Installing an Outside Tap

Installing an outside tap might sound a bit too much like proper plumbing. But as long as you have access to a cold water pipe inside the house, at the right place to bring a tap through to the outside, it’s really a simple step-by-step operation.

There are three main parts to the job:

  • Drilling through the wall
  • Fixing the tap to the wall
  • Connecting to the water supply

In fact many DIY stores now sell outside tap kits which have everything you need apart from the drill bit. But before you run out and buy one you need to see if your pipes are in the right place for a simple job.

Look for a site outside where there is a clear space to mount the tap, with a drain nearby. Measure the distances to the spot, both height and length, from one or two major features like a window or door frame. Then go inside and measure from those features so that you can mark the same spot inside. With many houses having kitchens towards the rear it’s often possible to connect to the cold water supply under the sink.

What if My Pipes aren’t Accessible?

If there aren’t any convenient pipes it’s not the end of the world but it could be the end of the job as a DIY project. You will have to extend the cold water supply to bring a pipe near enough to reach the place where you want the outside tap supply to go through the wall of the house.

While not impossible, it is probably a job for a plumber and it could involve considerable building work, depending on the route the pipe has to take.

Assuming you do have accessible pipes you can go ahead. Most kits provide a connector of the self-cutting type and the current regulations state that the tap should have an isolating valve and a double-check valve to prevent water flowing backwards. Most kits will include these items.

Drilling the Hole

The hole should really be drilled through from both ends as this minimises the surface damage when the drill breaks through at the other end. But this means incredibly fine measurement and accurate drilling in all three planes, so that the holes meet properly in the middle. This may be too much for many DIY beginners.

The solution to this is to drill a pilot hole first. But before you start it is utterly crucial to use a pipe and cable detector to check that you aren’t going to damage anything when you drill through. These can be bought from DIY stores or hired for the day.

Two-Part Drilling Operation

Use one long drill with a smaller diameter than you need and drill the hole from the outside to the inside. This means the damage caused when the bit comes through is on the inside, where you can repair and repaint easily. If you are lucky, the damage will be small enough to then be hidden by the larger hole.

Take your second drill bit, which should be big enough for the pipe to pass through. Drill two-thirds of the way from the outside using the first hole as a guide. Then switch to the inside to drill the final two thirds.

Attaching the Tap

Push the pipe through the hole and fit it to the outside tap first. How you fit it will depend on the type of tap and type of pipe supplied so follow the instructions on the kit.

Wrap plumbers tape (PTFE) around the screw thread for a watertight join. Then fasten the tap to the wall. Most kits have a separate bracket that’s screwed to the wall, then the tap is mounted on that.

Connecting Inside the House

Now it’s time to fix the connector inside the house to the cold water supply. Some kits have a tap (isolating valve) and self-cutting connector all in one, others will have the connector as once piece and the tap will be inline, in the hose. It doesn’t really matter which type you use as long as you have the space to fit the parts you choose.

In theory the self-cutting connector can be attached without having to cut off the water supply but it’s worth doing that anyway. If something goes wrong you’ll be trying to find the stopcock and turn it off while you and everything around you is being drenched! So turn the supply off and open the cold water tap to drain the excess before you start.

Check and Check Again

Position the self-cutting tap over the cold water pipe and screw the cutting end down, following the manufacturer’s instructions. Then re-check that everything is on properly and tight and connect the pipe to the outside tap to the self-cutting connector, again using PTFE tape around the join.

Then turn the water on and everything should work perfectly. Check all the joints for leaks, re-tightening if necessary. Job done.