or soldered type).
Add a small section of 15mm (0.6in) copper pipe, then fit a stop valve so you can isolate the tap in winter.
Install a further small length of pipe then fit a check valve to prevent siphoning back from the outside into the mains system (unless one is already built into the tap).
Fit a drain valve to ensure all the outside parts are completely drained of water when the system is turned off over winter.

Fixing through the wall

Drill a small pilot hole – you will need a heavy-duty drill and a drill bit long enough to reach through the wall.
Make it easier by drilling a small pilot hole on either side of the wall to mark the positions. Then – with a drill bit large enough to make a hole for a 22mm (0.9in) copper pipe – drill again about half-way through the wall from either side.
Insert a sleeve of 22mm (0.9in) copper pipe to isolate the supply pipe from the internal cavity spaces.
Cut a length of 15mm (0.6in) pipe to go through the wall with room at each end for further compression or soldered elbow joints.

Connecting the inside and outside

Fit an internal elbow joint, then blow out the debris from inside the pipe and feed through the wall. Join up the internal elbow with a further small length of 15mm (0.6in) pipe, connecting it to the drain valve.
Trim the outside end of the pipe to leave just enough overlap for an elbow connecter and turn it towards the tap position.

Assembling the tap

Securely fit the tap to the wall with screws through the wall plate.
Join the tap to the elbow joint with a further piece of 15mm (0.6in) piping.
Attach the tap to the wall plate using PTFE tape to ensure the fitting is leak free.
If the tap is not vertical, dismantle and wind further tape around the fitting to shorten the thread.
Turn on the mains stopcock and the isolating stop valve – checking for leaks each time.
Finally, seal any gaps through the wall with expanding foam filler.

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