National Home Inspector Practice Exam

Water stains on ceilings or walls serve as a common and visible sign of a plumbing leak. When water escapes from pipes or fixtures, it can seep into surrounding materials, leading to discoloration and staining. This occurs because the water accumulates, often traveling from the point of the leak to areas where it can easily be observed, such as ceilings or walls beneath plumbing fixtures.

Identifying water stains is crucial for home inspectors, as it not only indicates a potential leak but also helps in determining the source and severity of the issue. Stains can also suggest prolonged exposure to moisture, which may lead to mold growth and structural damage if not addressed promptly.

While the other options can indicate plumbing issues, they are not as direct or specific signs of a leak. The odor of sewage often relates more to drainage problems, low water pressure can signal a variety of issues beyond just a leak, and increased water bills might suggest excessive usage but doesn't pinpoint the location or nature of a leak as clearly as visible stains.