In some instances, something minor could have caused the stain – think a toilet overflowing on a floor above, or someone leaving the shower curtain open and too much water getting on the floor. These isolated instances seldom result in long-term damage.
In other cases, a ceiling stain could be a symptom of a much larger problem, and this is where your home inspector could help you find out before you finalize your purchase on a home.
Examples could be unfixed roof leaks, or even ice dams. Ice dams usually occur when there are clogs in your rain gutters, ice builds up during a winter storm, and then as it melts it has nowhere to go except inside your house. These are usually easily fixed by cleaning the gutters, but can also be a sign of a defect with the roof or gutters. A roof leak may have had an easy fix as well, yet the stain still show – or it could be a symptom of a larger and potentially recurring problem.
Homeowners will hopefully always repair ceiling stains at the same time the repairs to fix the underlying problem happen. Then when they are ready to sell, everything will be fixed. However, just because you see a stain on a ceiling, don’t assume a problem still exists. Your home inspector will do their best to find out if an issue is present, and provide the information in their report.