A pipe that freezes in the loft on Tuesday can be pouring water through your ceiling by Thursday, because the damage usually happens when it thaws, not when it freezes. If you are asking burst pipe what to do in the UK, the answer is in the first ten minutes: stop the water, make the electrics safe and start recording the damage.
When a pipe bursts, turn off the stopcock first, then drain the system, switch off the electrics if water is near them, and photograph everything before you clean up. Then call a plumber and your insurer. Everything else on this page helps you prepare so that those ten minutes go smoothly.
What to do in the first 10 minutes
1. Turn off the water at the stopcock
The main stopcock is a small tap on the incoming water pipe, usually under the kitchen sink, in a utility room or under the stairs. Turn it clockwise until it stops. If it is stiff, work it with both hands. A stopcock that has not been turned in years is the most common reason a small leak becomes a flood.
If you cannot find it, check the front of the house, near the meter, or outside in a pavement box, which may need a water company key.
2. Turn off the heating and let the water drain
Switch off the boiler so it does not fire without water. Open the cold taps, starting at the highest point in the house, and flush the toilets to empty the system. That relieves the pressure on the damaged pipe. If a hot water cylinder is involved, switch off the immersion heater.
3. Make the electrics safe
Water and electricity are a lethal mix. If water is dripping through a ceiling near light fittings, sockets, or the consumer unit, switch off the power at the consumer unit, but only if you can reach it without standing in water. If you cannot reach it safely, stay away and call an NICEIC-registered electrician or your electricity distribution network.
Do not use wet sockets or touch light fittings with water running through them. A ceiling holding water may collapse, so pierce a bulging section only if you can do so safely, with a bucket underneath and from a distance. Otherwise leave it and move out of the room.
4. Contain the water and move valuables
Put buckets and bowls under the drips. Lift furniture and rugs, move electronics and paperwork to a dry room, and use towels to stop water running into other rooms. You are limiting the damage, not clearing up yet.
5. Photograph and film everything
Before you wipe or move anything, take photos and a short video of the burst pipe, the flooded rooms, the damaged ceiling and any affected belongings. This is your claim evidence. Keep the burst section of pipe if the plumber removes it.
6. Call a plumber and your insurer
Many home insurance policies include an emergency helpline that can send a plumber. Check your policy before you book one yourself, because some insurers will only pay for approved contractors or require approval before major work starts.
If you book your own, choose a WaterSafe-approved plumber. Emergency call-outs commonly cost more than a normal visit, especially at night or weekends.
How to thaw a frozen pipe that has not burst yet
If a tap is running slowly or not at all in freezing weather, a pipe may be frozen but intact. Treat it carefully.
Open the tap so that water can flow as the ice melts, and so pressure does not build.
Warm the pipe gently with a hot water bottle, a warm towel, or a hairdryer on a low setting, starting nearest the tap and working back.
Never use a blowtorch or naked flame. It can damage the pipe and joints, and it is a fire risk, especially in a loft with timber and insulation.
Check for leaks as it thaws. Look along the pipe for drips or bulges, and keep the stopcock to hand.
If the freezing is somewhere you cannot reach, such as inside a wall or under a floor, call a plumber rather than trying to force it.
Why pipes freeze, and where
Pipes freeze when they sit in cold, unheated spaces with little water moving through them. The usual places are:
The loft, especially cold water tanks and pipes above the insulation, which is why topping up loft insulation can make freezing more likely if it keeps heat away from the pipes.
Outside taps and external pipes, including pipes to a garage or garden room.
Under floors and in void spaces, such as under kitchen units on external walls.
Empty or unheated houses, where the heating is off for days.
Freezing alone does not usually split a pipe. Ice expands, building pressure between the blockage and the closed tap, and the weak point gives way, often at a joint. The leak starts when the ice melts.
How to prevent frozen and burst pipes
My view: most burst-pipe floods are a failure of preparation, not bad luck. An hour before the first frost, and knowing where your stopcock is, will save you thousands of pounds and a lot of misery.
Know where your stopcock is, and test it. Turn it off and on once a year so it does not seize. Label it.
Insulate pipes and tanks in cold spaces. Foam pipe lagging is cheap and quick to fit. Insulate the cold water tank and its pipes, but leave the space under the tank uninsulated.
Keep the heating on low in cold weather. If you are away, set the heating to come on at a low temperature, around 12 to 15°C, rather than turning it off.
Open the loft hatch on very cold nights so some warmth reaches the pipes, if the house is occupied.
Disconnect outside taps and fit an insulated cover. Turn off the water supply to the outside tap indoors, and open the tap to drain it.
Fix dripping taps and leaks early. A slow drip is more likely to freeze.
Arrange a keyholder if you go away, to check the house regularly.
What to tell your insurer
A burst pipe is one of the most common household claims, and insurers see the same mistakes repeatedly.
Notify them promptly. Check how long your policy gives you.
Tell them what you have done to limit damage, and keep receipts for emergency plumbing, drying and temporary accommodation.
Do not throw damaged items away until the insurer has seen them or you have been told it is fine.
Check the policy for conditions on unoccupied homes. Some policies restrict cover if a property is empty for more than a set number of days, or if the heating was off.
Check the excess. Escape of water claims often carry a higher excess than other claims.
Storing your policy schedule, photos and receipts in one place makes the claim far quicker.
What to do in the next 30 minutes
Find your main stopcock and turn it off and on. Photograph it and save the photo in Home+.
Find your consumer unit, so you know where to switch off the power.
Check the loft: are the cold water tank and pipes lagged?
Look at your home insurance schedule and note the helpline number and the excess for escape of water.
Fit foam lagging to any exposed pipes and disconnect your outside tap.
Keep your stopcock photo, insurance helpline and plumber’s number in Home+, where you can find them in an emergency.
FAQ
Where is my stopcock? Usually under the kitchen sink, in a utility room or under the stairs, on the pipe where the water enters the house. In some homes it is outside, near the meter or in a pavement box.
Should I turn the electricity off if I have a burst pipe? If water is near sockets, light fittings or the consumer unit, yes, but only if you can reach the switch without standing in water. Otherwise call an NICEIC-registered electrician or your network operator.
Can I use a hairdryer to thaw a frozen pipe? Yes, on a low setting and kept moving, with the tap open. Never use a blowtorch or naked flame.
Will my home insurance cover a burst pipe? Most buildings policies cover escape of water, but conditions apply, such as unoccupancy limits, heating conditions and the excess. Check your wording.
How long does a frozen pipe take to burst? It depends on the pipe, the temperature and where the weak point is. The danger is usually when the ice thaws and water flows.
Should I leave the heating on if I go away in winter? Yes, on a low setting. Turning it off completely leaves pipes in cold spaces exposed to a hard frost.
