Slab Leak Repair in Westminster, CA: Find the Leak First, Then Fix It

Signs the leak is in the slab, not somewhere you can see

A leak in a wall or under a sink shows itself. A leak under the slab hides, and the clues are indirect.

• The water meter keeps moving with every fixture and the irrigation off.
• You hear running water, a hiss or a trickle under the floor, in a quiet house.
• One patch of tile or wood feels warm underfoot. That's usually the hot line.
• Carpet or a baseboard stays damp, and the cause isn't a pipe you can see.
• Water seeps up through the concrete in the garage or at the edge of the slab.
• The water bill jumps, sometimes to double or triple normal use, with no change in habits.

One sign alone can have other causes. Two or more together, and the slab is the likely spot. Signs of a slab leak ranks them from strongest to weakest.

Before the plumber arrives

More in what to do first.

Finding a slab leak comes before cutting any concrete

A good leak search starts at the meter and the water heater, not with a jackhammer. The plumber separates the hot side from the cold to see which one is losing water, then narrows it down room by room. Acoustic listening picks up the hiss of water escaping under concrete. Thermal imaging shows the heat trail of a leaking hot line. The goal on tile, carpet or wood is one small, marked spot instead of a trench across the living room.

Callers often ask how close the mark will be. That depends on the house, how deep the line sits and how much noise is around it, so ask the plumber how they confirm the spot before opening the floor.

Where it usually is: hot lines running under kitchens and bathrooms fail more often than cold ones, because heat makes the copper expand and rub against concrete and gravel.

Read how it works on slab leak detection.

Three ways a slab leak gets fixed

Once the spot is marked, there are three common repairs. Which one fits depends on the age of the pipe, where the leak sits and whether this is the first leak or the third.

Some plumbers also line pipes with epoxy from the inside. It suits some houses and not others, so ask whether it fits yours.

Why slab leaks are a Westminster problem

Westminster had about 10,800 residents when it became a city in 1957 and about 91,000 by the 2020 census. Most of its houses went up after that, many of them single-story homes built on concrete slabs. Houses from that period commonly have copper water lines run under the slab. After several decades, copper can thin from the inside and wear where it presses against concrete or gravel. Pinholes follow.

Westminster's water comes from the City of Westminster Water Division, a blend of imported water and groundwater pumped from local wells. If pinholes keep appearing, ask the plumber what they see in the pipe they cut out.

The same story repeats next door: 1950s houses in Midway City, 1960s tracts in Fountain Valley, and the neighborhoods of north Huntington Beach built during that city's growth spurt. From the shops of Little Saigon on Bolsa Avenue to the streets south of the 405, the slab under a Westminster house is often older than the people living on it.

Leaks under the driveway, garage or front yard

Not every buried leak is under the house. The service line from the meter to the house runs under lawns, walkways and often the driveway. Callers describe it as "the leak is after the water meter" or "under the concrete of my driveway." The fix may mean saw-cutting a strip of driveway, or replacing the line with a trenchless method where the ground allows. See water line leak repair.

Hot water line leaking under the slab

A warm floor, a water heater that keeps firing and a gas or electric bill that climbs along with the water bill all point to the hot line. It's the most common slab leak and usually the quickest to find. See hot water slab leaks. Small leaks that keep coming back in copper are covered on pinhole leak repair.

What happens when you call this number

This site is a referral line, not a plumbing company. How the line works is explained in full on the about page.

Before work starts, ask any plumber for their California contractor license number and check it at cslb.ca.gov.

Areas covered

• Westminster 92683
• Midway City 92655
• Fountain Valley 92708
• North Huntington Beach 92647, 92649
• Stanton 90680
• Seal Beach 90740

Details for each place are on areas covered.