How to Fit an Outside Tap: Complete Step-by-Step Guide

Last updated on October 5th, 2023

Learning how to install an outside tap from scratch can be very difficult, especially if you haven’t done any plumbing before.

Outside tap fitting can be very straightforward once you have done it a few times and you have the right tools and materials, but learning how to fit an outside tap the correct way is key.

I have been plumbing and fitting outside taps for over a decade. I have overcome many problems along the way.

Here I’ll show you how to fit an outside tap based on my on-the-job experiences over the years.

Outside Tap Fitting Materials and Tools

Materials

There are some decent outside tap kits you can buy, but you should try to avoid using a flexible hose when fitting an outside tap.

The brass bib taps are the best outside taps and come with check valves built-in on some.

Flexible and plastic hoses are more likely to leak, especially if there’s a tight bend in them, and might even burst open and flood your house one day.

Also, most kits don’t use an outside tap with a double-check valve which you should use.

There are no outside tap kits that use everything I like to use, but if you can make it work then go for it.

My Outside Tap Kit List

(Click the links to view them on Amazon)

• An outside tap with double check valve
• A hose union backplate with a copper pipe attached: Make sure it is the correct length for going through your wall
• A hose connector: Brass or plastic
• Brass or Speedfit pipe fittings:
  • I typically use a 15mm tee piece and a 15mm 90° elbow, but it depends on your setup
• 15mm isolation valve: Always best to fit one of these but sometimes you can’t
• 15mm pipe: Copper or plastic
• PTFE Tape 
• 6mm wall plugs x 3
• Brass screws x 3: I use 5 x 50mm
• Brown or clear builders silicone

Tools

(with links to Amazon of some of my best plumbing tools)

• An SDS drill (or a corded SDS drill if you don’t have Makita batteries)
• A 10mm SDS drill bit and an 18mm SDS drill bit: 400mm will be long enough to go through most walls. But you may need a 600mm if you have a thicker than normal wall
• A 6mm SDS drill bit: Anything over 50mm long will do
• A screwdriver
• A 15mm pipe cutter
• An adjustable spanner
• Water pump pliers
• A silicone gun
• A marker pen

How to Fit an Outside Tap

Step 1: Drill a Hole

Work out where you want to fit your outside tap, as close to a water pipe as possible.

The height doesn’t really matter, whatever works for you but I like to be able to at least fit a bucket underneath. I would say the ideal height is between 500mm – 800mm.

The most common place is behind the kitchen sink, you can normally connect to the kitchen tap pipe.

Just be sure to leave it in a way to make it easy to fit a new kitchen tap in the future without any problems.

You then need to drill a 10mm pilot hole from outside to in. You will most likely blow the front of the brick out if you drill from inside to outside.

You must carefully measure where to drill before drilling when fitting an outside tap.

Sometimes I will have to drill from the inside, but it takes a lot of practice to not blow the brick out.

I turn off the hammer function on the SDS drill when I only have an inch or so to go and use it in drill-only mode.

Once you have drilled the 10mm hole and checked it’s in the correct place, you need to drill through the 10mm hole with the 18mm SDS drill bit.

Step 2: Fix Backplate and Tap to the Wall

Screw the tap into the hose union backplate without any PTFE tape on then push the pipe through the wall.

Make sure the copper pipe inside the home is in a good position.

When the brass backplate is sitting against the wall, sit the tap straight and mark the 3 screw holes on the outside wall with a marker.

1. Remove the backplate and pipe
2. Drill the 3 x 6mm screw holes carefully
3. Fit the wall plugs in the drilled holes
4. Remove the tap from the backplate
5. Feed the backplate pipe through the wall until there is a two-inch gap between the brass backplate and the wall

Next, you need to:

1. Put some silicone on to give it a good seal
2. Push the backplate flat to the wall
3. Screw in the 3 brass screws
4. Clean off all the excess silicone with some toilet roll

The next job is to wrap some PTFE tape around the threads of the outside tap, around 10 – 15 wraps or more.

1. Screw the outside tap into the backplate
2. Tighten up the tap with your hands, use an adjustable spanner if needed to get it straight
3. Remove any excess PTFE tape on show with a Stanley knife
4. Remove the old hose connector on the end of the new tap

Then you can fit the new hose connector.

These connectors are for quick-connect hose fittings that most people have on their hoses now.

You can use brass or plastic hose connectors but brass ones are better.

The outside tap has now been installed. Everything else is done from inside the house.

Step 3: Connect to the Water Supply

The first thing to do inside is cut the copper pipe from the new outside tap down to the correct length.

The most common way of connecting this to the water supply is to add an elbow to the copper pipe coming from the outside tap using a 15mm brass compression elbow or Speedfit.

Then add a length of copper pipe to the elbow that you are using which should be connected to a tee (you should also fit an isolation valve if you can fit one on).

The tee needs to be connected to the cold water supply, typically under the kitchen sink on most outside tap installations.

You might need other fittings if the cold water supply is not close by, or even the hot water supply if you want to fit an outside hot water tap.

How to Replace an Outside Tap

To replace an old outside tap that is already fitted you only need to replace the bib tap itself and leave the backplate.

Here’s how to replace an outside tap:

1. Isolate the water supply to the outside tap
2. Open the outside tap to let the water out
3. Unscrew the old tap from the backplate on the wall by turning it anti-clockwise
4. Clean up any old tape or dirt from the threads on the old brass backplate on the wall
5. Wrap 15 (or more if needed to get it straight) wraps of PTFE on the threads on the new tap
6. Screw the new tap into the old wall plate and tighten it up with your hands or a spanner
7. Turn the water back on
8. Test the tap is working and check for leaks

How to Attach Hose to Outside Tap

To attach a hose to an outside tap, you will need to fit a hose connector to the tap like the ones in the photos on this page.

You can use brass or plastic hose connectors and they will screw on with your hand.

Your hose should be fitted with a push-fit hose connector which you can push onto the outside tap connector to attach a hose to a tap.

The most common outside taps will come with an old-type brass tap connector. I normally throw these away when I’m fitting an outside tap because they are not made for quick-connect hose connections.

If you want to use the supplied old-type hose connector, you will need to force your hose pipe onto the connector and fit a hose (jubilee) clip on and tighten it with a screwdriver.

How to Fix a Dripping Outside Tap

An outside tap leaking can be fixed in a few different ways:

• Tighten the leaking nut
• Add some PTFE tape to the threads
• Replace the washer
• Replace the outside tap

You can replace the washer on the outside tap, but sometimes it’s so much easier and less of a headache to just replace the tap.

If the leak is coming from the packing gland nut below the handle then this can be tightened up with an adjustable spanner to fix a dripping tap.

If you want to replace the washer, here’s how:

1. Isolate the water supply to the outside tap and open the tap
2. Unscrew the largest nut on the outside tap anti-clockwise with an adjustable spanner
3. Replace the tap washer
4. Refit the tap
5. Turn the water back on
6. Test for leaks

Other Posts You Might Like

• A simple tap cartridge replacement guide to fix that leaky tap
• Learn how to fit a strap boss. A boss is used to connect a waste pipe or condensate pipe to a soil pipe
• Check out my best garden hose and spray gun suggestions for your garden tap
• Here’s my choice for the best outside tap cover to help protect your outdoor tap in a cold winter

Summary

Fitting an outside tap from scratch can be very difficult and awkward, even for a full-time plumber sometimes.

Replacing an outside that has already been fitted is very easy and I would definitely recommend a DIYer to give it a go.

Only you know your level of competence but if you haven’t done any plumbing before then installing an outside tap might be a bit much for you.

Feel free to ask any questions in the comment section below and I’ll try my best to help.

Please share this post if you found it helpful.

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How to Fit an Outside Tap FAQs

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Can I fit an outside tap myself?

Yes, you can fit an outside tap yourself. If you are competent, then fitting an outside tap is definitely doable.

There are no regulations saying you can’t fit an outside tap yourself, it just boils down to competence and confidence.

Can you fit an outside tap anywhere?

Yes. Basically, you can fit an outside tap anywhere. You just need to be able to run a cold water pipe to it. Outside taps are normally fitted on the outside wall behind kitchen sinks but can be fitted anywhere.

How long does it take a plumber to fit an outside tap?

Most of the time it takes less than an hour for a plumber to fit an outside tap.

It can sometimes take a lot longer (2 -3 hours) depending on exactly what needs to be done.

The distance from the water supply where the outside tap is being fitted can be a problem, or the original plumbing might need a lot of adapting to get a new connection onto it, but most of the time (for me) it takes less than an hour for an outside tap installation.