Signs that point to a leak under the concrete
A slab leak is a break in a pressurized water line that runs under or inside the concrete foundation. Because you cannot see it, the signs show up elsewhere. A water bill that climbs with no change in habits is the most common one.
Other clues include a floor that feels warm in one spot, the sound of running water when every fixture is off, damp carpet or baseboards, and cracked or lifting tile. A hot water line leaking under the slab often makes the floor above it noticeably warm. Water pressure that drops at several fixtures at once also deserves a closer look.
Quick checks before you call
These checks take about fifteen minutes and tell a technician a lot before the visit.
- Turn off every faucet, appliance and ice maker, then look at the water meter. If the low-flow dial or the small triangle keeps turning, water is moving somewhere.
- Close the main shutoff valve at the house and watch the meter again. If it still moves, the leak is between the meter and the house. If it stops, the leak is inside the home.
- Walk barefoot across the floors and note any warm patches. Mark them with painter's tape.
- Listen near water heater closets, bathrooms and the kitchen with the house quiet. A faint hiss or rushing sound is a useful clue.
- Look for new cracks in grout, baseboards that have swelled, or musty smells in a closet or hallway.
- Write down the last three water bills so the jump is easy to show.
Step one and two: confirm the leak and pinpoint it
The visit starts with isolating the system. The technician shuts off water at the house, pressure tests the supply side, and checks whether the hot side, the cold side or both lose pressure. This separates a slab leak from a dripping fixture, a running toilet or an irrigation problem.
Pinpointing comes next, and it saves money because nobody should open a floor on a guess. A leak detection visit uses acoustic listening gear to hear the leak through the concrete. It often adds a thermal camera, which shows the cool or warm trail of leaking water, and sometimes a line locator to trace the pipe route.
Why pinpointing matters more than speed
A miss of two feet can mean a trench in the wrong room. Good locating narrows the work to a patch of floor roughly the size of a doormat.
Ask to see the marks on the floor and the reading that led to them before anyone cuts concrete.
Three ways to fix a leak in a slab-foundation line
The right method depends on how many leaks there are, where the line runs and what the pipe is made of. Here is how the options compare.
| Method | What is done | Best fit | Typical work time |
|---|---|---|---|
| Spot repair | Cut and open the slab over the leak, replace the bad section, close and patch the concrete | One leak in an otherwise sound line | One to two days |
| Reroute | Abandon the leaking line under the slab and run new pipe through walls or the attic to the same fixtures | A line that has leaked more than once, or a leak under a spot that is hard to open | Two to four days |
| Repipe | Replace most or all supply lines in the house, usually with PEX or copper | Several leaks, aging or failing pipe, or a pattern of repeat repairs | Three to five days |
Step three through five: opening, fixing and restoring the floor
For a spot repair, the crew moves furniture, covers the area with plastic, and cuts the slab with a wet saw or a dust-controlled saw. The concrete comes out, the soil is dug to expose the pipe, and the damaged section is cut away. A new piece is joined with fittings, then the line is pressure tested before anything is buried.
Backfill and fresh concrete go in next. Concrete needs time to cure before flooring goes back, so plan on a day or more before heavy use. Tile, wood or carpet replacement is usually a separate job with its own price.
A reroute often costs less than a second spot repair that fails. If the line has leaked once, ask what condition the rest of it is in before choosing.
What a slab leak repair costs
These are typical ballparks for single-family homes and they change with the job. They are not quotes. Access, pipe material, floor finish and how many leaks are found all move the number.
| Job | Typical ballpark |
|---|---|
| Leak detection visit | $150 to $600 |
| Spot repair through the slab | $1,500 to $4,500 |
| Reroute through walls or attic | $2,000 to $6,000 |
| Whole-house repipe | $4,000 to $15,000 and up |
- DetectionFinding the leak is billed as its own visit. Pinpointing with listening gear and a thermal camera typically runs a few hundred dollars.
- Depth and finish aboveTile over a slab costs more to remove and replace than carpet. Cabinets and built-ins add labor.
- Pipe materialCopper repairs use soldered fittings. PEX uses crimp or expansion fittings. Both are routine, but the parts and time differ.
- Number of leaksA second or third leak found during testing often pushes the job toward a reroute or repipe.
- Permits and inspectionSome work needs a permit. Ask the City Building and Fire Safety Department what applies to your address.
Flooring, paint and drywall repair are usually not included in these ranges. The price is stated clearly before work starts, and any change after the floor is open gets a new price before it goes ahead.
What Altamonte Springs homeowners should know about slab leaks
The University of Florida's IFAS Extension notes that the soils of North and Central Florida are typically very sandy. The Florida Geological Survey adds that the entire state sits on carbonate rock. Neither fact says your pipe will fail, but sandy ground drains fast and can shift around a trench after heavy rain, so a repair crew compacts the backfill in layers before the slab goes back.
The city supplies your drinking water and maintains the pipes, valves and meter up to your property. If the meter is spinning and you cannot find the cause, call Water Distribution at (407) 571-8340 to confirm the city side is sound. Then call us for the house side.
Rerouted lines are installed to the Florida plumbing code, whose model is the IPC, which is another reason to ask whether the quote covers a permit.
What to do while you wait for the repair
Turn off the main shutoff at the house if water is visibly pooling or the bill is spiking. Open a faucet at the lowest point in the house to relieve pressure, then close the valve again once flow stops. Move rugs and electronics off wet floors.
Take photos of damp spots and the meter reading for your records. If you have a leak under a rented unit, tell the property manager in writing today. The 24/7 line is open if the floor is flooding or the main will not close.
Repair or repipe: how to decide
One leak in a line that tests sound everywhere else is a good candidate for a spot repair. Pin-hole leaks in several rooms point to a pipe that is wearing out from the inside, and patching them one at a time gets expensive.
If the first leak shows a pattern, a whole-house repipe can cost less over five years than three separate floor openings. A technician can pressure test each branch to see which lines hold. Ask for that result in writing so you can compare options calmly.
Insurance, documentation and dealing with the aftermath
Many homeowner policies cover the water damage from a sudden leak but not the cost of repairing the pipe itself. Policies differ, so read yours or ask your agent before work starts. Keep the detection report, photos and invoices together.
If your home is near Longwood or Winter Springs and you are comparing contractors, ask each one for the same written scope so the prices line up. Our Longwood service area and Winter Springs crews work from the same Altamonte Springs base.
Slab leak repair questions
A spot repair is usually one to two days. A reroute takes two to four days and a repipe takes three to five. Water is off for part of each day, and flooring work comes after the concrete cures.
Often yes. A reroute sends new lines through the walls or attic and leaves the slab alone. It is a common choice when the old line has leaked before or the floor finish is expensive to replace.
It is urgent if water is pooling, the main will not shut off, or the floor is wet near outlets. A slow leak can wait for the next appointment, but the water bill keeps growing, so do not leave it for weeks.
A pressure test and listening gear tell the difference. Warm floor spots, a meter that moves with all fixtures off, and no wet walls all point downward. Only a technician with the right tools can confirm it.
Call the city's Water Distribution Division at (407) 571-8340. It maintains the pipes, valves and meters that deliver water to your property. If the city side checks out, the leak is on your side of the meter and our 24/7 line can send a technician.