Water leaks around the house are often 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 too 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. Here are a few places to look for stains: around windows and doors, ceilings and the bottom of cabinets under sinks. If you notice any stains, have them checked out immediately by a professional plumber. A leak will not fix itself and left alone can lead to extensive and expensive damage!