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Water Leak Detection

Water Leak Detection near you

Leak detection is the work of finding water that is escaping somewhere you cannot see, and doing it without opening the building to look. It is a diagnostic service rather than a repair service, and the good operators sell you a location and a probability, not a guess.

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Australian housing shapes the problem in a way that is worth stating plainly, because most of the leak-detection writing online is written for countries with basements and freezing winters. Australia builds overwhelmingly on slab-on-ground. The characteristic concealed leak here is not a burst pipe in an unheated crawl space; it is a pinhole or a failed joint in a supply line cast into or buried beneath a concrete slab, or a wet-area failure sending water sideways through a wall plate. Neither announces itself. Both are expensive by the time they do.

The instrument that starts nearly every investigation is the one already on your property. A water meter that keeps moving when every tap, cistern and appliance in the house is off is the cleanest evidence there is that water is going somewhere it should not, and it costs nothing to check. Everything a leak detection technician brings afterwards, from acoustic gear to thermal imaging to tracer gas, exists to turn that fact into a position on a floor plan before anyone cuts concrete.

Symptoms that point to a concealed leak

  • A water bill that steps up without a change in household behaviour, particularly where the increase is steady rather than seasonal.
  • The sound of running water when no fixture is in use, most audible at night when the house is quiet.
  • A warm patch on a tiled or timber floor, which in a slab house is close to diagnostic for a hot water line leaking beneath the concrete.
  • Tiles lifting, drumming or cracking in a line across a floor, or floorboards cupping along a path rather than in a patch.
  • Paint blistering or plasterboard softening low on a wall, often on the opposite side from a bathroom or laundry.
  • An area of the garden or lawn that stays green and soft through dry weather while everything around it browns off.
  • A persistent musty smell in a room with no visible water, which usually means a cavity has been wet for a long time.
  • A hot water system that cycles or a pump that starts periodically when nothing is being drawn.

The detection methods, and what each one is genuinely good at

  • The meter test comes first: isolate the house at the meter tap, note the dials, and establish whether the loss is on your side of the meter at all.
  • Pressure testing isolates sections of pipework and shows which section will not hold, which narrows a whole house to a single run before any listening gear comes out.
  • Acoustic detection listens for the sound a pressurised leak makes through soil, concrete and pipe, and is the workhorse for supply lines under slabs and yards.
  • Thermal imaging finds temperature differences rather than water, which makes it excellent for hot water lines and much weaker on cold ones.
  • Moisture meters and hygrometers map how far moisture has travelled through a building element, which matters for scoping the damage even when the source is known.
  • Tracer gas introduces a safe gas into an emptied line and detects where it surfaces, and it is the method that works when a leak is too small to hear.
  • Drain cameras answer a different question entirely — whether the problem is the sanitary drain rather than the supply — and are covered in the drain guides rather than here.

How a leak detection visit should actually run

A technician who starts by unpacking equipment is working backwards. The visit should begin with questions and with the meter: when did it start, what changed, which fixtures are on which lines, and does the meter move with the house isolated. That single test splits the problem into two very different jobs, because a leak on the water service between the meter and the house is a different excavation from a leak inside the building.

Next comes isolation and elimination. Cisterns, hot water systems, irrigation, evaporative coolers and outdoor taps are all common culprits that cost nothing to rule out, and a good operator rules them out before charging you for detection. What remains is then pressure-tested in sections to find which run is losing water.

Only then does location work start, with acoustic, thermal or tracer gas methods chosen to suit the pipe, the depth and the surface. The deliverable at the end should be a marked position, a stated confidence, photographs, and a written description of what was tested and eliminated. That document is what lets you get comparable repair quotes and what supports an insurance claim. A verbal 'it is somewhere under the kitchen' is not a result.

Where leaks hide in Australian houses

  • Supply lines cast into or buried under a concrete slab, where the leak is silent, the water often tracks along the slab and the repair means either breaking concrete or rerouting the line overhead.
  • The water service between the meter and the house, which is on your side of the meter, is your responsibility, and is the most common source of a large unexplained bill.
  • Wet-area failures behind tiles, where water escapes through a compromised membrane and moves sideways through the bottom plate of a frame.
  • Concealed connections inside walls at mixers, in-wall cisterns and fridge water points, which is why anything plumbed into a cavity should have an isolation valve.
  • Hot water system relief valve lines and tundishes, which discharge legitimately from time to time and are routinely mistaken for leaks.
  • Irrigation and garden lines left pressurised, which are outside the house, usually forgotten, and sometimes the whole answer.
  • Roof plumbing and box gutters overflowing into the building, which produces water indoors that is not a plumbing leak at all.

Who may look and who may repair

Detection itself is diagnostic work, but everything it leads to is licensed. Repairing a water service, a supply line, a wet area connection or a sanitary drain is licensed plumbing work in every Australian state and territory, and the finished job should produce the compliance certificate that your state's scheme requires. Australia is considerably stricter here than the United Kingdom, where a great deal of domestic plumbing is unregulated, so a technician who offers to open up a pipe himself without a plumbing licence is a warning sign rather than a saving.

Two other boundaries are worth knowing before you book. First, the meter marks a change of ownership: the water authority's asset is on one side and yours is on the other, and the authority will not pay for work on your side. Second, excavating in a street verge or nature strip, or anywhere near a buried service, engages the utility's own rules and the national before-you-dig process. If the detection points outside your boundary, the conversation moves to the water authority before it moves to a digger.

What changes the price of finding a leak

  • Whether the meter test has already narrowed the problem, which can cut an hour of elimination work out of the visit.
  • The surface over the leak, because listening through a bare slab, a tiled floor, a driveway and a garden bed are four different jobs.
  • The depth and material of the pipe, since some materials transmit leak noise well and others barely at all.
  • Whether the water is hot or cold, because a hot line gives thermal imaging something to find and a cold one usually does not.
  • How much of the house has to be isolated and re-pressurised section by section to narrow the run.
  • Whether a written report with photographs is included, which most insurers will expect and which is worth paying for separately if it is not.
  • Whether access requires lifting floor coverings, moving joinery or getting into a roof space, all of which are time rather than skill.

Catching the next one early

  • Read your meter on the same day each month and write the number down; a trend is far more informative than a single bill.
  • Do a five-minute isolation test twice a year: turn everything off, watch the meter, and note whether it creeps.
  • Fit isolation valves at anything plumbed into a wall or under a bench so a future leak can be stopped without shutting down the house.
  • Check the tundish or relief drain of the hot water system occasionally, so you know what normal discharge looks like for your system.
  • Look at the garden after a dry fortnight; a green patch that survives without watering is a leak until proven otherwise.
  • Keep a copy of any detection report with the house papers, because the next technician will save you money by knowing what was already eliminated.

Water Leak Detection: frequently asked questions

How do I check for a leak myself before calling anyone?

Turn off every tap, make sure no cistern is filling, no washing machine or dishwasher is running, the irrigation is off and nobody is about to use water. Then read your water meter, wait half an hour with the house untouched, and read it again. If the reading has changed, water is leaving the system somewhere. If it has not, repeat the test overnight, because very small leaks need a longer window. This costs nothing, takes almost no effort, and is the single most useful piece of information you can hand a leak detection technician.

Can a leak under a concrete slab really be found without breaking the slab?

Usually, yes, and that is the entire point of hiring a detection specialist rather than going straight to a concrete saw. Acoustic equipment can hear a pressurised leak through a slab, thermal imaging will often show a hot water line clearly, and tracer gas will find leaks too small to hear. None of it is infallible, and a good operator will tell you their confidence rather than promising certainty. What you are buying is a much smaller hole in a much better place.

Who is responsible for a leak in the pipe between the water meter and my house?

You are. The water meter marks the boundary between the water authority's asset and yours, and the service pipe running from the meter to the house is the property owner's responsibility to maintain and repair in every Australian jurisdiction. That is why an unexplained bill increase so often turns out to be here: the pipe is buried, nobody inspects it, and the water simply soaks away. Some water authorities operate concession or allowance arrangements for concealed leaks on the customer's side, so it is worth asking yours what applies before you pay the bill.

Will my insurance cover a concealed water leak?

It depends heavily on the policy and on how long the leak has been running. Home policies commonly respond to damage caused by a sudden escape of liquid while excluding damage that has built up gradually over time, and they frequently distinguish between repairing the pipe itself and repairing the damage the water did. This is exactly why a dated, written detection report with photographs matters: it is evidence about when the problem was identified and what was actually found. Read your own product disclosure statement rather than relying on what a contractor tells you.

Is leak detection something an unlicensed technician can do?

The detection itself is diagnostic work, but the repair that follows is licensed plumbing work everywhere in Australia, and so is anything that involves opening the pipework. In practice the sensible arrangement is either a licensed plumber who also does detection, or a detection specialist who works alongside one. Ask who will actually carry out the repair and what compliance certificate you will receive for it. If nobody in the conversation can answer that, you have a detection service and no plan for what happens next.

Sources

  1. ABCB Housing Provisions, Part 10.2 Wet area waterproofing (NCC 2022)
  2. NCC Navigator: Waterproofing in houses

Written by the LokalMatch editorial team. Last reviewed 22 September 2026. How we write and check our guides

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What affects the cost of leak detection

Prices depend on the details of your project. We only publish price ranges when they’re backed by real LokalMatch quote data or reliable sources. Until then, here’s what usually changes the price:

  • Type of problem and how easy it is to find
  • Access to pipes behind walls, under floors or underground
  • Parts and fixtures chosen
  • Age and material of the existing pipes
  • Emergency, evening or weekend service
  • Permits and inspections, where required

How to compare plumbers before you hire

  • Hire a plumber who is licensed for this work in your area, especially for gas water heaters, sewer lines and new plumbing.
  • Ask whether they charge a flat rate or by the hour, and what the call-out fee covers.
  • For leaks and drain problems, choose someone who explains the cause and doesn't only clear the symptom.
  • Get the scope in writing for larger jobs such as a water heater, sewer repair or re-piping.
  • If it's urgent, ask how soon they can arrive and whether after-hours rates apply.

Questions to ask plumbers before you hire

  • Are you licensed for plumbing work in my area?
  • Do you charge a flat rate or by the hour, and is there a call-out fee?
  • What do you think is causing the problem?
  • Will this work need a permit or an inspection, and who will arrange it?
  • Will you need to open walls, floors or the yard to reach the problem?
  • What warranty do you offer on parts and labour?

When to call a pro for leak detection

  • An active leak: shut off the main water valve if you can reach it safely, then call a plumber.
  • Sewage backing up into drains or the basement
  • No hot water, or water pooling around the water heater
  • Pipes that may have frozen during a cold snap

Leak detection permits and local rules

Some leak detection work needs a permit or has to meet local bylaws. Rules vary by municipality, so ask your pro whether a permit is needed and who will apply for it — and check with your city or town if you’re unsure.

Permits and licensing

Seasonal maintenance

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