Moisture mapping, extraction and slab drying where a line under a concrete floor has been leaking.
Fastest: call (833) 490-5225. Or send this and we call you back.
A slab leak is a failure in a water line that runs through or beneath a concrete floor, so the water appears as damp flooring, a warm patch or a bill that will not settle rather than as an obvious spill. The restoration side maps, extracts and dries; the pipe repair is plumbing.
Slab leaks are slow news. Instead of a dramatic flood there is a corner of carpet that never quite dries, a tile grout line that stays dark, a faint warmth underfoot on a cold morning, or a water bill that creeps up while nothing in the household has changed. Weeks can pass between the first symptom and anyone naming the cause.
What makes them awkward is that the water is under the floor and the floor is the thing you cannot open casually. It moves through the slab itself and along the underside of flooring, so it often shows up several feet from where the line actually failed, and the damp area and the leak are rarely in the same room.
Two trades are involved and it helps to know which is which. A plumber locates and repairs the failed line, which may mean breaking a section of the slab or rerouting the run. The restoration work is everything around that: measuring how far the moisture has traveled, extracting, drying the slab and the materials on it, and dealing with what the water has already damaged.
The size of the wet area, how long it ran, the flooring type and how much of it has to be released, the days of drying the slab needs, whether the water was clean or from a drain line, and access. Plumbing repair is billed separately by the plumber.
Flooring choice matters more here than in most losses. Carpet and pad come up and go back down readily, while a glued-down or tiled floor over a wet slab is a bigger piece of work and a bigger decision. Time is the other multiplier: a leak that ran for months has pushed moisture deeper into the concrete and further up the wall base, so the drying is longer and the scope wider. The scope and the figure are explained and approved before work starts, and the Torrance water damage cost guide sets out each factor.
Three checks separate it from most other causes: the meter still moving with everything closed, damp appearing at floor level rather than from above, and no fixture or appliance anywhere near the wet area. A warm patch points at the hot-water side.
Rule out the ordinary suspects first. Look under the nearest sink and behind the toilet, check the washer connections and the water heater pan, and look at the wall and ceiling above for a path from higher up. If all of that is dry and the wet area is at the base of a wall or in the middle of a floor, the slab becomes the likely answer and the meter test is the next step.
Slab-on-grade and raised foundations both exist across the city, and we do not publish a figure for how the local housing stock splits between them. Your own property tells you quickly: a crawl space hatch, vents at the base of an exterior wall, or a floor that steps up from the garage all point to a raised floor.
The distinction changes the whole job. On a slab, a failed line is encased in or beneath concrete, the water spreads sideways along the top of the slab, and repair means opening or rerouting. Over a crawl space, the same failure drains downward into the void, where the problem becomes wet soil, damp framing and insulation instead, which is covered under crawl space water damage.
A slab can be dried, but it releases moisture slowly and needs the right conditions rather than more fans. Readings are taken on the concrete itself across several days, because a surface that feels dry can still be giving moisture up into whatever is laid over it.
This is where coastal air tells. In the marine-layer stretch from spring into early summer the outdoor air often holds more moisture than the room does, so the space is closed and the dehumidifier carries the work rather than open windows. Rushing new flooring onto a slab that has not settled is the most common way a repaired slab leak comes back as a flooring failure a few months later.
Through the materials sitting on the slab rather than the concrete itself. Carpet pad, flooring underlay, baseboard, drywall bottoms and cabinet kick panels stay wet in still air. Guidance published by Cal OES, quoting the California Department of Public Health, is to assume mold growth where items stayed wet more than 48 hours.
Because a slab leak runs for weeks before it is noticed, that threshold is usually long passed by the time anyone calls, which is why the first assessment looks at what has to be discarded as well as what can be dried. The same guidance lists carpet, drywall, ceiling tile, fabric, foam, cardboard, paper and particleboard as items to discard where mold is visible, and points you to the local environmental health department. Call (833) 490-5225 if you want a floor measured before you commit to anything.
Keep electrical equipment off a damp floor: a slab leak puts water under flooring and around floor outlets where you cannot see it. Do not take a hammer or a rotary saw to your own slab to look for the line, because supply lines, drains, conduit and post-tension cables can all be in there and some of them are dangerous to cut. Leave hot-water lines alone, as a slab leak on the hot side can carry enough heat to scald. If the water smells, treat it as contaminated, keep children and pets off the floor, and do not run a household vacuum over it.
The simplest test is the meter: with every fixture closed, a dial that keeps moving says water is leaving the system. Isolating the water heater and retesting can tell you whether the loss is on the hot side. That one check saves a great deal of unnecessary investigation.
Readings are taken in a grid over the flooring and the slab, with a thermal camera used to pick up the warmer band a hot-water line produces. The aim is a boundary on paper: where the wet area starts, where it stops and how far it has climbed into the wall base. That map is also what the plumber works from.
Pinpointing and repairing the line is plumbing work, whether that means opening the slab at one spot or rerouting the run overhead. We say plainly which part of the job is theirs rather than taking it on. Hidden leak detection covers the locating stage in more detail.
Water trapped under flooring cannot be dried through it. Carpet and pad are lifted at the affected edge, vinyl or laminate is released where readings require it, and the slab surface is extracted directly. Base trim comes off so the bottom of the wall can be measured and dried.
Concrete gives moisture back slowly, so drying is measured on the slab itself and not only on the materials above it. Air movers and dehumidifiers run against a dry benchmark taken elsewhere in the building, and readings continue daily. New flooring goes down only once those numbers settle, because adhesive and underlay over a damp slab fail again.
The easiest to notice, because the warmth gives it away and the water heater or recirculating pump often runs more than it should. A thermal camera usually shows the line as a warm stripe across the floor. The heat also speeds up the damage to flooring adhesive and to anything organic in contact with the slab.
Quieter and often found later, because there is no warm patch to feel. It tends to be spotted through the meter, a rising bill or damp appearing at a wall base. The volume can be larger before anyone reacts, so the wet area is frequently wider by the time it is mapped.
A failure on the waste side rather than the supply side, so the water is contaminated and the handling changes completely. There is usually a smell, and flow comes and goes with use rather than running constantly. Porous materials it has reached are removed rather than dried, and sewage backup cleanup explains the protective steps involved.
If it's an emergency, call now. For non-urgent slab leak water damage, send the form and we'll call you back.
The local pattern is slow discovery. Houses here are not built with basements, so there is no obvious low point where a leak announces itself, and a line under a slab can lose water for a long time with nothing more to show for it than a warm spot and a bill. In a city of mostly single-story postwar houses, that bill is often the first real evidence.
Two water utilities serve the city, and the boundary matters when a loss is being investigated. Torrance Municipal Water covers roughly 10,350 acres, about 78 percent of Torrance's land, and California Water Service covers the remainder; your bill names yours. Which side of the meter a leak sits on decides who is responsible for the line, and that is worth asking your utility directly rather than assuming.
The dry season hides the symptoms. Between July and October there is next to no rain here, so damp flooring has no weather to blame and a slab leak is easier to recognise for what it is. In the November to March rain season the same damp carpet edge gets written off as a roof or window problem, and a few weeks go by before anyone checks the meter. If the damp follows the weather instead, roof leak water damage is the more likely page.
Moisture inspection, extraction, controlled drying and cleanup for Torrance houses, condos and commercial units.
Meter tests, moisture mapping, thermal imaging and listening equipment to locate a leak inside a wall, slab or crawl space.
Extraction, cavity drying and cleanup after a supply line, fitting or hose fails inside a Torrance building.
Measured drying of framing, slab, subfloor and wall cavities with equipment sized to the room and the coastal air.
Not sure if you're covered? Check your ZIP code.
A water damage quote is built from the category of the water, how much floor and wall took it on, how many days of drying equipment the materials need, how hard the wet area is to reach, and how much content has to be moved.
A leak between the street main and your water meter belongs to the utility that serves your address; a leak on the house side of the meter is almost always yours.
That decision belongs to the plumber doing the repair, and it depends on where the failure is and whether the run can be rerouted instead. The restoration work does not require breaking concrete: it needs the wet flooring released and the slab surface accessible. Where the slab is opened, the patching and the floor reinstatement are quoted as repair work afterwards.
Long-running leaks under a slab are a recognized concern because of what persistent moisture does to the ground beneath, and that is a question for a plumber or a structural engineer rather than a drying crew. What a restoration technician can tell you is how far moisture has traveled through the slab and the materials on it, with readings to back it up.
Because a supply-side slab leak loses water continuously, past the meter, while nothing in the house uses it. A steady climb over consecutive bills with no change in household routine is a strong signal. The confirming test is to close every fixture and watch the meter dial, and to repeat it with the water heater isolated to see whether the loss is on the hot side.
Coverage decisions sit with your insurer under your own policy, and slow, long-running leaks are treated differently by policies than sudden failures. The California Department of Insurance publishes a residential claims guide and takes consumer questions about residential claims. Document the damp area with photographs and readings as early as you can, whatever you expect the answer to be.
Longer than a surface spill, because concrete gives moisture back slowly and the materials above it have usually been wet for weeks. Several days of equipment is typical for a single room, and the readings rather than the calendar decide the end. Damp outdoor air in the marine-layer months can add to that.
Wait for the slab readings. Adhesive, underlay and engineered flooring laid over concrete that is still releasing moisture tend to fail, and the second failure looks exactly like the first one to anyone who was not there. The final readings in the drying log are the document that says it is ready.