A slab leak found with a thermal camera, not a jackhammer
A water bill that had tripled and a warm patch on a tiled floor. Located to within a hand-span, then re-routed overhead instead of breaking the slab.
- Water bill
- Tripled over one quarter
- Detection
- 2 hours
- Concrete broken
- None
- Tiles lifted
- None
What we were told on the phone
Verbatim, near enough. It is usually the most useful thing anybody says all day.
- "Our bill has gone from about two hundred to just over six hundred and we can't find anything. There's a patch in the hallway that's warm under your feet. Two people have looked at it already."
- A warm patch on a floor with a tripled bill is a hot water line under the slab, and it is one of the few plumbing faults that genuinely needs equipment rather than experience. Two previous visits had confirmed there was a leak without ever locating it.
What we found
The meter was turning with the whole house isolated, which put the leak on the property side. Isolating the hot water unit stopped it, which put it on the hot line — that took ten minutes and it halved the search area straight away.
Acoustic listening narrowed it to a three-metre stretch of hallway. The thermal camera then put it inside a 200 millimetre circle, under polished porcelain tile the owners had laid two years earlier.
The pipe was 1960s copper running through the slab, and there was evidence of a second thinning section further along the same run. That mattered: repairing one point in a fifty-year-old buried run means being back for the next one.
What was actually done
In order, including the bits that are not billable.
- 1
Confirmed the leak at the meter with staged isolation, and identified it as the hot line within the first ten minutes.
- 2
Located it acoustically to a three-metre section, then to a 200 mm circle with the thermal camera.
- 3
Presented two options with prices: break out and repair the single point for $980, or abandon the buried run and re-route the hot line through the roof space for $1,680.
- 4
Ran a new insulated PEX hot line through the ceiling to the bathroom and laundry, and capped the slab run at both ends.
- 5
Pressure tested the new run at 1,500 kPa and held it for an hour, then re-checked the meter with everything off. Nothing moving.
What it cost, line by line
Published in full, against the figure quoted before anything started. This is the only proof a plumber can honestly offer.
Quoted before work started
$1,680 quoted after detection, before any pipework
| Item | Detail | Amount |
|---|---|---|
| Leak detection — acoustic, pressure and thermal | Two hours, located to within 200 mm, no floor opened | Amount$460 |
| Hot line re-route — 14 m insulated PEX | Through the roof space to bathroom and laundry, slab run capped both ends | Amount$1,220 |
| Pressure test and certification | 1,500 kPa held for one hour, meter re-checked | Amount$0 |
| Two wall openings, patched | Cut, repaired and set ready for paint | Amount$0 |
| Invoiced | $1,680 | |
Matched the quote. The point of publishing this one is the comparison: the cheaper $980 repair would have been genuine value on a newer pipe and poor value on this one — and the customer got to make that call with both numbers in front of them.
Afterwards
The bill came back to normal the following quarter. Not one tile was lifted, which on a polished porcelain floor laid two years earlier was most of the reason the owners chose the re-route.
They also have a plan for the cold line, which is the same age and in the same slab. Nothing needs doing yet, and we said so rather than quoting it.
What they said afterwards
Pinned to this job, so you can read the review and the invoice it refers to side by side.
- Slab leak detection
“Two other plumbers did not bother calling back. Tapwell answered at nine at night, talked me through turning the water off myself so it stopped getting worse, and were there first thing. Found in two hours what two other blokes had not found in two visits.”
Other jobs, other invoices
- 01WillettonFebruary 2026
Roots through a clay sewer, cut out and relined
Forty years of jacaranda root through a clay line. Jetted clear the same afternoon, cameraed, and the broken section relined without digging up the lawn.
Invoiced$2,190against $2,190 quoted - 02Canning ValeJanuary 2026
Hot water gone on a Sunday, replaced by mid-afternoon
A seventeen-year-old gas storage unit with a rusted-through tank, on the one weekend the house was full. Diagnosed, replaced and certified the same day.
Invoiced$1,750against $1,890 quoted
Want a number like this for your job?
Ring 0491 570 156 and describe it. You get a fixed price before anything starts, and it is the price that ends up on the invoice.
Plumbing Contractor PL 7742 · Gas Fitting GF 3318 · 12 months on workmanship, in writing on every invoice