Detection & repair · Corona, CA
Most of Corona south of Ontario Avenue is slab-on-grade, and a pipe under concrete leaks for months before anyone sees water. We locate it accurately first, then price the two honest ways to fix it.
Warm patch on the tile, water running with everything off, or a bill that doubled for no reason; those are the three tells.
Located to the foot
Acoustic, pressure and thermal work before any concrete is cut.
Two real options
Open the slab at the leak, or abandon the run and re-route overhead. We price both.
Cause on the record
Pressure, water chemistry and pipe material all get checked, not just the hole.
The signs
A slab leak is a break in a water line running underneath or inside your concrete foundation. Because the concrete hides it and the soil absorbs the water, it can run for months. By the time it shows itself, it has usually been washing fill out from under part of your foundation for a while, which is why this is one of the few plumbing problems worth chasing on suspicion alone.
Shut every tap, appliance and ice maker. Go to the meter at the street and look at the small low-flow dial. If it moves at all over five minutes, you have a leak somewhere on the private side. That single observation makes the phone call much more productive.
Location
Nobody should be opening concrete to search. Location is a separate discipline from repair, and doing it properly is what keeps a slab leak from turning into a demolition project.
You should get a marked location on your floor and a plain explanation of the evidence before any price for repair is discussed. Full detail on the tooling is on our leak detection page.
Two honest routes
There is no universal right answer. There is a right answer for your house, your flooring and the age of your pipe.
01
Cut a small opening at the located point, expose the line, cut out the failed section, replace it, pressure test, then backfill and patch the concrete. Best when the leak is in an accessible area, the rest of the run is sound, and the flooring above can be repaired or matched. It keeps the original layout and is often the least invasive option overall, but it does mean concrete work and a floor repair.
02
Abandon the failed under-slab run entirely and route new pipe up a wall, through the attic and back down to the fixtures it feeds. No concrete is cut. Best when the pipe under the slab is old and pitted, when the leak sits under a kitchen island, a tiled shower or new hardwood, or when there have already been leaks on that line. The trade-off is drywall openings at both ends and pipe in the attic that needs proper insulation and support.
03
Sometimes the third answer is the correct one. If the under-slab copper has already leaked twice, a third spot repair is money spent on a system that is telling you what it intends to do. Re-piping the affected side overhead prices out higher today and lower over five years. See whole-home repiping.
04
Cut a hole and hope. Price the repair before the leak is located. Or recommend the biggest job on the list without showing you the evidence for it, the marked location, the pressure test result, and the condition of the pipe that comes out.
Sequence
Two visits is common: one to locate and price, one to repair. Sometimes it is all one visit.
Meter check and pressure test on both hot and cold. Occasionally the answer is a running toilet or an irrigation valve, and finding that out costs you very little.
Acoustic first, thermal and tracer gas as needed, then the position marked on your floor. You see the reasoning, not just the conclusion.
Material, age, how the run is laid out, static pressure at the house, and whether the water’s mineral load and any stray current are eating the copper. This is what decides repair versus re-route.
Spot repair through the slab and overhead re-route, with what each involves in concrete, drywall, flooring and time. You choose.
Repair or re-route, brought up to pressure and held, and the meter checked again with everything off. That last check is the proof.
Concrete patched and backfilled properly if the slab was opened; drywall openings left clean and documented. You are told plainly which finishing trades you still need, and what to watch for over the next month.
2000s
Era of most slab-on-grade housing south of Ontario Avenue
1
Typical accuracy of good acoustic location
2
Repair routes, both priced before you decide
24/7
Line answered whenever the floor goes warm
Why here
Slab leaks are not evenly distributed across America. They cluster where slab-on-grade construction met aggressive water and high pressure, and Corona has all three.
The growth south of Ontario Avenue, South Corona, Eagle Glen, Chase Ranch, Sycamore Creek, Dos Lagos, Temescal Valley, is overwhelmingly slab-on-grade from the late 1990s onward. Copper supply lines were run in or beneath the pour before the concrete went down. There is no crawlspace, so there is no way to see a line, and no early warning when one starts to weep.
High mineral content combined with the ordinary chemistry of a closed system pits copper from the inside. Add abrasion, a hot line expanding and contracting against concrete or rubbing on rebar thousands of times a year, and the hot side wears through first. That is why the warm spot on the floor is such a common opening symptom, and why softening the water comes up in the conversation about preventing the next one.
The city climbs from roughly 500 feet at the freeway junction to well over 1,000 feet against the Santa Ana Mountains, and the water system is split into zones to serve that range. In the higher zones, static pressure arriving at the house can exceed what residential piping and fixtures are designed for unless the pressure-reducing valve on the main is working. Many are not. Every psi over the limit accelerates every failure mode under your slab, which is why static pressure gets read on a slab leak call even though the gauge has nothing to do with concrete.
Parts of western Riverside County have soils that swell and shrink significantly with moisture. A slab that moves seasonally puts stress on anything rigid cast into it. A leak that saturates one area of subgrade then makes the movement local and uneven, which is how you end up with hairline tile cracks and a door that stopped closing square. This is also the reason slab leaks are not worth living with: the plumbing repair is finite, and foundation consequences are not.
Downtown and Circle City homes from around 1910 are mostly raised-foundation, so true slab leaks are rarer, but many have had slab additions, converted porches or garage conversions bolted on over the decades, each with its own buried run of whatever material was cheap that year. Those transitions are exactly where we find leaks in the historic core.
Straight answers
| Factor | Effect on the job |
|---|---|
| How hard it is to locate | A clear acoustic signal on a single-story tile floor is quick. A quiet leak under a two-story house with hardwood over it takes real detection time. |
| Where the leak sits | Under an open floor is one job. Under a kitchen island, a tiled shower base or new engineered hardwood is another, and it often tips the decision toward re-routing. |
| Repair route chosen | Concrete cutting, backfill and slab patching versus drywall openings, attic pipe, insulation and support. Different costs, different disruption. |
| Pipe condition | Sound copper with one abrasion point is a spot repair. Pitted copper along the run means you are choosing between this leak and the next three. |
| Flooring above | Matching a discontinued tile is sometimes the largest single line on the invoice. Worth saying up front if you have spares in the garage. |
| Cause correction | Reading and, if needed, replacing the pressure-reducing valve is small money that protects everything else. Softening is a bigger decision with a longer payback. |
Nothing is quoted before the leak is located. A price given over the phone for a leak nobody has found yet is a guess wearing a number.
Do not wait on this one
If the meter moves with everything off, or one patch of floor is warm, get it located this week rather than next month.
Detection first, both repair routes priced, and the cause checked before the plumber leaves.
Related work
Coverage
Slab leak FAQs
The meter test settles most of it. Turn off every fixture, appliance and ice maker, then watch the low-flow indicator at the meter. Movement means water is escaping on your side of the meter.
From there, a warm patch on the floor points at the hot side under the slab, while a wet wall, a running toilet or a soaked planter points elsewhere. A plumber isolates hot from cold by pressure test to confirm which system is losing water before anything gets opened.
It can, and that is the reason to act rather than monitor. Water under a slab washes fill out from beneath it and saturates soil unevenly, and parts of western Riverside County have soils that swell and shrink considerably with moisture.
The results show up as hairline cracks in tile, doors and windows that stop closing square, and slab cracking. Plumbing repair is a bounded cost. Foundation work is not.
Only if you choose the spot repair route. Cutting the slab means opening the flooring and concrete at the located point, repairing the pipe, then backfilling and patching.
The alternative is an overhead re-route: the failed under-slab run is abandoned, and new pipe goes up a wall, through the attic and down to the fixtures. No concrete is touched, but you get drywall openings at each end. Both get priced and you decide.
Spot repair if the leak is in an accessible spot, the rest of the run is sound copper, and the flooring above can be repaired or matched. It keeps the system as designed.
Re-route if the pipe is pitted along its length, if there has already been a leak on that line, or if the leak is under a kitchen island, a tiled shower or expensive new flooring. Re-routing costs more up front and often less over five years, because it removes the whole failure mode instead of one instance of it.
Location typically takes one to three hours depending on the house and how loud the leak is. A spot repair through the slab is often a one-day job for the plumbing, plus concrete cure time and separate flooring repair.
An overhead re-route of one line is usually one to two days. Whole-side re-piping is longer, and the plumber will give you a day count before you commit.
Frequently the resulting damage is covered while the pipe repair and the concrete access are not, but policies differ enormously and we cannot advise you on yours.
What helps: the plumber’s written statement of cause and location, photographs before and during, the meter readings, and an itemised invoice separating detection, access, repair and restoration. Ask for that split explicitly.
Three things, usually together. Abrasion, as a hot copper line expands and contracts against concrete or rebar thousands of times a year. Corrosion, from hard water pitting the pipe from inside and sometimes stray electrical current attacking it from outside.
And pressure, in Corona’s higher zones, static pressure above what residential piping is rated for accelerates everything else. That is why the pressure-reducing valve gets checked on a slab leak call.
Yes, though less often. The historic core is largely raised-foundation, so classic slab leaks are rarer there.
But many of those homes have slab additions, enclosed porches or converted garages added over the decades, each with buried pipe of whatever material was current at the time. Those transitions between old and newer construction are exactly where leaks show up in that part of Corona.
Yes, on two fronts. The opening itself erodes and grows, so flow increases, and the volume of saturated subgrade keeps expanding.
Meanwhile you are paying for every gallon on your bill, and a hot-side leak is paying to heat it too. Slab leaks do not stabilise, and they are not a maintenance item to defer.
To a real extent. Get static pressure read and the pressure-reducing valve corrected if it is high, the single cheapest intervention. If the pipe under your slab is copper and the water is chewing at it, a properly sized softener slows the chemistry down.
And if you have had two leaks on the same under-slab line, take that as information. The third one is not a coincidence, and re-routing that line is usually the decision you will wish you had made earlier.
Corona, CA · slab-on-grade specialists
Accurate detection, both repair routes priced honestly, and a plumber who checks the pressure and the water before signing off.
Serving every Corona neighborhood plus Norco, Riverside, Eastvale, Chino Hills, Yorba Linda and Lake Elsinore.