Water Main Leak Detection

Signs your underground water supply pipe may be leaking

A buried supply pipe can lose water without leaving an obvious puddle. An unexplained increase in metered water use, a persistent damp patch or reduced pressure can justify an investigation, but none of these alone proves that the main pipe is leaking.

For a useful first check, turn off all taps and stop appliances, irrigation and automatic pool top-ups from drawing water. Let toilet cisterns finish filling, then check whether the meter continues registering consumption. Movement suggests water is still flowing somewhere downstream of the meter; it does not identify the leak's location.

• Compare actual meter readings, not only bill totals: estimated readings or billing adjustments can also explain a higher account.
• Look for wet ground that persists after surrounding areas have dried.
• Check toilets and visible plumbing before assuming the buried pipe is at fault.
• Ask whether neighbours also have low pressure, which may point to a wider supply problem.

What affects the cost of water main leak detection?

The investigation depends on access to the pipework, the length and layout of the supply line, and whether individual branches can be isolated. Paving, building footprints and uncertainty about the pipe route can also affect the work involved. Multiple leaks or complicated connections may need more investigation than a single accessible line.

Fox Plumbing agrees the price upfront, and the call-out fee includes the first hour of work. Most leaks are found within the hour, but this is not a guaranteed completion time. Ask what the agreed scope covers and how any additional work would be authorised.

• Availability and condition of isolation valves.
• Number of branches supplying the house, outbuildings or irrigation.
• Access to the meter and likely pipe route.
• Whether the booking covers detection only or separately agreed repair work.
• Pensioners qualify for a special rate.

Practical checks for Gauteng properties

A supply line may run beneath a driveway, paving or a garden before reaching the house. Share any plans or knowledge of previous pipe repairs when booking. If your property has a storage tank, pressure pump or separate irrigation supply, mention it: these connections matter when working out which section is losing water.

Distinguish a suspected private supply-pipe leak from a municipal-side problem. Report water escaping in the street or around municipal infrastructure to your municipality, and do not interfere with sealed meter fittings. In a complex, involve the managing agent or body corporate if the affected line may be shared.

• Keep the meter, stopcock and likely pipe route accessible.
• Photograph damp patches and record meter readings before the visit.
• Keep people and vehicles away from ground that appears washed out or unstable.
• If water is causing damage, close your property's accessible stopcock if safe to do so; do not force a seized valve.

Why book Fox Plumbing?

Fox Plumbing is based in Benoni and serves the East Rand and greater Gauteng. Owner Evan Pretorius is a qualified registered plumber with more than 20 years of experience and remains on the tools. Fox Plumbing is a member of IOPSA and PIRB, issues Certificates of Compliance (COCs), and every job is insured.

The detection method uses harmless tracer gas and a detector, without digging to find the leak. To book, phone 084 368 1879. Hours are Monday to Friday, 08:00–17:00, with Saturdays by appointment.

• Owner on the tools.
• Price agreed upfront.
• Call-out fee includes the first hour of work.
• Non-invasive detection keeps the search separate from excavation for repairs.

How we do the job

1. 1

   Describe the symptoms and agree the scope

   Explain changes in water use, pressure or ground conditions, and mention tanks, pumps and shared supplies. Confirm the detection scope and price before work starts.

2. 2

   Check the supply arrangement

   The plumber checks accessible connections and isolation points to establish which pipe section needs investigation. Continued meter movement must be distinguished from normal use or another plumbing leak.

3. 3

   Introduce harmless tracer gas

   The pipe section is prepared for testing and harmless tracer gas is introduced. Gas escaping through a fault provides a signal that can be traced from the surface.

4. 4

   Scan with the detector

   The detector is used along the suspected route to locate escaping gas without digging. Most leaks are found within the hour, although access and pipe layout can affect the time needed.

5. 5

   Review the finding and repair requirements

   The detected location guides decisions about access and repair. Confirm any separate repair scope and price before excavation or other additional work begins.

Common questions