7 Signs Your Goodyear Home Has a Slab Leak (And What to Do Before You Call)

What a slab leak is and why Goodyear homes are prone to them

A slab leak is a water leak in the supply or drain pipes embedded in or running directly below the concrete foundation of a home. In Goodyear and across the West Valley, the most common type is a pinhole failure in the copper supply lines at slab level, caused by electrochemical corrosion from the region’s 250 to 400 ppm hard water. Homes built from the 1990s through the 2000s have copper supply systems now reaching 15 to 30 years of service in this hard water environment, which is the age range when these failures become common.

The challenging thing about slab leaks is that the leak point is under concrete and sand fill, which means it may not produce any visible water at the surface for weeks. The water migrates through the porous sand layer and dissipates in the soil, or slowly works upward through the concrete to produce discoloration or moisture at the floor surface. In the meantime, the water is doing damage and accumulating on your water utility bill. The signs below help identify a slab leak before the problem becomes visually obvious.

Sign 1: An unexplained water bill increase

The first sign most Goodyear homeowners notice is a water bill that is $20, $30, or more higher than the same month the prior year without any change in usage habits. A pinhole leak losing even a small amount of water continuously, 24 hours a day, adds up to hundreds or thousands of extra gallons per month. At tiered CAP water rates from EPCOR, Global Water, or City of Goodyear, those extra gallons appear on the bill as a step increase into a higher rate tier, making the bill increase more pronounced than the actual gallon count alone would suggest.

Compare your bill to the same month from the prior year rather than the prior month, since seasonal outdoor watering can mask or mimic a leak when comparing adjacent bills. If the year-over-year increase is unexplained, the water meter test below is the next step.

Sign 2: The sound of running water with all fixtures off

A pressurized water line leaking below the slab produces a faint sound that transmits through the concrete and into the home. Many Goodyear homeowners describe it as a hissing, running, or dripping sound that they initially attribute to the water heater, the refrigerator water line, or a fixture. The distinguishing characteristic is that the sound persists even when every fixture, appliance, and hose bib in the home is turned off. If water is audible when everything should be off, it is almost certainly a supply line failure somewhere in the system.

Sign 3: A warm section of floor

When a hot water supply line is the one leaking below the slab, the escaping water warms the concrete directly above it. Walking barefoot across tile or hardwood, a homeowner may notice one area of floor that is notably warmer than the surrounding surface. This warm spot is often the most specific location indicator available before detection equipment is brought in, and it can point to within a few feet of the actual leak location.

Cold water line slab leaks don’t produce this sign. But cold line leaks on the hot side of the water meter do show up as increased water consumption on the bill, since pressurized water is escaping regardless of which line has failed.

Sign 4: Low water pressure at all fixtures simultaneously

A significant slab leak is essentially a large open faucet running continuously below the floor. If the leak volume is substantial, it reduces the available pressure for all other fixtures in the home simultaneously. If you notice that pressure has dropped at every fixture, not just one, and there are no obvious explanations like a partially closed main shutoff, a supply line failure is among the likely causes and warrants investigation.

Sign 5: Moisture, discoloration, or wet spots on the floor

When enough water escapes below the slab, it eventually works its way upward through the concrete or around the perimeter of the slab and appears at the floor surface. Tile grout lines may show moisture staining. Hardwood flooring may cup, buckle, or show discoloration in the affected area. Carpet may have damp sections. These are late-stage signs that indicate the leak has been running long enough to saturate the concrete and sand fill below.

Sign 6: Mold or mildew smell without a visible source

Water migrating through the sand layer below a slab creates a persistently moist environment that supports mold growth in the lower concrete and any organic material at slab level, including wood subfloor sections, wood cabinet bases, and drywall at the bottom of walls. A persistent musty smell in one area of a Goodyear home, without any visible moisture source above slab, often traces back to water accumulation below the floor. If the smell is concentrated and doesn’t clear after ventilating and checking above-slab sources, a slab leak investigation is warranted.

Sign 7: Your hot water runs out faster than it used to

If the failing line is a hot water supply, the water heater may be continuously trying to recover water lost through the leak. This can shorten the effective hot water supply at fixtures, making the hot water run out more quickly than it did when the system was intact. If you notice that showers are running cold sooner than they used to, and there has been no change in household size or usage patterns, a hot water line loss is one explanation worth checking alongside hot water heater condition.

The DIY water meter test

The water meter test is a simple, reliable first step that any homeowner can perform before calling a plumber. Here is how to do it:

Turn off every water fixture inside and outside the home, including dishwasher, washing machine, ice maker, any running toilets, outdoor hose bibs, and irrigation systems. Turn off any appliances that use water automatically. Go to the water meter box at the street and locate the meter. On an analog meter, note the position of the sweep hand and the register numbers. Wait 15 to 30 minutes without using any water. Return to the meter. If the sweep hand has moved, or the register numbers have changed, water is flowing somewhere in the system while everything should be off. A supply line leak is the most likely explanation.

The meter test confirms that a leak exists and is on the supply side of the meter. It does not locate where the leak is. That step requires acoustic, thermal, or electronic professional detection equipment.

What to do when you suspect a slab leak

Do not cut the concrete yourself. The leak location confirmed by listening or by a warm floor observation may be several feet from the actual pinhole in the pipe, since water migrates laterally through the sand fill before appearing at the surface. Professional acoustic and thermal detection can typically locate a slab leak to within 6 to 12 inches without opening the floor. That precision is what makes the repair access cut as small and specific as possible.

Call us to schedule a slab leak detection appointment. We come out with acoustic listening equipment, thermal imaging cameras, and electronic correlators if needed, locate the leak point, and then provide a written repair estimate based on the confirmed location. We do not bill for the slab access until we are confident in the location. See our slab leak detection and repair page for the full process and what to expect.

Slab leak questions

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