Leak detection in Cape Town: how to spot a hidden leak, and how we find it

A hidden leak rarely announces itself. By the time you see a damp patch or a shocking water bill, water may have been running into a wall, floor or garden for weeks.

In Cape Town, where water is expensive and many homes have older galvanised or copper pipework under screed, finding a leak quickly and accurately matters. The right approach finds the leak without tearing up half your house, and produces the evidence your insurer needs to approve your claim.

This guide covers the warning signs of a burst or leaking pipe, simple checks you can do yourself, the methods we use to pinpoint leaks, and how following the correct process protects your insurance claim.

Signs you may have a leak or burst pipe

Some leaks are obvious. Most are not. Watch for any of these:

• A water bill that jumps without any change in how you use water.
• Damp patches, bubbling paint or lifting plaster on walls, especially near bathrooms and kitchens or low down on walls.
• Warm spots on tiled or screeded floors. A leak on the hot water line under the floor often shows up as a patch that feels warmer than the rest.
• Lifting tiles, swollen skirtings or cupboard bases that have gone soft.
• Mould or a musty smell in a room that is normally dry.
• The sound of running water when every tap in the house is closed.
• Low water pressure at one or more taps.
• A patch of garden that stays green or soggy in a dry spell, or water pooling on the driveway or pavement.
• Your geyser running more than usual, or the electricity bill creeping up, which can point to a hot water leak.
• Cracks in paving or walls that appear suddenly, caused by water washing out the ground underneath.

One sign on its own may have another cause, such as rising damp or rainwater coming in. Two or more together are a strong reason to test further.

Checks you can do yourself

Before you call anyone, these simple tests will tell you whether you have a leak and roughly where it is.

1. The water meter test

This is the single most useful check.

1. Close every tap in the house and make sure nobody flushes a toilet, runs the washing machine or uses the irrigation.
2. Find your water meter - usually on the pavement near your boundary wall, under a small cover.
3. Take a photo of the reading, or note the small red dial or spinning star (the leak indicator).
4. Wait 30 to 60 minutes without using any water, then check again.

If the numbers have moved or the dial is turning, water is escaping somewhere on your side of the meter. Our guide to a suddenly high water bill goes into more detail.

2. Narrow it down with the stopcock

If the meter moves, close the main stopcock inside your property (often near where the pipe enters the house) and watch the meter again.

• Meter stops: the leak is inside the house, after the stopcock.
• Meter keeps moving: the leak is on the underground line between the meter and the house.

3. The toilet dye test

Leaking toilet cisterns are one of the most common causes of a high bill.

1. Put a few drops of food colouring into the cistern (not the bowl).
2. Don't flush for 15 to 20 minutes.
3. If colour appears in the bowl, the flush valve is leaking.

4. Check the geyser

Look at the geyser overflow pipe outside. A steady drip or constant flow points to a faulty pressure valve or a geyser under strain. Check the ceiling below the geyser for stains too - and read what to do if your geyser bursts.

5. Isolate the hot water

If you suspect a hot water leak under the floor, switch off the geyser and close its cold water inlet valve, then repeat the meter test. If the meter stops, the leak is on the hot water side.

6. Look and feel

Walk the house with a torch. Check under sinks, behind toilets, around the washing machine and dishwasher, and along skirtings. Feel tiled floors with your bare feet for warm spots.

These checks confirm there is a leak. They won't tell you exactly where it is behind a wall or under a floor. That is where professional detection comes in.

How we find hidden leaks

No single tool finds every leak. We combine methods, using each one to confirm the others, so we open up only where the leak actually is.

Pressure testing

We isolate sections of your pipework and pressurise them, then watch a calibrated gauge. A section that holds pressure is sound. A section that drops is leaking. This tells us which line is at fault - hot, cold, a specific branch or the main supply - before we look for the exact spot, and it gives a clear, recorded result for your insurer.

Acoustic leak detection

Water escaping under pressure makes a distinctive sound. Using sensitive ground microphones and listening equipment, we trace that sound through floors, walls and paving to where it is loudest. It works well on pressurised lines under screed, tiles and driveways.

Tracer gas

When a leak is too quiet to hear, such as a slow seep or a pipe deep in the ground, we drain the line and fill it with a safe hydrogen and nitrogen mix. The gas escapes through the smallest opening and rises through concrete, tiles and soil, where a detector picks it up at the surface. It is one of the most accurate methods for pinpointing tiny leaks.

UV dye testing

For leaks from drains, showers, baths, pools or waterproofing rather than pressurised pipes, we introduce a fluorescent dye into the suspect fixture or line. Under UV light the dye shows exactly where water is coming through, for example on a ceiling below a shower. It is a simple way to prove the source of water ingress.

Moisture readings

Using moisture meters on walls, floors and ceilings, we map how far the damp has spread and where it is wettest. The readings help lead us to the source, show the extent of the damage, and give a baseline so drying can be confirmed after the repair.

Our leak detection process

Every job follows the same steps, so nothing is missed and everything is recorded.

1. Listen to you first. We ask what you have noticed, when it started, and what checks you have done.
2. Confirm there is a leak. A meter test and pressure test establish whether water is being lost and on which line.
3. Isolate the section. We split the system into sections and test each one to narrow the search.
4. Pinpoint the location. Acoustic, tracer gas, UV dye and moisture readings are used as the situation needs, each cross-checking the others.
5. Mark and photograph. The leak position is marked, and readings, gauge results and photos are recorded as we go.
6. Open up only where needed. We break into the wall or floor at the marked spot, keeping damage to a minimum.
7. Repair and retest. Once repaired, the line is pressure tested again to prove the fix holds.
8. Report. You receive a written report with the cause, location, method used, photos and readings, ready to send to your insurer.

Getting your insurance claim approved

The process we follow has a 98% insurance claim success rate. That is not luck. Insurers approve claims that are well documented, and reject or delay claims that aren't.

Most household policies cover the resulting water damage from a sudden burst or leak, and some also cover the cost of tracing and accessing it. Wear and tear, or a slow leak left too long, can be excluded - so how the leak is found and recorded makes a real difference. Always check your own policy wording.

What helps your claim:

• Report it promptly. Notify your insurer as soon as you know there is a leak. Delays can be used to argue the damage was preventable.
• Limit further damage. Close the stopcock and switch off the geyser if needed. Insurers expect you to stop the damage getting worse.
• Photograph everything before anything is moved or repaired: stains, damaged floors, cupboards and belongings.
• Keep the evidence. Keep the section of damaged pipe once it is removed. Assessors often ask for it.
• Get a proper report. A detailed plumber's report stating the cause, exact location, detection method, readings and photos gives the assessor what they need to approve the claim.
• Don't rush into repairs without approval unless it is an emergency. Ask your insurer what they need first.

Our reports are written with assessors in mind, and we are happy to speak to your insurer or assessor directly if they have questions.

If you think a pipe has burst: do this now

1. Close the main stopcock to stop the water.
2. Switch off the geyser at the distribution board if the hot water side may be affected, or if water is near electrics.
3. Switch off electricity to any area where water is near plugs, lights or appliances.
4. Move valuables and furniture out of the wet area and start mopping up.
5. Take photos of the damage before you clean up too much.
6. Call your insurer to open a claim, then call a plumber.

Frequently asked questions

Will my insurance pay for leak detection?

Most household policies cover the resulting water damage from a sudden burst or leak, and some also cover the cost of finding and accessing it. Check your policy wording or ask your broker. A detailed leak detection report makes the claim far easier to approve.

Do you have to break walls or floors to find a leak?

Not to find it. Pressure testing, acoustic listening, tracer gas, UV dye and moisture readings locate the leak from the outside. We only open up at the marked spot to make the repair.

Is tracer gas safe in my home?

Yes. We use a mix of mostly nitrogen with a small amount of hydrogen. It is non-toxic, not flammable at that mix, and disperses harmlessly once it leaves the pipe.

Who is responsible for a leak near the water meter?

The City of Cape Town is responsible for the supply pipe up to and including the meter. Everything on your side of the meter is the property owner's responsibility. If the leak is at the meter itself, report it to the City.

Can I have a leak even if I can't see any water?

Yes. Leaks under a slab or in the garden often drain away into the ground and never show on the surface. A rising water bill or a moving meter with all taps closed is often the only sign.