The leaks that cost the most are the ones nobody saw. They run inside a wall, under a slab or above a ceiling for weeks, and by the time the stain shows up the drywall is soft and the mold has moved in. Here is what to look for, and a five-minute test that catches most of them.
- A musty smell, a jump in the water bill, or a stain that keeps growing are the three most reliable early signs.
- Cupped hardwood, soft baseboards and bubbling paint mean water has been there a while.
- A five-minute check at the water meter tells you whether something is leaking right now.
- In Georgia homes the usual hiding places are attic HVAC and water heaters, crawl spaces, slab plumbing, and the wall behind the shower.
- Finding it early keeps the job to drying; finding it late means demolition and often an excluded claim.
Hidden water damage usually announces itself as a musty smell, a water bill that rose without explanation, stains or discoloration on ceilings and walls, paint that bubbles or peels, floors that cup or feel soft, baseboards or drywall that give under a thumb, mold spots in corners, condensation and high humidity, or a water meter that keeps turning when everything is off. Check the attic, crawl space, under sinks and behind appliances first.
The nine signs
- A musty or earthy smell. Especially when the HVAC first starts, or when you open a closet, cabinet or the basement door. Mold needs about 48 hours of moisture to start, so the smell means water has been there at least that long. How fast mold moves in Georgia.
- A water bill that jumped. Compare this month with the same month last year. A slab leak or a running toilet can add thousands of gallons. Gwinnett, Cobb, DeKalb and Fulton all show usage history online.
- Stains and discoloration on ceilings and walls — yellow or brown rings, a gray shadow at the base of a wall, a dark patch that spreads after rain or after someone showers upstairs.
- Paint or wallpaper that bubbles, peels or cracks. Water behind the surface pushes the finish off. Bubbled paint on a ceiling may be holding water — do not poke it.
- Floors that changed. Hardwood that cups (edges higher than the center) or crowns, laminate that swells at the seams, tile grout that cracks or tiles that sound hollow, vinyl that lifts.
- Soft drywall or baseboards. Press a thumb along the bottom foot of a wall near a bathroom, kitchen or exterior door. Drywall should not give. Baseboards that are swollen, separating from the wall, or have a tide line were wet.
- Visible mold in corners, along window sills, under sinks, on the back of furniture against an exterior wall, or at the bottom of a closet.
- Condensation and humidity. Windows that sweat in winter, a basement that reads above 60 percent on a cheap hygrometer, or a crawl space that smells like a creek bank. Not a leak, but the same result.
- The meter keeps turning. The test below.
The five-minute meter test
- Turn off every faucet, the irrigation system, the ice maker and anything that uses water. Make sure no toilet is running.
- Find the meter box at the street or the property line. Lift the lid (a flathead screwdriver helps) and look at the dial. Most meters in metro Atlanta have a small leak indicator — a little triangle, star or wheel — that spins when any water is moving. Newer digital meters show a flow rate or a dripping-faucet icon.
- If the indicator is moving or the digits are advancing with everything off, water is leaving the system somewhere between the meter and your fixtures.
- Now close the main shut-off at the house. If the meter stops, the leak is inside the house. If it keeps going, it is in the service line between the street and the house — often a yard that stays soggy in one spot.
- Check the toilets by putting a few drops of food coloring in each tank. Color in the bowl after 15 minutes means a flapper is leaking, which is a cheap fix and a common culprit.
A leak the meter cannot see: rain coming in through a roof, flashing or window, HVAC condensate, and a failed drain line are not on the supply side, so the meter sits still. For those, the signs above and a moisture meter are the tools.
Where water hides in a Georgia house
Every region has its typical leaks. Metro Atlanta’s come from how the houses are built.
| Location | What leaks | What you see first |
|---|---|---|
| Attic | Water heaters and HVAC air handlers installed in the attic; condensate drain lines and drain pans clog or rust through; supply lines freeze | A ceiling stain that grows in summer (condensate) or appears after a freeze; a bathroom fan that drips |
| Crawl space | Supply and drain lines, duct condensation, ground moisture through a missing vapor barrier | Cupped hardwood, musty smell, a floor that feels cool and soft, insulation hanging from the joists |
| Under the slab | Copper supply lines run under the slab in many 1960s–80s homes in Cobb, DeKalb and Gwinnett; they pinhole | A warm spot on the floor, a water bill that jumped, the meter turning, a sound of running water in the quiet |
| Behind the shower and tub | Failed grout and caulk, cracked pans, loose valve connections | Soft drywall on the other side of the wall, a stain on the ceiling below, loose tiles |
| Under the kitchen sink and dishwasher | Supply lines, the dishwasher inlet, the garbage disposal gasket | Swollen cabinet floor, warped toe-kick, a laminate floor that lifts at the dishwasher |
| Behind the refrigerator and washer | Ice-maker line and washing machine hoses, the two most common sudden floods | Nothing until it fails; check the hoses yearly and replace rubber with braided steel |
| Windows and doors | Failed flashing and caulk, especially on the weather side; brick veneer without weep holes | Stains at the corners of windows, soft sill, peeling paint below a window |
| Roof | Flashing at chimneys, vent boots, valleys; nail pops; wind-lifted shingles | Attic staining on the sheathing, a ceiling stain that grows with rain |
| Basement walls | Groundwater through block, cracks and the wall-floor joint | Efflorescence (white powder), a damp line at the base of the wall, carpet that smells after rain. More on basements. |
What to do when you find it
- Stop the water. Shut the fixture valve or the main, or have a plumber find the leak. A slab or service-line leak needs leak detection equipment, which plumbers have.
- Photograph everything before any repair, including the leak itself once it is found.
- Find out how far the water went. A moisture meter reads through drywall and flooring without opening them; thermal imaging shows cool, wet areas on walls and ceilings. The damage is almost always larger than the stain.
- Dry it properly. If it reached drywall, insulation, subfloor or cabinets, household fans will not do it. Professional drying brings the materials back to a verified dry standard.
- Remove what is already compromised. Drywall and wood with mold growth, swollen particleboard, saturated insulation. Our mold remediation page explains where the line is.
- Call your insurer with realistic expectations. Sudden leaks are usually covered; a leak that obviously went on for months may be excluded as gradual. The sooner you find it, the better the claim looks. Georgia coverage, explained.
A once-a-season walk-through
Ten minutes, four times a year, catches most of this before it costs anything:
- Look up at every ceiling, especially under bathrooms and the attic HVAC.
- Open every sink cabinet and press the floor of it.
- Look behind the washer and under the refrigerator with a flashlight.
- Walk the basement or crawl-space perimeter and smell.
- Check the attic after a heavy rain and after a freeze.
- Read the meter with everything off.
- Replace rubber washing machine hoses every five years, braided steel every ten.
Frequently asked questions
How can I tell if water damage is old or new?
New water damage is wet to the touch and reads wet on a moisture meter; stains are soft-edged and the material has not yet deformed. Old damage shows dried rings with dark edges, swollen or delaminated material, cupping, and often mold. Many leaks are both — old damage with a leak still active behind it.
Can water damage be hidden behind a wall?
Yes, and it usually is. Water runs inside wall cavities and under flooring long before it shows on the surface. A moisture meter or thermal camera finds it without opening the wall; a small inspection hole behind the baseboard confirms it.
What does a slab leak look like?
A warm or damp spot on the floor, the sound of running water when nothing is on, a water bill that rose, the meter indicator turning with everything off, and sometimes cracks in tile or a musty smell. Common in metro Atlanta homes from the 1960s through 1980s with copper lines under the slab.
Is hidden water damage covered by insurance?
If it came from a sudden event you could not have known about — a pipe that failed inside a wall — often yes. If it is a leak that went on for weeks or months, insurers frequently deny it as gradual or as neglect. The faster it is found and documented, the better the claim.
Should I get a professional inspection if I only smell something?
If the smell is persistent and you cannot find the source in an afternoon, yes. A moisture survey of the suspect rooms takes an hour, and it is far cheaper than finding the problem when a wall is opened for another reason. It is also worth doing before closing on a house in a basement neighborhood.
Can Verus find where the water is coming from?
We can find where the water has gone — moisture meters and thermal imaging show which walls, floors and ceilings are wet, and how far. Locating a leak inside a pipe is a plumber’s job; we work alongside them. Call (404) 983-0966 or text HELP, 24 hours a day, across North Metro Atlanta.
Published by Verus Restoration, Norcross, GA — 24/7 water, fire, mold and storm damage restoration for 21 North Metro Atlanta communities. This article is general guidance, not a substitute for advice from your insurer, a licensed professional or emergency services. Call 911 for any immediate danger.