What is a key indicator of excessive moisture in a building?

Unusual humidity levels serve as a key indicator of excessive moisture in a building because humidity directly relates to the moisture present in the air. When humidity levels are higher than normal, it typically indicates that there is excessive moisture accumulation, which can lead to various conditions conducive to mold growth, structural damage, and other issues.

Monitoring indoor humidity provides insights into potential moisture problems. Ideally, indoor humidity levels should be kept between 30% and 50%. Levels above this range can lead to a stale environment where mold spores thrive, contributing to health hazards and exacerbate structural issues.

While cracked walls, high energy bills, and peeling paint may be symptoms of moisture issues, they don't provide as clear an indicator of moisture presence as unusual humidity levels do. Cracked walls could arise from settling or other structural problems, high energy bills might indicate issues with insulation or HVAC efficiency, and peeling paint is often a result of paint failure unrelated to moisture. Hence, unusual humidity levels are the most direct and clear signal of excessive moisture in the environment.