Simple locates, $200–$400
Short runs, decent access, leak confirmed and marked without drama.
Non-Invasive Leak Detection
Find That Leak
Fast Across
Lilyfield
A leak you cannot see is still on the meter, still under the slab, still soaking the wall cavity. We find them with listening gear, thermal imaging and pressure testing, so the repair needs one small hole in the right place, not three big ones in guesses.
- Licence 368473C, fully insured
- Acoustic, thermal & pressure instruments
- Found and fixed by the same crew
How You Find A Leak Without Demolition In Lilyfield
A hidden leak cannot help giving itself away three times over. Escaping water under pressure sings at frequencies acoustic gear can chase along a pipe run; it changes the temperature of whatever it soaks, which thermal imaging paints in false colour through wall sheeting and slab surfaces; and it bleeds pressure from whichever isolated section of pipework it lives on, which a gauge catches cold. One signal suggests; three signals triangulate.
That triangulation is what you are actually buying. Where the readings converge, we mark the floor, and in Lilyfield’s renovated homes, where pipework wanders in ways no council plan ever recorded, that mark routinely sits metres from where anyone would have started digging on instinct. The difference between those two points is the difference between lifting three tiles and re-doing a bathroom.
High water table, and what it hides
Streets sloping toward Iron Cove and the Bay Run drain unevenly, so heavy rain overloads low-lying gullies.
Close to the water the ground is frequently wet regardless of any plumbing fault, which removes the most obvious diagnostic anybody has. Damp subfloor, moisture in the slab edge and standing water in a trench prove nothing here.
So detection near the water leans on isolation and the meter rather than observation, and on tracer gas where a leak is genuinely hidden by ambient groundwater.
A century of pipework, and no plan of any of it
Lilyfield’s older workers’ cottages run on early clay sewers that crack and let roots in after decades underground.
Older homes are a record of everyone who has worked on them. Original runs, a post-war bathroom teed in somewhere unexpected, a laundry added in the sixties, and nothing documented.
That is why detection on a heritage-era property starts by establishing where the pipes actually go. Tracing the layout is half the job and it is the half that prevents opening the wrong wall.
Pressure at the bottom of the hill
Mains pressure rises as elevation falls, and properties low on a slope routinely sit at the top of the acceptable range. Sustained high pressure is a genuine cause of leaks rather than merely a contributor.
If your property is low-lying relative to the surrounding streets and you have had more than one fitting fail, a pressure test costs very little and a limiting valve costs little more. It is the cheapest leak prevention available.
When a drain leak undermines itself
A cracked earthenware line leaking into its own trench washes out the bedding supporting it. Losing support, the pipe sags; sagging, it holds water; holding water, it collects solids and eventually blocks.
Which is why a drain that has begun to block regularly and a drain that is leaking are frequently the same drain at different stages. Finding it early is considerably cheaper than finding it once it has collapsed.
Smell as evidence
A persistent sewer smell around a property with no obvious source is worth investigating properly. It usually means either a dry or failed trap, or a break in a line venting where it should not.
A smoke test finds both quickly, introduce smoke into the system and watch where it emerges. It is unglamorous, cheap, and conclusive in a way that sniffing around is not.
How a leak is actually found
Detection is a process of elimination, not a single instrument. Isolate sections and watch the meter to establish which line is losing water. Listen along it with acoustic equipment for the sound pressurised water makes escaping.
Where that is inconclusive, plastic pipe, deep runs, noisy ground, tracer gas is introduced into the isolated line and detected at the surface. Thermal imaging helps on hot water lines and under floors.
Why we do not just start digging
Because excavation is where the money goes. The plumbing repair on a typical service leak is minor; getting to it is most of the cost, and getting to the wrong place is all of the cost with none of the benefit.
An hour of detection routinely saves several hours of excavation and a great deal of reinstatement. It is the one part of this work where paying for care is unambiguously cheaper.
What it costs in Lilyfield
The standard hunt, $300–$500
First hour with the full instrument kit, acoustic, thermal, pressure, on a typical concealed leak.
Long or awkward traces, $100–$250/hr
Beyond the first hour: extended runs, tight access, multiple suspects to eliminate.
The genuinely hard ones, up to ~$900
Deep slab lines and multi-storey mysteries at the top of Sydney's range.
The repair itself, quoted on evidence
Priced off exactly what the detection proved, fixed before it starts, same crew, same visit, no second call-out.
Compare it with exploratory demolition, which costs more than detection before it has even guessed right once. Figures here are indicative of the 2026 Sydney market rather than a quote from us, you get your own number as a fixed price before any work starts.
How The Hunt Runs
Step 01
Step 01
Verify The Leak Exists
Meter protocol, bills, history. If the evidence says no supply leak, you hear that for free, not a finding fee for nothing.
Step 02
Convict One Line
Section-by-section pressure isolation, hot against cold, run against run, until exactly one line owns the loss.
Step 03
Mark The Centimetres
Thermal and acoustic sweeps along the guilty run until the signals stack on one spot. That mark is where, and only where, we open.
Step 04
One Hole, Done
Access at the mark, section repaired, pressure re-tested, surface closed. A run in terminal condition gets reroute numbers before, not after.
The Dial Moved, Didn’t It?
Then it is real, running, and billing you daily. Detection this week beats discovery through a ruined floor next month.
A standard detection visit generally runs $350-$650 depending on the size of the property and how much isolating is involved. Tracer gas or extensive thermal work sits above that. Market figures for 2026, not a quote, and if the meter test says there is no leak, you are told that rather than sold the rest of the process.
It is elimination, not one instrument. Isolate sections and watch the meter to find which line is losing water, then listen along it with acoustic equipment for the sound escaping water makes. Where that is inconclusive, tracer gas is introduced into the isolated line and detected at the surface.
Very possibly, and it is worth ruling out first. A cistern leaking internally wastes thousands of litres a quarter silently. Put a few drops of food colouring in the cistern, wait twenty minutes without flushing, then look in the pan. Colour in the bowl means the outlet valve is passing, usually a cheap part.
Corrosion works faster in humid, salt-carrying air, and the small parts go first: tap bodies, external fittings, connections around a hot water unit. Many leaks we find on waterside properties are at a fitting quietly corroding in plain sight, and they are the cheapest to fix if caught before they let go.
Yes, and establishing where the pipes actually run is half the job on an older property. Original runs, a post-war bathroom teed in somewhere unexpected, a laundry added in the sixties, tracing the layout is what prevents opening the wrong wall.
Yes, even if the volume looks small. Saturated backfill is what makes retaining walls move, and the plumbing repair is minor compared with what rebuilding a wall costs.
Yes, and it is easy to miss. A cracked drain leaks into the ground continuously without affecting the meter, without a pressure drop, and often with no symptom inside the house. It is found with a camera rather than acoustics, a different method from a pressure leak.
Pinpoint The Leak This Week In Lilyfield
Non-invasive detection, evidence before quotes, and one crew for the find and the fix.
