Article
A ceiling stain is not automatically a slab leak
Water in a Los Angeles house follows the joist, the hallway, and gravity. The brown mark on the living room ceiling is often a room away from the pipe that failed. People call that a slab leak because the floor is concrete and the fear is expensive. Sometimes it is. Often the tub upstairs is the one that gurgles, and the ceiling is only where the overflow finally showed itself.
A slab leak, in the sense that matters for the repair, is supply water leaving a line under the concrete while the fixtures are off. A drain problem is used water that cannot get to the street, so it comes back at the lowest opening. They need different tools and different prices. Treating every stain as a slab is how a jackhammer shows up for a clog. Competitors who rank for "slab leak Los Angeles" often skip this split and move straight to a quote for opening the floor. The useful missing piece is the test that says the floor should stay closed.
Three checks before anyone talks about concrete
First, the meter, with every faucet, the ice maker, and the irrigation off. A moving meter is supply. A still meter is not a slab leak, no matter how dramatic the ceiling looks. LADWP tells customers the same first step: movement on the meter with the water shut off means water is passing the meter. A drain can flood a floor without touching that dial, because the water was counted when it came in through the faucet.
Second, which fixture speaks. If the kitchen is the only slow basin, the branch under that sink is the suspect, and that article is standing water in a kitchen sink. If the tub gurgles when the washer runs, or a floor drain rises when an upstairs shower is used, the building drain is the suspect. A slab leak does not wait for the washer. It loses water whether or not anyone is bathing.
Third, hot or cold. A stain that grows only when the hot is run is often the water heater, a shower valve, or a hot line in a wall, not the cold line under the slab. We say which of those three checks failed before we name a repair. If you want the meter test written out on its own, it is in water meter moves when every fixture is off.
The floor you actually have
A lot of the San Fernando Valley is slab on grade, which is why the word shows up in every search. Parts of Pasadena, Santa Monica, and older Los Angeles streets are not. A crawlspace or a raised floor can hide the same stain and a pipe you can see without breaking concrete. A garage can be a slab while the house behind it is framed over a crawl. Guessing from the feel of the living-room floor is how the wrong opening gets priced.
Under a raised floor, the inspection can often end at a joint you can point at. Under a slab, the listening and the moisture tell us an area, not a photograph of the pipe. Even then the first visit marks the area. It does not open the floor. You see the reason, then you decide whether that opening is the job you want.
An upstairs unit in a shared building is the other false slab. The stain on your ceiling may be the shower above you, and your own meter may be still the entire time. Match the test to the unit that was using water. Two owners opening two ceilings for one valve is a common and avoidable expense.
When it really is the line under the slab
If the meter moves, the sound peaks in the floor, and the shutoffs above the slab do not stop the movement, the line under the concrete is in the conversation. Isolation still comes first. A hose bib, a softener, and a toilet that never quite shuts off can all move a meter and live nowhere near the slab. We shut those off and watch. When the movement continues with the house branches closed, the remaining line is the one under the floor or in the yard between the meter and the house. Those are different digs. The house valve tells them apart: if the meter stops when the house valve is closed, the loss is on the house side of that valve. If the meter keeps moving with the house valve closed, the loss is between the meter and the valve. That test is in shutting the house valve.
Opening the slab is the repair. It is not the way we confirm the inspection. If the bill for that opening is large enough that you want to hear about payment options, say so. We do not quote a rate on this page, and we do not open the floor so there is something to finance. The range comes after the mark.
The houses we do this in are in Los Angeles, Van Nuys, Sherman Oaks, North Hollywood, Valley Village, Toluca Lake, Northridge, Glendale, Studio City, Calabasas, Beverly Hills, Woodland Hills, Pasadena, Santa Monica, Porter Ranch, and Santa Clarita. If you are between a stain and a guess, request the free inspection and tell us which floor went wet first, and whether any fixture was running when it did.
What not to do while you decide
Do not cut a hole in the ceiling to "let it drain." The hole you choose is rarely the hole the pipe needs, and it destroys the moisture pattern we use to see which side of the joist is wet. A bucket and a towel are enough until someone looks. Do not keep running the fixture that seems to feed the stain in order to watch it grow. You already have the information that it grows. More water only soaks insulation.
If someone has already scanned the floor and marked an X, bring the mark. We will still run the meter. A mark without a moving meter is a guess, and we would rather disagree with that guess in the driveway than open the wrong bay of concrete.
Questions people ask
Does a ceiling stain mean I have a slab leak?
No. The stain is where water arrived, not where the pipe failed. A still meter points at a drain, a fixture, or an old spill. A moving meter with the fixtures off points at a supply leak, which may or may not be under the slab.
Can a drain backup look like a slab leak?
Yes. A tub that fills from below, or a ceiling that stains when an upstairs shower is used, is often a drain. A drain does not move the water meter, because that water was already counted.
Will you open the slab to check?
Not on the inspection. If the meter, the shutoffs, and the sound agree that the line is under the concrete, we mark the area and explain it. Opening the floor is a repair you approve separately.