Start with evidence, not guesswork
A hidden leak does not always leave a visible puddle. A higher-than-usual water bill, a meter that moves while every tap is closed, new damp patches, peeling paint, musty odours or reduced pressure can all justify investigation. Those signs can also have other causes, so the first goal is to isolate the system and gather evidence.
Leak detection may combine a visual inspection, meter and isolation tests, pressure testing and specialist listening or tracing tools. No single method fits every property. The plumber should explain what the test can establish, what remains uncertain and why a particular area needs to be accessed before surfaces are opened.
Once the likely source is found, ask for the detection and repair scopes separately if they are not being completed together. This makes it easier to understand whether the quote covers only locating the leak, exposing it, repairing the pipe and reinstating walls, floors or landscaping.
Signs worth investigating
Unexpected water use
Check the meter with taps, toilets and water-using appliances off. Continued movement may indicate a leak, but the test should be confirmed carefully.
Damp or mould
A spreading mark, soft surface, musty smell or recurring mould can indicate trapped moisture. Electrical hazards and unstable finishes need extra caution.
Pressure changes
A sudden pressure drop can point to a supply-line problem, while one weak fixture may have a local valve, fitting or aerator issue.
Sounds with taps closed
Hissing or running-water sounds can help narrow the search, particularly when they change after the main supply is isolated.
A sensible leak-detection process
- Record the symptoms, meter behaviour, affected rooms and when the issue is most noticeable.
- The plumber checks visible fixtures and isolates sections where the property layout allows it.
- Appropriate tests narrow the source before any proposed opening of walls, floors or external surfaces.
- You receive an explanation of the likely leak location, repair scope, reinstatement responsibility and compliance needs.
What affects the cost?
Detection cost depends on the size and layout of the property, how accessible the pipework is and which tests are needed. A detection fee may not include opening surfaces, repairing the pipe or restoring finishes, so confirm those boundaries before work begins.
- The number of plumbing zones or lines that must be isolated and tested.
- Whether the leak is visible, underground, behind a wall or below a finished floor.
- Specialist tracing equipment, repeat testing or after-hours attendance.
- Repair access, parts and responsibility for reinstating paint, tiles or landscaping.
Ask for the guarantee period in writing. Confirm which parts and labour are covered, how a repeat problem will be assessed, and whether a return visit has any additional charge.
Questions people often ask
What do plumbers charge per hour in South Africa?
There is no single reliable national hourly rate. Ask whether the job is priced by time, as a fixed scope or as a detection fee plus repair. Confirm the call-out, minimum labour period, equipment charges, parts and VAT before approving work.