Pipes
Six Signs of a Hidden Water Leak
Leaks inside walls and floors announce themselves indirectly. These are the signals to watch for.
What a concealed leak looks like
By the time water appears on a ceiling, it has usually been leaking for a while. Concealed leaks announce themselves in less obvious ways first, and noticing early is the difference between a repair and a renovation.
- A water bill that rises with no change in household use
- A musty smell concentrated in one room, closet, or cabinet
- Paint bubbling, wallpaper lifting, or baseboards swelling
- A persistently warm or damp spot on a floor, which can indicate a hot water slab leak
- The sound of running water when every fixture is off
- Discoloration or a ring-shaped stain on a ceiling or wall
A test anyone can do
Turn off every water-using fixture and appliance in the house, including ice makers. Then look at your water meter. Many meters have a small low-flow indicator that spins with even a tiny flow. If it moves with everything off, water is going somewhere. Note the reading, wait an hour without using water, and read it again.
What to do next
Don't open walls looking for it. Concealed cavities also carry wiring and sometimes gas piping, and guessing wrong means repairing drywall for nothing. Plumbers locate concealed leaks with acoustic and thermal equipment. Take dated photos of anything you've noticed and hand the plumber the meter reading — you'll have saved them, and yourself, diagnostic time.
General educational information. Plumbing codes and licensing requirements vary by state and locality.