Water leaks around the house often get underestimated in their potential to cause serious damage. A trap that's not tight, a toilet seal that's lost its grip, or even a water line with a tiny drip may be hard to see or hear, but every day it continues to wear away parts of your home, causing mold growth and leaving behind any number of problems for you and your home. A stain is one of the few visual clues that can provide a warning.

Where to look for stains:

  • Check around windows or the bottom of exterior doors. This can be an indication that water is entering from the outside.
  • Check at the joint between the ceiling and an exterior wall. This could be an indication of a roof leak or a sign that you have an ice-damming problem.
  • Check anywhere else along the ceiling. Unless you have water lines that run in the attic, which is pretty uncommon, a ceiling stain almost certainly indicates a roof leak. Remember, that the location of the stain does not necessarily mean the roof leak is right above it – it usually originates higher up and drips down.
  • Check in cabinets. If you see a water stain or a whitish ring on the floor of a cabinet that houses a sink, it's probably a sign of water leaking from the trap, or from somewhere else in the sink's drain system.
  • Look for mold and mildew stains. If you see mold or mildew growing, it's an obvious indicator of a moisture problem, but not necessarily an actual water leak. In a bathroom, it usually means there's inadequate ventilation to rid the room of moisture. At the bottom of an exterior wall, it might mean ground water from sprinklers or other sources is coming in. In a closet, behind a bed, or in other areas with little or no air circulation it could mean a variety of things, most likely an overly damp crawl space.

If you suspect you have a leak, call a plumber immediately! A leak will not fix itself and left alone can lead to extensive and expensive damage!