The warm hallway tile
A 1960s single-story house with a warm strip between the water heater closet and the bathrooms. That pattern points to the hot line under the slab. Close the heater's cold inlet while the line gets traced.
Slab leak detection and repair in Fullerton, CA
Fullerton slab leaks, found before the concrete comes up
Warm tile in the hallway. A meter that turns with every tap closed. We trace the line first, show you where it broke, then put spot repair, reroute and repipe side by side in writing.
Preview site for Fullerton Slab Leak Repair: the phone number shown is a temporary placeholder, and the request form is not connected to a destination yet.
Three valves, ten minutes
Know if it's the slab before anyone shows up
Close three valves in order and watch one dial. The result tells you whether water is escaping, whether it's inside the house, and which line to suspect.
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Water meter
Box near the street
Everything off, lid up, watch the leak indicator for three minutes.
- Turning: water is leaving the system.
- Still: no steady leak right now.
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House shutoff
Where the line enters the house
Close it and watch the meter again.
- Stops: the leak is inside, slab included.
- Keeps turning: look at the line in the yard.
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Heater cold inlet
Top of the water heater
Reopen the house shutoff, close only this valve. Leave the gas alone.
- Stops: likely a hot-side slab leak.
- Keeps turning: check toilets, then the cold side.
Printable version: the meter test worksheet.
A broken pipe under concrete hides well
Most Fullerton tracts went up between the 1950s and the 1970s on slab-on-grade foundations, with copper supply lines laid in the soil before the concrete was poured. Plenty of those lines still carry the house's water today.
Hard water, pressure and a hot line rubbing against gravel thin the pipe a little each year. Once a pinhole opens, water drains into the soil and the floor above can stay dry for weeks.
A five-minute meter test tells you whether water is escaping. Leak location tells you where. Choose the repair after both.
Warning signs
Signs the leak is under your floor
One sign proves little. Two together mean you should run the meter test today.
- Warm tile or concrete in a strip, often between the water heater and a bathroom.
- The meter's leak indicator turns with every faucet, toilet and sprinkler off.
- A bill well above the same months last year, with no change in how you use water.
- Running or hissing water inside a wall or under the floor in a quiet house.
- Damp carpet, swollen baseboards or a musty room with no visible source.
- The water heater fires more often and hot water runs out sooner.
- Fresh cracks in tile, or water along the outside edge of the foundation.
Today
Before you call anyone
- Test
Turn off every tap, appliance and irrigation timer. Lift the meter lid and watch the leak indicator for three minutes.
- Stop it
Water coming up through the floor, or the meter spinning fast? Close the main shutoff where the line enters the house.
- Hot side
Warm floor, nothing surfacing: close the cold valve on top of the water heater. Leave the gas valve alone, and if you smell gas, get out and call 911 or SoCalGas from outside.
- Record
Photograph the floor, the meter reading and the time. Keep your last few water bills with the photos.
- Protect
Pull rugs off wet flooring and keep everyone clear of water near outlets.
- Verify
Ask for a CSLB license number before anyone opens a floor or wall, and look it up at cslb.ca.gov.
Find the leak first. Then decide what gets broken.
Concrete is the expensive part of a slab leak. Locating the break before the jackhammer comes out keeps the opening small, or lets you skip it with a reroute.
Find, then fix
How we find it, then fix it
The work runs in a fixed order: prove the leak, isolate the line, pinpoint the spot, then choose a repair that suits the pipe and the house.
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Confirm the leak
We read the meter with all water off and rule out toilets, softeners and sprinklers, so a stuck flapper doesn't pass for a slab leak.
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Isolate the line
Hot and cold sides get closed and pressure tested separately. The gauge shows which line is losing water, or whether the loss sits outside the house.
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Pinpoint the spot
Acoustic listening, thermal imaging and line tracing narrow the leak to a patch of floor before anyone touches the concrete.
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Choose the repair
You get the options in writing: open the slab for a spot repair, reroute the line through walls or the attic, or repipe when the old lines are worn throughout.
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Repair and test
The new section is pressure tested and the meter read again. Concrete gets patched; tile, wood and carpet usually go to a separate trade.
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Write it down
You keep a record of what failed, where, and what was done. Your insurer will ask for it, and so will the next plumber.
Repair choices
Four ways to fix it, and when each one fits
The right choice depends on where the leak sits, what floor covers it and how the rest of the pipe looks. Ask for the reasoning and the scope in writing, from us or anyone else.
| Approach | What happens | Usually fits | Ask about |
|---|---|---|---|
| Spot repair | We open the slab at the pinpointed leak and replace the damaged section. | One leak, on a line in fair shape, under floor you can reach. | How was the spot located? Who patches the concrete and the finished floor? |
| Reroute | The under-slab line gets capped, and a new one runs through walls, the attic or along the outside. | A leak under cabinets or tile you want to keep, or a hot line likely to fail again. | Where does the new line run? How many wall openings, and who closes them? |
| Pipe lining | An epoxy coating seals the inside of the existing pipe. | Some lines in suitable condition. Plenty of pipes and leaks don't qualify. | Why is my pipe a good candidate? What happens if the lining fails? |
| Repipe | Most or all supply lines are replaced, usually above the slab. | Repeat leaks, corroded galvanized lines, or copper worn throughout the house. | What shows the whole system is worn? Which pipe, and who pulls the permit? |
Deeper comparison: spot repair vs reroute.
Four ways a Fullerton slab leak shows up
The bill that doubled
Nothing looks wet, yet the indicator creeps with everything off. Rule out sprinklers and toilets first. If the meter still moves, the leak sits under the slab or in the line from the meter to the house.
The second leak in five years
One spot repair, then a new leak somewhere else. This is the moment to compare another repair against rerouting or repiping the lines that remain under the floor.
Water at the foundation edge
Damp soil along the slab with no sprinkler nearby. Close the house shutoff and watch the meter: that one test separates a slab leak from a service line leak in the yard.
Guides, worksheets and neighborhood notes
Every page answers one question about leaks under Fullerton slabs.
- Guides
How leaks under a concrete foundation start, how licensed plumbers locate them, and how spot repairs, reroutes and repipes compare for Fullerton's slab-on-grade homes..
- Worksheets
Step-by-step lists you can use at home today: confirm a leak at the meter, shut off the right valve, record what you see and prepare for the first conversation with a plumber..
- Case notes
Illustrative situations, not real jobs or customers, showing how a slab leak is usually confirmed, isolated, located and repaired in homes like those found around Fullerton..
- Neighborhoods
Fullerton and its neighbors share many slab-on-grade homes from the 1950s to 1970s.
ZIP codes served: 92832 (Fullerton), 92835 (Fullerton), 92831 (Fullerton), 92833 (Fullerton).
Also nearby: 92801, 90621, 92805, 90631, 92870, 92806, 90638, 92821, 92802, 92804, 90603, 90604, 90620, 92865, 91748, 90623, 92840, 90680.
Local notes
Slab leaks in Fullerton homes
Fullerton's housing ranges from older homes near downtown to large tracts of 1950s, 60s and 70s slab-on-grade houses across the flats and the hills toward Brea and La Habra. In many of those tract homes, copper supply lines run under the concrete, and some older homes still have galvanized steel lines that corrode from the inside.
Water in Fullerton comes from the city's own water utility and, like much of North Orange County, is a blend of local groundwater and imported water that tends to be hard. Mineral content is one of several factors in pipe wear; pressure, pipe movement and how lines were bedded under the slab matter too.
- Billing questions and meter-side issues go to the City of Fullerton's water utility; check with the city for its current leak and billing policies.
- Find your main shutoff before you need it, and test that it actually turns.
- If the meter moves with the house shutoff closed, the leak may be in the service line outside rather than under the slab.
- Ask any company to confirm that your Fullerton address is in its service area and that its CSLB license is active.
- Ask your insurer what your policy covers for access and water damage before work starts; coverage varies by policy.
Slab leak questions
How do I know if I have a slab leak?
Turn off every fixture, appliance and irrigation timer, then watch the leak indicator on your water meter. If it moves, water is leaving the system. Combined with a warm floor, damp flooring or the sound of running water, a slab leak becomes likely, but a plumber still needs to confirm where it is.
Can a slab leak be found without breaking up the floor?
Usually the location is narrowed down first with tools such as acoustic listening equipment, thermal imaging and line tracing. Concrete is opened only where the leak has been pinpointed, or not at all if the line is rerouted.
Should I shut off my water?
If water is coming up indoors or the meter is moving quickly, close the main shutoff. If you suspect the hot-water line, closing the cold inlet valve on the water heater stops flow to the hot side while leaving cold water on. Leave the gas controls alone.
What is the difference between a spot repair and a reroute?
A spot repair opens the slab at the leak and replaces the damaged section. A reroute abandons the line under the slab and runs a new one through walls or the attic. Which fits depends on the pipe's condition, where the leak is and how many leaks the house has had.
Is a slab leak an emergency?
Water surfacing indoors, water near outlets or a fast-spinning meter needs prompt attention and the main shut off. A slow leak found by a meter test is still worth acting on soon, because water under a slab can affect the soil and flooring over time.
Why do older Fullerton homes get slab leaks?
Many were built in the 1950s to 1970s with copper or galvanized lines under the slab. Age, hard water, pressure and pipe rubbing against concrete or gravel can all contribute to wear.
Does homeowners insurance cover a slab leak?
It depends on your policy. Some policies treat access to the pipe, the pipe repair and resulting water damage differently. Ask your insurer before work starts and keep photos and the plumber's written findings.
Tell us what you're seeing
Where in the house, what the meter did, and since when. Urgent? Call (714) 555-0104.
Next step
Meter still turning?
Close the main if water is surfacing. Close the heater's cold inlet if the hot side is suspect. Write down the reading, then send us the details. Whoever you hire, check their license at cslb.ca.gov first.
Call (714) 555-0104