Leaks and slab leaks
Leak and slab leak repair in Laredo, TX
Some leaks announce themselves with a puddle. Others hide in walls or under the concrete slab and show up only on the water bill. Finding the source is most of the job, and modern leak detection usually means far less digging than it used to.
- Water meter test
- Acoustic and thermal leak detection
- Slab leak repair or reroute
- Supply line replacement
Check the meter yourself first
Before anyone opens a wall, the water meter can tell you whether you have a leak and roughly where it is. The test takes about fifteen minutes and costs nothing.
- Turn everything off. Make sure no faucets, toilets, the washer, the dishwasher or irrigation are running, and the ice maker is not filling. Ask everyone in the house not to use water for the next few minutes.
- Find the meter. In most of Laredo the meter sits in a box near the street, sidewalk or alley. Lift the lid carefully; insects, spiders and scorpions like these dark boxes.
- Watch the leak indicator. Many meters have a small triangle, star or dial that spins with any flow. If it moves with everything off, water is going somewhere. You can also write down the reading, wait 15 minutes and read it again.
- Isolate. Close the main shutoff at the house. If the meter stops, the leak is inside the house. If it keeps moving, the leak is likely in the yard line between the meter and the house, or in an irrigation system on that side of the valve.
- Check the toilets. Put a few drops of food coloring in each toilet tank and wait 15 minutes without flushing. Color in the bowl means a leaking flapper, one of the most common hidden leaks there is.
Why leaks are common in central Laredo
ZIP 78040 takes in downtown and some of the oldest residential blocks in the city. Homes there have often been updated a piece at a time over decades: a new kitchen on old galvanized pipe, a bathroom addition tied into copper, a yard line patched with plastic. Joints between different materials and old valves that have not been turned in years are where leaks start.
The water itself adds wear. Laredo draws its water from the Rio Grande, and minerals in the water leave scale on valves, fixtures and water heaters. Scale makes valves stick and seals wear faster. Clay soils that swell when wet and shrink in drought also move pipes under slabs and in yards, which stresses joints.
The public side has the same age problem. After the October 2024 citywide boil water notice, Laredo’s city manager said more than 30% of the city’s water lines are over 50 years old. That is the city’s system, not yours, but it is a fair reminder that many private lines in older neighborhoods are just as old.
Signs of a slab leak
Most homes in Laredo sit on concrete slabs, with supply lines running underneath. A leak there can run for months before anyone notices. Watch for:
- Warm spots on a tile or concrete floor, which often point to a hot water line
- The sound of running water when nothing is on
- Damp carpet, swollen baseboards or a mildew smell with no visible source
- A water heater that runs more than usual or a gas bill that creeps up
- Cracks in flooring or walls, which can come from leaks or from soil movement
- A sudden jump in the water bill, or a meter that never stops
How plumbers find the leak
A plumber typically starts with the same meter test, then pressure-tests the hot and cold sides separately to learn which one is losing water. From there the tools narrow it down:
Acoustic listening
Ground microphones and listening devices pick up the hiss of water escaping under pressure through concrete, tile and soil. An experienced tech can usually narrow a slab leak to a small area this way.
Thermal imaging
A hot water leak warms the slab above it. A thermal camera shows that warm path on the floor, which is fast and needs no contact.
Line tracing
A locator traces where pipes actually run under the slab, which is often not where an old floor plan says they do.
Moisture meters and cameras
For wall and ceiling leaks, a moisture meter maps the wet area and a small inspection camera through a tiny hole confirms the source before larger openings are cut.
The goal is to pinpoint the spot within a small area before breaking any concrete. Ask the plumber how confident the location is and how big the opening will be.
Repair options
Spot repair
The plumber opens a small section of the slab or wall, repairs the pipe and patches the opening. Good for a single, isolated leak in otherwise healthy pipe. Flooring over the opening is usually a separate repair.
Reroute
A new line runs through walls or the attic, bypassing the leaking section under the slab, and the old line is capped. Often chosen when the pipe under the slab is aging or the leak sits under cabinets or expensive tile.
Repipe
Replacing most or all of the supply lines. Considered when there are repeated leaks or the pipe material is failing throughout the house. See repiping and water lines.
| Option | Best when | Trade-offs |
|---|---|---|
| Spot repair | One leak, pipe otherwise sound | Breaks the slab and floor; other weak spots may leak later |
| Reroute | Leak hard to reach, or pipe under the slab is aging | New line in walls or attic; some drywall patching |
| Repipe | Repeated leaks or failing pipe material | Largest job; solves the whole system at once |
Leaks the city may tell you about
Laredo Utilities staff, including meter readers and conservation inspectors, watch for leaks at meters, irrigation systems and backflow devices. Under the city’s water conservation and drought contingency plan, when a leak is found on the private side of the meter, the property owner gets a written warning to repair a controllable leak within 5 days, and a second failure can lead to a citation. If you receive a notice, call a plumber promptly and keep the invoice as proof of the repair.
Leaks in irrigation systems and backflow preventers count too. If the leak is at a sprinkler valve or a backflow assembly, see the backflow and irrigation page.
How much water a small leak wastes
The EPA’s WaterSense program estimates that household leaks in an average home can waste nearly 10,000 gallons a year, and that many common leaks, like a worn toilet flapper or a dripping faucet, are easy to correct. In a city that regularly works through drought stages, that waste is worth stopping even when it causes no visible damage. Our guide to a high water bill in Laredo walks through the usual suspects.
Sources
Official and primary sources used on this page. Rules change, so check the source before acting on a detail.
Questions
Leaks and slab leaks: FAQ
Does homeowners insurance cover slab leaks?
Many policies cover sudden water damage and sometimes the cost of reaching the pipe, but not the pipe repair itself or damage from a long, slow leak. Read your policy and call your agent before work starts.
Can a slab leak damage my foundation?
Water under a slab can soften or move the soil beneath it, and Laredo’s clay soils react to moisture. That is one reason to fix slab leaks promptly.
Is leak detection a separate charge?
Often yes. Ask the plumber how detection is priced and whether it is credited toward the repair.
How long does a slab leak repair take?
A spot repair is often done in a day, with the floor patched afterward. Reroutes and repipes take longer depending on the size of the house.
The meter moves but I see no water anywhere. What next?
Close the house main. If the meter stops, the leak is inside, often a toilet or a slab line. If it keeps moving, check the yard line and irrigation, then call a plumber.
Related
Often part of the same call
Talk to a plumber
Call to reach a plumbing company that serves ZIP 78040 in Laredo.