How To Fit An Outside Tap: A Complete Guide

Written by  John Davies
Last updated: January 17, 2024

Installing an outside tap is one of the best ways to make watering your garden, washing the car, filling a pool, or washing a mucky pup. The possibilities open up significantly once you have working outside tap. Here’s everything you need to know about fitting an outside tap.

Materials and Tools Needed to Fit an Outside Tap


  •  An outside tap fitting kit: This will make your job easier as such kits usually come with most of the things you need. The average outside tap fitting kit will include the tap’s main body, backplate, valve, screws and some PTFE Seal tape. It may even include pipes and hoses.
  • 15mm and 22mm copper Pipes: We will use copper pipes in this guide, but uPVC pipes can also do the job. You need 2m long, 15mm and 22mm copper pipes. You probably won’t use that much, but that’s okay. These pipes will act as the sleeve of your outside tap.
  • A T-piece: It will serve as a bend and connector. Bends divert water flow, while connectors help join pipes together. You may need more than one T-piece depending on the distance between the water source and outside tap, and the pathway of the pipework that will connect them.
  • Compression joints: They will also serve as bends and connectors.
  • Wall plugs and clips: for holding pipes to the wall.
  • Isolation valve: This will allow you to cut off the outside tap’s water supply anytime. It’s crucial to use a double-check valve instead of the normal ones usually included in the average outside tap fitting kit. A double-check valve ensures that water only flows in one direction, outward, toward the tap itself.
  • PTFE Seal tape: You’ll need them to join pipes together. The PTFE seal tape in the average outside tap fitting kit might not be enough. It might not even be in the kit.
  • Wall sealant or plaster: for filling the hole you will make in the wall during outside tap fitting


  • A hacksaw
  • An SDS power drill and masonry drill bit (22mm and 24mm)
  • Spanner

How to Fit an Outside Tap: Step-By-Step Guide

Now that you have everything you need, here is an easy-to-follow step-by-step guide to outside tap fitting.

Step 1: Choose a Water Source for Your Outside Tape

The water source should be as close as possible to the mains pipe. However, you don’t want it to be too close that it starts to affect water pressure in other parts of the house. Therefore, when fitting an outside tap, the right water source is often the domestic cold water pipe connected under the kitchen sink. Whatever location you choose, ensure there is enough room to fit the T-piece.

Step 2: Cut Into the Feed

Before you start cutting, shut off the feed first. You might have to turn off water at the mains pipe but that’s your only option for now. The alternative is to have water splashing everywhere. So, turn off the water. Then, use the hacksaw to cut the chosen source pipe. You can mark the spot before cutting if it will make things easier.  

Step 3: Connect the T-Piece and Isolation Valve

When fitting an outdoor tap, most people fit the T-piece facing outdoors. This is okay if you don’t intend to add an isolation valve. So, don’t do that. Let the T-piece face sideways. Doing this lets you fit the isolation valve to the face outdoors. 

Once the isolation valve is installed, use it to cut off water to this pipework. Therefore, you can now turn on the mains pipe. As a result, the rest of this project no longer has to affect water flow to other parts of the house. 

Step 4: Connect the Pipes

Drill a 22mm hole into the wall. Pass the 22mm pipe through this hole and connect it to the insulation pipe. Run the pipework and sleeve to the location you have chosen to fit the outdoor tap.

Step 5: Fit the Outdoor Tap

Taps are usually made up of two parts: a backplate and a main body. Screw the backplate to the outside wall. Then, use the compression joint to connect it to the tap’s main body. You will need to use PTFE sealant tape to seal the joint. Fifteen wraps should be enough. Once the tap’s backplate and main body are in place, tighten them with a spanner or your hands.

Step 6: Test the Outdoors Tap

You have finished fitting the outdoor tap. Now, it’s time to test it. Turn off the isolation valve so water can flow into the outdoor tap. Turn on the tap to see if it’s working. You should also check for leaks.   

Step 7: Finish

Seal leaks and clip the pipes to the wall. Then, seal or plaster the holes you made in the wall. There you have it. That’s all you need to know about fitting an outside tap.

How to Replace an Outside Tap

Follow these steps to remove and replace the main body of an outside tap.


  •  A new outside tap body:
  • PTFE seal tape: to seal the joints


  • A spanner

Step 1: Turn off the Water Supply to the Outside Tap

You can use the isolation valve to do this. If your outside tap doesn’t have this, you will probably have to turn off the mains pipe. It’s because of this kind of situation we recommend adding an isolation valve when fitting an outside tap. Find a way to turn off the water. Then, drain the tap before moving to step 2.

Step 2: Remove the Outside Tap

Unscrew the body from the backplate. The tap’s main body is the only thing you need to remove. Let everything else be.

Step 3: Clean Up the Joint

Remove the PTFE tapes and dirt buildup you find there. They are useless and will only affect the new seal.

Step 4: Screw on the New Outside Tap

Add PTFE sealant tape to the joint. Use 15 wraps. Then screw on the new outdoor tap. You can use a spanner to tighten it.   

Step 5: Test the Outdoors Tap and Make Corrections

Turn the water back on. Then, turn on the tap to see if it’s working and check for leaks. Fix any leak.

Fitting an Outside Tap FAQs

How Much Does It Cost to Fit an Outside Tap?

If you hire a professional plumber, it costs £80 to £200 to fix an outside tap. However, if DIYing it, £35 to £50 should be enough. Your total expenses will be £10 to £20 on an outside tap installation kit and £25 to £30 on other supplies.

Can You Fit an Outside Tap Anywhere?

Yes, you can fit an outside tap anywhere but it’s better to fit it close to the mains pipe. Just ensure the tap is not so close that it affects water flow to other parts of the house. Even better, do what we recommend: fit the outside tap to a water pipe connected under the kitchen sink.

There are usually a minimum of three pipes in this area. You will find hot water, cold water, and waste pipes. Make sure you choose the cold water supply pipe. It’s to be used for fitting an outside tap.   

Why Do You Need a Double Check Valve to Fit an Outside Tap?

You need a double-check valve because the UK building regulations require it. Double-check valves stop the reverse flow of water. If there weren’t a double-check valve in place, if something happened to the water supply, it would cause a vacuum that would build pressure. That pressure could then reverse the water flow and cause the water to be sucked back into the system. A double-check valve also helps prevent contamination of the household’s water supply.

How Easy Is It To Fit An Outside Tap?

Depending on how easily accessible the water source is, the installation can take one or two hours. If there’s an accessible water supply close to the outside wall, it’s a very straightforward job. The ideal scenario is if there’s a kitchen with a sink installed on an external wall. When you have a similar set-up, it’s a straight forwards task of connecting a pipe to the mainline, and you’ll have a functioning outside tap.

However, the task may become significantly more complicated if the water supply isn’t in an accessible position. The job then requires a significant amount of drilling and positioning to ensure that the pipe connects successfully. You’ll need to be careful of all the other piping in the household as well. With an accessible water source, it’s a job that you do at home yourself.

Tip: If you do not have good access to a water supply, I would recommend a plumber they’re used to doing it without causing too much damage.

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