Visible signs
- Water stains on walls or floor
- White mineral deposits on masonry
- Damp wall-floor joints
- Peeling or bubbling finishes
- Recurring puddles after rain
- Visible water through a crack
Odor and moisture
A persistent musty smell can indicate excess moisture, but odor alone does not identify the source. Condensation, humidity, seepage and plumbing can all contribute to damp conditions.
Track the pattern
Take photos and note the weather when symptoms appear. The pattern can make a later inspection more productive, especially if the basement is dry by the time someone arrives.