A burst does not always mean a dramatic spray
Some pipe failures are obvious, with water pouring from a ceiling or cupboard. Others begin as a small split that only leaks when the pipe is under pressure. Damp patches that enlarge even when no appliance is running, the sound of water behind a wall, an unexplained drop in pressure or a water meter moving while everything is off can all justify investigation. Frozen pipes are a common concern in cold weather, but corrosion, accidental damage and failed joints can cause similar symptoms at any time.
Act on the water supply first
If water is escaping rapidly, locate and close the internal stop tap if it is safe to do so. Open a cold tap afterwards to relieve some pressure in the internal pipework. Keep away from wet electrical fittings and isolate affected circuits if you can do that safely. Moving furniture and possessions away from the leak can reduce secondary damage. Do not spend valuable time trying to make a perfect temporary repair while water continues to flow; stopping the supply and arranging help is the priority.
Hidden pipe leaks can be deceptive
A split beneath a floor may soak insulation or fill a void before the first stain appears. Water can travel along joists and emerge several metres from the actual break. In a concrete floor, the signs may be persistent dampness, unusually warm or cold areas, or unexplained water use rather than visible dripping. Because the route is hidden, cutting into the first damp patch is not always the quickest way to locate the pipe. The pattern of water use and the plumbing layout are important clues.
After freezing weather
A frozen pipe can survive the cold spell without leaking because the ice itself blocks the split. The problem may only become obvious as temperatures rise and the pipe thaws. Outside taps, loft spaces, garages and poorly insulated cupboards are common vulnerable areas. If you suspect a frozen pipe, avoid using naked flames or intense local heat. A controlled thaw and close inspection are safer. Once a split is found, the damaged section should be repaired rather than simply wrapped and forgotten.
How a plumber approaches the repair
The plumber needs to find the failed section, isolate it and decide whether a local replacement is reliable. Modern plastic and copper systems are repaired differently, and access can be the largest part of the job. If the pipe failed because it froze, the surrounding insulation and route should be considered so the same event is less likely to happen again. If corrosion caused the split, the condition of nearby pipework may deserve attention rather than assuming the hole is completely isolated.
What to tell the plumber
Explain whether the water is still flowing, whether you have managed to shut it off and which rooms are affected. Mention recent freezing weather, drilling, building work or any history of leaks in the same area. Photographs of the visible damage help, but a simple sketch of where the nearest bathroom, boiler or stop tap sits can be useful too. For an emergency visit, make clear if ceilings are bulging, electrics are wet or access is difficult so the contractor knows what they are arriving to deal with.
After the immediate leak is under control
Once the water has been stopped, the next question is why the pipe failed. If freezing caused the split, repairing the copper or plastic without improving insulation leaves the same vulnerable section in place. If a screw, nail or recent building work damaged the pipe, the route should be checked before finishes are reinstated. Older metal pipework that has developed a pinhole may also deserve a wider look for corrosion. Ask the plumber to pressure-test the repaired section before it is boxed in again. Keep photographs of the damaged pipe and surrounding area, especially where floors, ceilings or fitted units have been affected. They can be useful when arranging the separate drying and reinstatement work that often follows a serious escape of water.
This page is general guidance about burst pipe signs; the cause in an individual home still needs to be established from the actual installation.