Who to Call for a Slab Leak: Leak-Detection Plumber First, Then Restoration

A slab leak is the one plumbing failure where the right first call is not a restoration company and not a plumber who turns up with a wrench and a flashlight. The pipe is under a concrete floor. Nobody can repair it, or honestly price the repair, until someone has found it, and finding it takes equipment a general plumber may not carry. So the order is different from a burst pipe in a wall: you confirm the leak yourself at the water meter, shut the main, bring in a plumber who does electronic leak detection to pinpoint the line, and then bring in a water damage restoration company for the floors, baseboards and walls the water has been soaking from underneath. People who make only the plumbing call usually learn later that the floor was the larger bill.

Signs It Is a Slab Leak and Not Something Else

Slab leaks show up indirectly, because the water starts out under concrete. The common signs:

• A warm or hot patch on the floor, usually on tile, vinyl or wood, with no heating duct under it. Hot-water lines show themselves first because the heat comes through.
• The sound of running or trickling water when every faucet, toilet and appliance is off.
• A water bill that jumped with no change in how the house is used.
• Damp carpet, lifting vinyl, cupped boards or dark grout lines in a room with no appliance or fixture nearby.
• Lower pressure at the taps than the house used to have.
• Cracks across floor tile or along the base of walls, or doors that have started to stick.
• A musty smell in a room with no plumbing in it.

Rogers Water Utilities in Arkansas lists the same three tells for its customers: a moist, damp or wet spot on the floor, a warm spot on the ground if the leak is in a hot water pipe, and sounds of water dripping or trickling in an unexpected place. One sign on its own can have another cause. Two together, with the meter moving, is a slab leak until a plumber proves otherwise.

Confirm it with the meter test. The EPA's WaterSense program gives the method: check your water meter before and after a two-hour period when no water is being used, and if the meter changes at all, you probably have a leak. Before you blame the slab, rule out the toilets, which the same utility calls one of the most common sources of leaks in a home. A flapper that does not seal will keep a meter creeping all night. If the toilets are sound and the meter still moves with every fixture closed, the leak is in a pipe you cannot see: under the slab, inside a wall, or in the yard between the meter and the house. A warm floor or a sound under the floor points to the slab; a soft, green patch in the yard points to the service line.

Shut the Water Off at the Main

Once the meter confirms it, close the main shut-off, usually where the supply enters the house or at the meter box near the curb. The shut-off guide shows where to look by house type. Water escaping under a slab has nowhere useful to go. It saturates the soil, wicks up through the concrete into flooring adhesive, carpet pad and the bottom of framed walls, and in expansive clay soils it can move the slab itself. Every hour the main stays open adds to the drying job and, in the worst cases, to the foundation repair.

If the warm floor tells you the leak is on the hot side, many plumbers will suggest closing the cold-water inlet valve on top of the water heater instead, which isolates the hot lines while cold fixtures keep working. If you do that, switch the heater off until the plumber has looked at it. If the main will not turn or you cannot find it, call the water utility and ask them to close the curb stop. Rogers Water Utilities, like most utilities, repairs leaks between the main and the meter; everything on the house side of the meter is yours.

Who to Call for a Slab Leak, in Order

1. 1Confirm it with the meter test. Two hours, no water use, two readings.
2. 2Shut the water off at the main. Or isolate the hot side at the water heater if the plumber is hours away and you need cold water.
3. 3Call a leak-detection plumber to locate it. The repair cannot be chosen or priced before this.
4. 4Call a restoration company for what got wet. The flooring and walls are a separate job from the pipe.

Then the insurer, the same day, once everything is photographed. A structural engineer is a fifth call only if the plumber or the restoration company finds that the slab has moved.

Call a Leak-Detection Plumber to Locate It

Ask, before anyone comes out, whether the company does electronic leak detection on slabs. The tools are acoustic listening equipment that hears the pressurized leak through concrete, thermal imaging that finds the warm plume from a hot line, pressure testing that isolates the hot side from the cold side and the slab lines from the yard line, and tracer gas for the leaks the first three cannot find. The slab leak detection and repair guide explains each method. On the slab leak repair cost page, detection runs $100–$600, tracer gas $400–$2,000, and many firms credit the detection fee against the repair if you hire them for it; ask.

Have the plumber mark the location on the floor and put the repair proposal in writing with the method named. The method is the plumber's decision, not yours and not the restoration company's, because it depends on where the pipe runs, what the slab is made of and how old the plumbing is:

Two things change the answer. A post-tension slab has steel cables under tension in the concrete and is not cut, which pushes the job to a reroute or a repipe. And a second slab leak in the same house is the trade's signal that the system is failing, at which point one more spot repair costs about what a repipe does. Working plumbers in slab-leak markets quote whole jobs at $4,500–$14,000, so a figure in that range is not gouging.

Call a Restoration Company for What Got Wet

The plumber fixes the pipe and leaves. What stays behind is the water that has been rising through the slab for days or weeks. It does not drain back down. It sits in the slab, under vinyl and laminate, in carpet pad, in the bottom plate and drywall of framed walls, and under the toe-kicks of kitchen and bathroom cabinets. A floor that looks dry on top can read wet on a moisture meter for weeks, which is why the drying is a measured job and not a fan in the doorway. Who to call for water under flooring explains how that is checked, and a moisture meter lets you see for yourself where the wet area ends.

A water damage restoration company maps the moisture, pulls the flooring that cannot be dried in place, dries the slab and the wall cavities with dehumidifiers and air movers, and records the readings your insurer will ask for. The EPA says wet materials dried within 24–48 hours will in most cases not grow mold, and it names the back side of drywall and the underside of carpet and pad as places hidden mold grows. A slab leak has usually been running longer than that before anyone notices, so the company should check for mold as well as dry. Mitigation for clean supply water runs $3–$7 per square foot, and most residential water damage incidents land at $2,000–$6,000 in total; drying a concrete slab takes longer than drying a wood floor, so the equipment stays longer. Wet drywall: save or replace covers which walls come out.

If the plumber has already opened the slab, the restoration company works around the hole; if the restoration company is first, it can tell the plumber which flooring is already gone. (888) 217-6781 connects you to a plumbing company taking calls in your ZIP.

Plumber or Restoration Company: Who Does What

Neither trade does the other's job, and a plumber's invoice will not include the drywall and paint. The cost page lists drywall repair and paint after a repipe at $1,500–$4,000, separate from the plumbing.

Your Insurer: Same Day, After the Photos

Standard homeowners policies cover accidental discharge of water from a plumbing system, and the standard form pays the cost of tearing out and replacing any part of a building necessary to repair the system, while excluding the system or appliance from which the water escaped. In plain terms: the concrete work to reach the pipe and the water damage are usually the insurer's, the pipe itself is yours. The dispute on slab leaks is always timing, because the same form excludes constant or repeated seepage or leakage of water over a period of weeks, months or years. So the evidence that matters is when it started: the meter readings, the bill that jumped, the date you first felt the warm spot, and dated photos of the floor before anyone opens it. The policy also requires you to protect the property from further damage and keep a record of repair expenses, which is why drying starts before the adjuster visits, not after. Does homeowners insurance cover water damage covers the general rules, and the claim checklist lists what to keep.

What Happens When You Call

(888) 217-6781 is a referral line, not a dispatcher. This is what the call sounds like, so you do not hang up halfway through:

• A short automated menu answers. Follow the short menu.
• Enter the 5-digit ZIP of the house with the slab leak.
• The line goes quiet for about half a minute while it connects you to a plumbing company taking calls in that ZIP. That is normal. Stay on.
• When someone answers, say it is a slab leak, whether the water is off, whether a plumber has located it, and which rooms have wet flooring or walls.

The company gives you an arrival window for your address on the call. What it does and what it charges is between you and them. Ask whether they are IICRC certified and whether they bill your insurer directly.

While You Wait

1. 1Photograph the floor before anyone opens it. Warm spots do not show in a photo, so write the date and the meter readings on paper and photograph that too.
2. 2Keep the main closed except for short periods when you need water, and keep a note of how long it was open.
3. 3Move furniture and rugs off any damp area so the flooring can be metered edge to edge.
4. 4Do not break the slab or pull flooring yourself. The location has not been confirmed, and the insurer wants to see the damage before it is disturbed.
5. 5Do not run the furnace fan or the AC on high to dry it out. It dries the surface, leaves the slab wet underneath, and moves air across any mold already growing.

The slab leak emergency page has the short version of these steps to keep on your phone. If you are not sure it is a slab leak at all, who to call for water damage sorts the other sources.