Hidden water leaks — inside walls, under floors, or underground — are more common than most Melbourne homeowners realise, and they can run for months before causing visible damage. By the time you notice damp walls or elevated water bills, the leak has often been running long enough to cause structural or mould issues.
How to Check If You Have a Hidden Leak
The Water Meter Test
This is the most reliable DIY test:
- Turn off all water at every outlet in the house (taps, appliances, irrigation)
- Note the current meter reading (write it down, including the red dial or digital display)
- Wait 30–60 minutes with nothing running
- Check the meter again — if the reading has increased, water is moving somewhere in the system and you have a leak
Signs of a Hidden Leak
- Unexplained increase in water bills: Compare consecutive quarterly bills — a significant jump with no change in usage habits is a red flag
- Damp or discoloured patches on walls, ceilings, or floors
- Musty smell in cupboards, under sinks, or from walls
- Sound of running water when nothing is on
- Wet or lush patches in the garden over underground pipes
- Reduced water pressure at fixtures (water is escaping before it reaches you)
- Hot spots on the floor (suggesting a hot water pipe leak under the slab)
What a Plumber Can Do to Find a Hidden Leak
- Pressure testing: The system is pressurised and monitored for pressure drop, which isolates which section of pipe has the leak
- Acoustic leak detection: Specialist equipment listens for the sound of water escaping under pressure through pipe walls
- Thermal imaging: Infrared cameras detect temperature differences caused by water movement or moisture in walls and floors
- CCTV inspection: For suspected drain leaks, a camera shows the internal pipe condition
Common Locations for Hidden Leaks in Melbourne Homes
- Under the slab: Common in Melbourne homes built on concrete slabs in the 1960s–1980s with copper pipes that have corroded
- Flexi hose connections: Behind toilets and under bathroom and kitchen sinks — small drips that run into the cabinet and aren’t noticed
- Garden irrigation connections: Particularly soaker hose systems and subsurface irrigation
- Meter to house connection: The pipe between the water meter and the house is the owner’s responsibility in Victoria
Sedcon Plumbing investigates and repairs hidden water leaks across Melbourne. Call 0468 013 012 | VBA Lic. 120392