You can often tell if water is leaking behind a wall by watching when the signs appear, checking the other side of the wall, and testing nearby fixtures one at a time. Stains, soft drywall, and musty smells are the most common clues.
Look for the Usual Signs
A leak inside a wall often causes:
- Yellow or brown stains
- Bubbling, peeling, or cracking paint
- Drywall that feels soft or damp
- Baseboards that swell or pull away
A musty smell or small black spots near the floor can mean mold is starting.
Notice When It Happens
Timing can tell you a lot. If the wall gets wet only when someone showers, the leak may be in the shower drain, valve, or the seal around the tub. If it gets wet only when the washing machine drains, the drain line may be the cause. If the wall stays damp all the time, a supply pipe that is always under pressure is more likely.
Check the Other Side
Look at the room behind the wall, and the room below it if there is one. In many Staten Island homes, a basement ceiling under a bathroom or kitchen can show drips or stains that help pinpoint the leak.
Test Fixtures One at a Time
Turn off the water to nearby fixtures using their valves, one at a time. If the wet spot stops growing after one is shut off, that fixture or its piping is a good suspect. You can also check your water meter with all water off. If it keeps moving, a supply line is leaking.
Avoid cutting into the wall to look. You could damage pipes or wiring and make the repair bigger.
When you think water is leaking behind a wall, a plumber can find the exact spot so only a small area needs to be opened.
For help with a hidden leak, call JPR Plumbing at (833) 603-1840. After the repair, we can also offer help with the related fixtures and pipes if anything else looks worn.