How to Find a Hidden Water Leak in Your House in Mineola, NY.

Hidden leaks wear down homes quietly. They show up as a bill that climbs, a stain that appears, a smell that will not go away or a floor that feels warm. Most can be found with a few careful checks, and the earlier you look, the less there is to dry and rebuild.

Check the water meter

This is the simplest test. Turn off every faucet and appliance that uses water. Then look at your water meter. If the dial or digital flow indicator is still moving, water is going somewhere. If you can find your main shut-off, close it. If the meter stops moving, the leak is inside the house. If it keeps moving, the leak may be between the meter and the house.

Your water bill is also a clue. A sudden rise with no change in habits suggests a leak. Compare the last few months.

Use your senses

• Sound. Listen at night. A hiss or trickle in a wall can mean a pressurized line.
• Smell. A musty odor in one room points to hidden dampness.
• Touch. Cold, damp or soft spots on walls, ceilings or floors.
• Sight. Stains, peeling paint, bubbling wallpaper, warped baseboards or cupped flooring.
• Warmth. A warm patch on a slab floor can signal a hot water line leak, as covered under slab leak water damage.

Look at the usual suspects

1. Under kitchen and bathroom sinks, including supply lines and drains.
2. Behind toilets and around the base.
3. At the water heater, including the relief valve and connections.
4. Behind the washing machine and dishwasher.
5. Around tubs and showers, where caulk and grout fail.
6. In the attic and on ceilings, where roofs and vents leak.
7. In the basement or crawl space along pipes.

Toilets can leak silently. Put a few drops of food coloring in the tank. If color appears in the bowl without flushing, the flapper is leaking.

A ten minute leak walkthrough

Start at the water meter and note the reading. Walk through the house without using water for ten minutes, then read the meter again. A change suggests a leak. Next, check the toilets with food coloring, look under each sink with a flashlight and run a dry paper towel along supply lines. A towel that comes away damp points to a slow drip.

Finish in the basement or lowest level. Look along the ceiling for drips and along the floor for damp lines. Check the water heater's base. If you find nothing but the meter still moves, a hidden leak is likely and a professional can use detection tools to find it.

Do the same walkthrough again after heavy rain, since roof and foundation leaks only show then.

What to do once you suspect a leak: shut the main valve, avoid using electrical outlets near wet spots and call a plumber or a restoration company.

What professionals add

Moisture meters measure dampness in drywall, wood and concrete. Thermal cameras show temperature differences that can reveal wet areas. Acoustic tools can pick up the sound of a pressurized leak. A plumber can pressure test lines. Together, these tools can find a leak without tearing out walls.

Restoration companies use them to map the wet area before drying. Plumbers use them to find and fix the source. Often you need both, and the order is plumber first or restoration first depending on how bad the water is.

After you find it

Once the source is fixed, drying matters as much as repair. A fixed pipe in a wet wall can still lead to mold. See structural drying for how dry-outs work.

Preventing the next one

Replace old supply hoses with braided lines. Know where your shut-offs are. Check under sinks twice a year. Consider a leak sensor near the water heater, washing machine and sinks. Test them with the batteries each fall.

Homes in New Hyde Park and Albertson often have older lines that run through finished basements, so check those areas first.

Questions about this topic in Mineola