Outside tap installation: rules and winter protection

An outside tap is one of the most useful things you can add to a house. It makes washing the car, watering the garden and cleaning bikes easy. But it is also one of the first things to freeze in a Sheffield winter, and one of the easiest places for dirty water to get back into your drinking supply. A good installation deals with both.

What the rules say

The Water Supply (Water Fittings) Regulations 1999 set out how plumbing connected to the mains must be installed. They aim to stop contamination of the public water supply and waste of water. Yorkshire Water’s water hardness page refers to these regulations for anything fitted at home.

For an outside tap, the key requirement is backflow protection. If a hose is left in a bucket of soapy water, a pond or a puddle, and the mains pressure drops, water could be sucked back up the hose into your pipes. A double check valve prevents that. Many new outside taps come with one built in. If yours does not, it must be fitted on the pipe.

What a good installation includes

Part	Why it matters
Double check valve	Stops backflow into the drinking water
Isolating valve inside the house	Lets you turn off and drain the tap for winter
Drain point or way to drain the pipe	Lets you empty the pipe through the wall
Pipe through the wall with a slight fall to the outside	Helps it drain and avoids standing water
Tap fixed firmly to the wall	Stops it moving when a hose is pulled
Lagging on any exposed pipe	Slows freezing

Where to put it

• Terraces: the back yard is usually easiest, close to the kitchen pipework. Many Sheffield terraces have the kitchen at the back, so a short run through the wall works well.
• Semis and detached homes: near the kitchen or utility room on the side or back wall, or by the garage for car washing.
• Cottages and farmhouses: often near an outbuilding or yard. Long runs need careful lagging.

Avoid north facing walls and spots exposed to the wind if you can. They freeze first.

Winter on high ground

Outside taps are a classic cause of winter bursts. If water is left in the pipe running through the wall, it freezes and can split the pipe inside the house, where you will not see it until it thaws.

Penistone sits high on the edge of the Pennines, near the moors and Langsett reservoir, and the area gets hard frosts and early snow. The Geography of Sheffield notes that nearby Stocksbridge and Deepcar are often among the first to get snowfall. Our Penistone area page covers other winter risks there.

Before the first frost:

1. Turn off the inside isolating valve.
2. Open the outside tap and let it drain.
3. If there is a drain point inside, open it to empty the pipe.
4. Leave the outside tap open over winter.
5. Fit a foam tap cover for extra protection.

Yorkshire Water’s winter advice also recommends checking taps and pipes in unheated areas. Our post on lagging pipes covers the rest of the house.

Replacing an old outside tap

Many older outside taps have no check valve and no isolating valve, and some leak from the spindle. Replacing the tap and adding both valves brings it up to date. It is a short job if the pipe is accessible.

If an outside tap froze and cracked last winter, check the pipe inside the wall as well as the tap. A split behind the tap can leak into a cavity or a cellar.

Water meters

If you are on a water meter, everything from the outside tap is charged. A dripping outside tap or a hose left running wastes water you pay for. Fixing drips and using a trigger nozzle on the hose helps.

Front or back?

In Sheffield terraces the back yard is usually the better spot. It is close to the kitchen pipework, out of the wind on many streets, and you can see if it starts to drip. A front tap is handy for washing a car parked on the street, but it means a longer pipe run, often through the cellar, and a tap that passers by can use. If you want both, fit a separate isolating valve for each, so you can drain them on their own.

Should you fit it yourself?

Outside tap kits are sold in DIY shops. They usually involve cutting into the mains pipe, fitting a tee, drilling through the wall and fitting the tap and valves. If you are confident with plumbing and the pipe is easy to reach, it is possible. If not, or if the wall is thick stone, a plumber will do it quickly and make sure the backflow protection is right.

Our tap and toilet repairs page covers outside taps along with other small jobs. Tell us where you would like the tap and send a photo of the wall inside and out, and we will tell you what the job involves.