Leak Detection Costs in SA: Acoustic, Thermal & Tracer Gas Compared
2 June 2026 · Plumbers On Duty Editorial
A hidden leak can waste 30,000 litres a month before you notice. Specialist leak detection finds it without breaking up your floor blindly — here's what each method costs and when to use it.
The four main methods
1. Acoustic correlation (R1,800 – R3,500)
Ultra-sensitive microphones placed on pipework "listen" for the hiss of escaping water. Best for pressurised water mains under tiled floors or slabs. Accuracy ±300mm on a good day.
2. Thermal imaging (R1,500 – R3,000)
Infrared camera shows temperature differences from leaking hot or cold water. Best for under-floor heating, hot-water lines, and damp wall identification. Doesn't work well outdoors or through thick concrete.
3. Tracer gas (R2,500 – R5,000)
Hydrogen/nitrogen mix is injected into the pipe. The gas escapes at the leak and is detected with a surface sniffer. Best for stormwater, drainage and irrigation lines where no pressure exists. Most accurate method — ±50mm.
4. CCTV camera inspection (R1,500 – R2,800)
Pushed-rod camera surveys inside drains, sewers and stormwater lines. Best for identifying blockages, root intrusion, collapses and cracks in drainage pipework.
Which method for which symptom?
| Symptom | Recommended method |
|---|---|
| Water bill suddenly doubled | Acoustic on main supply |
| Damp patch on internal wall | Thermal imaging |
| Wet patch on garden lawn | Tracer gas |
| Drains backing up repeatedly | CCTV inspection |
| Pool losing water | Pressure test + tracer gas |
| Geyser drip tray full | Visual inspection (no specialist needed) |
What you save vs blind excavation
Blind digging to find a leak typically costs R3,000–R8,000 in damaged tiles, screed and reinstatement — often without finding the leak. Specialist detection averages R2,500 and pinpoints to within centimetres.
Verify the contractor
Ask for examples of past detections (photo report). Many "leak detection" outfits in SA are just plumbers with a cheap moisture meter — not the same thing.
Find a vetted leak detection specialist on our directory.