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How to install an outside tap

By Rebecca Milligan

Access to an outside tap can make it much easier to water your garden, wash a car or fill a paddling pool. We look at what you need to know about getting one installed.
outside tap against blue sky

With the installation of smart meters in many locations, we all have to be careful about how we use water. There are alternatives to using mains water in your garden, such as water butts or other systems for harvesting rain water. However, an outdoor tap can be extremely useful. Check our tips on how to give your garden a new lease of life, or read on for more about installing an external water source.

Which? Trusted trader Ben Margulies, from BeeXpress Plumbing and Heating, told us that installing an outdoor tap is a straightforward job for a plumber, provided you’ve got a water supply close to an outside wall. The ideal situation is if you have a kitchen with the sink on an external wall at the back of the house. If that’s your domestic set-up, it’s a relatively simple matter to drill a hole outside and connect an external tap to the mains under the sink.

If you’d like a Which? Trusted Traders-endorsed plumber to help you with installing an outside tap, you can search our site for plumbers in your area.

Ben told us you should normally expect your plumber to take one to two hours to complete a straightforward installation. It can be quicker, but he always allows a couple of hours just in case it’s difficult to locate the stopcock, or he needs to move furniture to access the pipework. Ben would usually charge £170 for a standard installation, including all the fittings. Costs will vary around the country.

It’s still possible to install an outside tap without an easily accessible water source, but it gets more complicated and more expensive. If the water needs to come from an island in the centre of a room, for example, the pipework will either need to run under the floor or be boxed in, which is a much bigger job. Sometimes your plumber will need to take the water from a main by the front door, which can be a pain if you want to use a hose at the back of the property – but, as Ben points out, at least you’ll be able to wash your car more easily.

Meeting the regulations for outdoor taps

Your plumber will be able to advise you about which tap to install. If you’re buying a tap yourself, always ensure it measures up to British Standards. The regulations stipulate that an outdoor tap must have a check valve installed. This valve ensures the water can flow only in one direction – out from the mains. Water, particularly in a garden or street, can get contaminated with dirt, mud or grit, and the check valve ensures that any contaminants don’t enter the main water supply.

Be careful if you’re buying taps online - they may not have the necessary valve fitted, which would mean they’re not compliant. If you want to be sure you’re buying a tap with the right valve fitted, your best bet is to buy from a plumbers’ merchant, such as B&Q or similar.

A problem-free installation

It’s a good idea to locate your stopcock before your plumber arrives, as this will save time and allow them to get on with installing the pipework and tap. Stopcocks are usually found under a sink, under stairs or sometimes outside the property in a driveway.

It’s always a good idea to know where the stopcock is in your property, and to turn it at least once a year to check that it won’t stick in an emergency. Read this article for more tips on how to look after your plumbing system.

Ben advised that your plumber should aim to install the tap with minimal pipework running along the outside wall. If pipework is left exposed, it will be vulnerable to extremes of temperature, so any pipework outside your property should always be insulated.  

Hot water in all weathers

Many properties already have a cold tap installed outside, but it’s possible to install a hot tap outside too. This is particularly useful for families with young children who want to fill paddling pools – as the British summer sun can’t be guaranteed to warm the water. A hot tap could also be useful for people wanting to wash their car. Ben said he’s had a number of enquiries for this service recently and is able to install a Y-fitting, which means you can use the hot and cold taps like a mixer tap.

If you’re interested in an outdoor tap for your property, you can find a Which? Trusted Trader-endorsed plumber in your area.

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