Finding the Leak Before You Open Anything
A hidden leak announces itself as a water bill, a damp patch or a sound in a quiet house. Locating it precisely is what keeps the repair small.
Detection first, demolition never. The point is to open one square foot, not one room.
The evidence
What a hidden leak looks like from inside the house
Hidden leaks are found by their side effects. Any one of these on its own might be nothing; two together are worth a phone call.
- A water bill that stepped up and stayed up. Not a seasonal irrigation bump, a step change that persists.
- Running water in a silent house. Stand still late at night with everything off and listen near walls and floors.
- Warm or damp patches on the floor, which on a slab house usually means a hot water line beneath the concrete.
- Pressure that has quietly dropped at showers and taps over a few weeks.
- Staining, bubbling paint or a soft patch on a wall or ceiling, particularly along the run between the water heater and a bathroom.
- A patch of yard that stays green or soggy in dry weather, or water at the kerb near the meter box.
- A musty smell in one part of the house, often the first sign of a crawl space leak.
- The water heater relief valve discharging, or the heater running far more than it used to.
Any two of these together is enough to justify a call. Waiting rarely makes the answer cheaper.
Talk to a Plumber NowDo this first
The meter test you can run yourself in an hour
This costs nothing, takes an hour of doing nothing, and tells a plumber more than any description you could give over the phone.
- Turn everything off. Every tap, the dishwasher, the washing machine, the ice maker, and the irrigation system. Ask the household not to flush.
- Find your meter, usually in a box at the kerb, and lift the lid. Note the full reading, including the small sweep hand or the low-flow indicator, often a small triangle or dial that spins on the tiniest flow.
- If the low-flow indicator is moving at all with the house off, water is leaving the system. You can stop there: you have a supply leak.
- Otherwise wait an hour, touching nothing, and read the meter again. Any change means a leak.
- Now narrow it down. Close the main shut-off at the house and repeat. If the meter still moves, the leak is between the meter and the house, the buried service line. If it stops, the leak is inside.
Write down both readings and the times. That is the single most useful thing you can hand a plumber when they arrive.
Toilets before anything else
A toilet flapper that does not seal is the most common cause of a mysteriously high water bill in any house, and it can be silent. Put a few drops of food colouring in the cistern, wait twenty minutes without flushing, and look in the bowl. Colour in the bowl means the flapper is leaking. It is a cheap part, and finding it saves you a detection visit.
The tools
Four ways a plumber finds what is behind the wall
Listening equipment
Pressurised water escaping through a small hole makes a distinctive noise that carries along the pipe and through the structure. Ground microphones and amplified listening discs let a technician trace that sound to a point, and on slab and buried lines it is usually the primary method. It works best in quiet conditions, which is why detection often happens early in the morning.
Infrared imaging
A hot water leak under a floor or behind a wall creates a temperature pattern that a thermal camera reads straight off the surface. Excellent for hot lines under slabs and for tracing how far water has travelled through a wall cavity; less useful on cold lines, where the temperature difference can be marginal.
Isolation and pressure testing
Sections of the system are isolated and pressurised so the plumber can see which branch loses pressure and which holds. It does not pinpoint the spot, but it narrows the search from a whole house to one run, and it is the method that confirms a leak actually exists before anyone starts cutting.
Video inspection
For drain and sewer lines rather than supply, a camera pushed down the line shows cracks, root intrusion, bellies holding water and collapsed sections directly, and a locator marks the spot and depth from the surface. That is what turns a guess about where to dig into a marked point on the ground.
Where leaks hide
Where the leak usually is, by what your house sits on
Visible, but unwatched
The pipe is right there in the open, so detection is often just a proper look with a good light, staining on joists, one wet patch of soil, rust trails at a support. The catch is that nobody goes down there, so leaks are found months late. This is the cheapest foundation type to diagnose and the most likely to have hidden damage by the time anyone does.
Under the concrete
Supply lines cast into or buried beneath the slab cannot be seen at all, so this is where acoustic and thermal equipment earns its keep. Symptoms are a warm floor patch, running water with everything off, and sometimes a hairline floor crack that stays damp. See slab leak repair.
Mostly reachable
Partial and daylight basements, common on north Georgia hillsides, usually leave runs exposed on the ceiling or along walls, so diagnosis is straightforward. The complications are lines cast into a basement slab and fixtures below the main sewer line that rely on a pump.
The buried service line
Between the meter and the house, and entirely invisible. A green patch in dry weather, water surfacing at the kerb, or a meter that keeps turning with the house valve closed all point here. Clay movement and roots make this a routine Georgia failure. See main water line repair.
The Georgia summer question
Wet pipe is not always a leak
Between June and September we take a lot of calls about wet pipes in crawl spaces that turn out to be condensation. Humid outside air meets a cold supply line and gives up its moisture on the metal. It looks exactly like a leak, it drips like a leak, and it wets the ground under the pipe like a leak.
Three ways to tell the difference before paying anyone:
- Dry the pipe completely and watch it. Water returning evenly along the whole length is condensation. Water reappearing at one joint or one point is a leak.
- Check the meter. Condensation does not consume water. If the low-flow indicator is still with everything off, whatever you are looking at is not the whole story.
- Feel which line it is. Condensation forms on cold lines. A wet hot water line in August is a leak.
If it is condensation, insulating the cold lines usually solves it, and it improves the crawl space environment at the same time.
Next steps
What happens once the leak is located
Detection and repair are different pieces of work, and it is worth knowing which one you are agreeing to. A detection visit ends with a marked location, an explanation of what is leaking and why, and a price for putting it right. You are free to take that and decide.
From there the route depends on where it turned out to be. An accessible crawl space or basement leak is usually a straightforward section replacement the same day. A slab leak means choosing between breaking through the concrete at the marked point or rerouting the line overhead, and the cheaper option is not always the obvious one. A buried service line leak means a repair or replacement outside, and in Georgia clay the digging is the slow part. A drain or sewer leak found on camera leads to a spot repair, a lining, or a section dig.
Whichever it is, the two questions worth asking are: is the rest of this pipe the same age and material, and what caused it. A pinhole caused by high water pressure will be followed by more pinholes until the pressure is dealt with.
One visit to find it, a clear price to fix it, and no work until you say so.
Book Leak DetectionQuestions we get on the phone
Answered plainly
Locating it, almost always, acoustic listening, thermal imaging and pressure isolation are non-invasive and that is the whole point of them. Repairing it may still mean opening a small area, but the difference between opening one marked square foot and exploring a wall is exactly what detection buys you.
On a pressurised supply line in reasonable conditions, good equipment in experienced hands typically gets within a foot or so. Accuracy drops with depth, with thick or heavily reinforced concrete, with background noise, and on very small drips that make little sound. An honest technician will tell you the confidence level rather than mark an X and hope.
Toilets first, a leaking flapper is silent and it is the most common answer. Then run the meter test with the whole house off. Then close the main valve at the house and check the meter again: still moving means the leak is in the buried service line outside, which is invisible by nature and very common in Georgia clay.
It is not usually a same-night emergency, but it should not be left. Water under a slab undermines the fill, saturates the soil, can lift or crack flooring and drives your bill up continuously. Weeks, not months, and if the floor is warm to the touch it is a hot line, which means you are also heating that water endlessly.
No. If a pipe is visibly spraying in a crawl space, you need a repair, not a detection visit. Detection is for leaks that are proven to exist but cannot be seen, under slabs, inside walls, above ceilings, or buried in the yard.
Very often, and it is worth eliminating first. Irrigation lines are shallow, easily damaged, and typically fed downstream of the meter, so a stuck valve or a cracked lateral shows up as household consumption. If your system has its own isolation valve, close it and repeat the meter test.
Water going somewhere it should not?
Find it precisely, fix it small. Tell us what you are seeing and we will get someone out.
(866) 559-0826