Burst Pipe or Leaking Pipe: What to Do First
Burst Pipes, Leaking Pipes & Water Leaks
Work out what to do first, how urgent the leak is and where the water may be coming from.
A leaking pipe can range from a slow drip under a sink to a major burst line inside a wall or ceiling. The first priority is limiting further water damage and identifying whether the leak is on the pressurised water supply, a fixture connection or the drainage system.
What Kind of Leak Are You Seeing?
Answer four questions to work out the safest first step and which part of the plumbing may be involved.
—
If water is contacting electrical equipment or you believe there is an electrical hazard, keep clear of the affected area and arrange appropriate emergency assistance.
What Should You Do First if a Pipe Bursts?
For a pressurised water-supply leak, isolating the affected fixture or the property water supply can reduce further water loss. Move belongings away from spreading water where safe and avoid electrical equipment in or near the wet area.
After the immediate flow is controlled, the source and damaged section of pipework can be identified and repaired.
Common Types of Household Water Leaks
Not all visible water comes from the same plumbing system. Identifying when and where it appears is one of the best diagnostic clues.
Pressurised Water Pipe Leak
Water can escape continuously because the pipe remains under pressure even when taps and appliances are not being used.
Tap or Mixer Connection Leak
Flexible hoses, isolation valves and connections below sinks and basins can leak from the pressurised water supply.
Waste Pipe Leak
A drainage leak may only become visible when the associated sink, shower, bath or appliance is actually being used.
Pipe Leak Inside a Wall
Water may travel behind wall linings before becoming visible as staining, dampness, bubbling paint or water at floor level.
Ceiling Water Leak
Water through a ceiling can originate from plumbing above, bathroom fixtures, roof water or another source, so timing matters.
Underground Water Leak
A buried water service can leak without the damaged pipe being visible, sometimes producing meter movement, wet ground or unexplained consumption.
What the Leak Pattern Can Tell You
| What Happens | Possible Source | Useful Clue |
|---|---|---|
| Water runs constantly | Pressurised supply pipe or connection | Continues even when fixtures are not used |
| Leak appears when sink drains | Waste pipe or drain connection | Stops when sink is not being used |
| Water appears under mixer | Flexible hose, mixer or isolation valve | Check whether it leaks constantly or only while tap runs |
| Damp wall with meter movement | Possible concealed supply leak | Flow continues with normal water use stopped |
| Ceiling leaks during shower use | Bathroom plumbing or waterproofing area | Timing follows bathroom use |
| Ceiling leaks only during rain | Roof or stormwater source may be involved | Not necessarily a pressurised plumbing leak |
What to Do Before a Plumber Arrives
The goal is damage limitation, not attempting a permanent plumbing repair without the right tools or access.
Isolate Water if Safe
If the leak is on the water supply and the appropriate valve can be safely accessed, isolating the supply can reduce further leakage.
Stop Using the Fixture
If the leak only occurs when a sink, shower or appliance is used, stop using that fixture until the source is known.
Protect Nearby Belongings
Move furniture, stored items and other belongings away from spreading water where it can be done safely.
Avoid Electrical Hazards
Do not touch wet electrical equipment or enter an area where water may have contacted electrical systems.
Note Where Water Starts
Knowing the first visible wet point and what was operating at the time can make diagnosis faster.
Take Photos
Photos of the leak area, affected finishes and visible pipework can help document what happened and how quickly it spread.
How Do You Know if a Pipe Is Leaking Inside a Wall?
Concealed leaks rarely announce their exact location, so several clues need to be considered together.
Damp or Stained Wall
New moisture, bubbling paint or discolouration can indicate water reaching the wall lining from behind.
Water Appears at Floor Level
Water can travel down inside a wall cavity before becoming visible near skirting, flooring or cabinetry.
Meter Moves With Everything Off
Continued metered flow strengthens the case for a pressurised water-supply leak rather than condensation or an old stain.
Water Sounds Behind Wall
A persistent water sound without a running fixture can be another clue when combined with meter movement or dampness.
Problem Changes With Fixture Use
If the leak only appears while a shower or basin is used, drainage or fixture connections may be involved instead of the pressurised supply.
Moisture Persists
Moisture that keeps returning after the area has dried needs a source identified rather than repeated surface repairs.
Water Coming Through the Ceiling: Is It Plumbing?
Water that appears whenever an upstairs bathroom, shower or appliance operates may point toward plumbing, drainage or bathroom-related issues above.
Water that only appears during or after rain may instead point toward the roof, guttering or stormwater system. A constant leak independent of weather and fixture use is more consistent with a pressurised water source.
What Causes Water Under a Sink or Vanity?
Flexible Hose
Flexible water connectors can leak from the hose body or either connection.
Isolation Valve
The local hot or cold isolation valve can leak from its body, spindle or connection.
Mixer Connection
Water can travel down the fixture or supply hoses and collect inside the cupboard.
Sink Waste
Drainage water may only leak while the sink is full or actively draining.
Dishwasher Connection
Kitchen cupboards can also contain appliance water and drainage connections that leak during operation.
Water From Above
Water around the mixer or benchtop can run down into cabinetry and make an under-sink connection look like the source.
Signs of an Underground Water Pipe Leak
Buried leaks can be difficult to locate because water does not always rise directly above the damaged pipe.
Meter Keeps Moving
Continuous metered flow with all normal water use stopped is a strong reason to investigate the water service.
Unexpected Wet Ground
A persistent wet patch without recent rain or irrigation may be a clue, although it does not prove the exact location.
Water Bill Has Increased
Higher metered use without a household usage change can support the suspicion of an ongoing hidden leak.
Pressure Has Changed
A significant leak can sometimes alter how the supply behaves, particularly when combined with other leak indicators.
Water Appears Near Concrete
Buried or under-slab water can travel before it becomes visible, so the first wet point is not always directly above the fault.
Leak Needs Locating
Targeted leak detection may be more appropriate than excavating or opening surfaces based only on a guess.
Water Supply Leak vs Drainage Leak
One of the most useful distinctions is whether the leak occurs continuously or only when water is being used.
Often Continues Constantly
A leak on a pressurised supply pipe can continue even while every tap and appliance is off.
Often Appears During Use
Wastewater leaks often appear when the associated sink, shower, bath or appliance is discharging.
Timing Helps Narrow It Down
Observing exactly when the water starts and stops can be more useful than the visible leak location alone.
What Causes Water Pipes to Leak or Burst?
Age & Deterioration
Pipe materials, joints and fittings can deteriorate over time depending on installation conditions and water exposure.
Corrosion
Some metallic pipework can corrode and eventually develop pinholes, weakened walls or failed joints.
Joint or Fitting Failure
Leaks can originate from connections rather than the main length of pipe.
Physical Damage
Drilling, excavation, impact or building work can damage concealed or underground plumbing.
Movement or Stress
Pipework can be stressed by movement, poor support or conditions around the installation.
Excessive Pressure
Abnormal water pressure can increase stress on valves, flexible hoses, fittings and plumbing components.
How Is a Leaking Pipe Diagnosed and Repaired?
Confirm the Water Source
The first step is separating water supply, drainage, roof water, condensation and other possible sources.
Isolate the Affected Section
Where practical, the relevant water supply is isolated so the area can be inspected safely.
Locate Concealed Pipework
Where the fault is hidden, testing and leak-detection methods can help narrow the likely location before surfaces are opened.
Access the Fault
The required access depends on whether the pipe is exposed, in cabinetry, inside a wall, below a floor or underground.
Repair the Pipe or Fitting
The damaged component is repaired or replaced using a method suitable for the pipe material and location.
Test Before Restoration
The plumbing should be checked before building finishes are fully restored so the repair is not concealed before its performance is confirmed.
When Is a Water Leak Urgent?
The urgency depends on water volume, what is being damaged and whether the leak creates another safety risk.
Water Is Escaping Rapidly
A high-flow leak can damage floors, walls, ceilings and belongings quickly.
Water Is Near Electricity
Keep clear of wet electrical equipment or any area where the leak may have contacted electrical systems.
Ceiling Is Saturated
Heavy water loading can damage ceiling materials and the area below should be treated cautiously.
Leak Cannot Be Isolated
A pressurised leak that continues despite attempts to isolate a local fixture can keep causing damage.
Water Is Entering Building Materials
Prolonged moisture can increase damage to cabinetry, plasterboard, flooring and timber.
Leak Is Getting Worse
A small leak that becomes a steady stream or rapidly expands should be treated with increasing urgency.
Frequently Asked Questions About Burst & Leaking Pipes
What should I do first if a pipe bursts?
If it can be done safely, isolate the affected water supply or property water supply to reduce further leakage. Keep clear of wet electrical equipment and move belongings away from spreading water where practical.
How do I know if a pipe is leaking inside a wall?
Possible signs include persistent dampness, staining, bubbling paint, water appearing at floor level, water sounds and meter movement while normal water use is stopped.
Why is water coming through my ceiling?
Possible causes include plumbing above, bathroom drainage, a pressurised water pipe, roof leakage or stormwater. Whether the leak occurs continuously, during fixture use or only during rain is an important clue.
Why is there water under my sink?
Common sources include flexible hoses, isolation valves, mixer connections, sink wastes, appliance connections and water tracking down from the fixture or benchtop above.
How can I tell a water supply leak from a drain leak?
A pressurised supply leak can continue even when fixtures are not being used. A drainage leak often appears only while the relevant sink, shower, bath or appliance is discharging.
Can a pipe leak underground without showing at the surface?
Yes. Water can travel through soil, below concrete or along other paths before becoming visible, so the surface wet point may not be directly above the fault.
Can a water leak cause a high water bill?
Yes. A continuous supply leak uses metered water for as long as the leak remains active, even when nobody is deliberately using water.
Can a water leak cause low pressure?
A significant leak can affect supply performance. Low pressure combined with meter movement or unexplained water loss should be investigated as part of the wider plumbing system.
Can I just patch a leaking pipe temporarily?
A temporary measure may reduce leakage in some circumstances, but the damaged pipe or fitting still requires a proper repair suitable for the pipe material and installation.
Do all hidden leaks require walls or floors to be opened?
Not immediately. Leak-detection and diagnostic methods can sometimes narrow the likely location first, helping reduce unnecessary destructive access.
Why does the leak only happen when I use the shower?
A leak linked to shower use can involve shower plumbing, drainage or surrounding bathroom systems. A pressurised supply leak is more likely to continue even when the shower is off.
When should I call a plumber for a leaking pipe?
Professional assessment is appropriate when the leak is active, concealed, underground, causing building damage, cannot be isolated, keeps returning or the source cannot be confidently identified.
Still Have an Active or Hidden Water Leak?
Whether the water is coming from an exposed pipe, inside a wall, through a ceiling, under a fixture or from underground, the next step is to identify the water source, limit further damage and repair the actual failed section rather than the visible symptom.