A persistent damp smell is worth investigating, but not every musty basement needs major excavation or a new drainage system.
Visible clues
Watch for repeated puddles, staining, efflorescence, and damp wall-floor joints.
Hidden clues
Warped baseboards, peeling finishes, and moisture-damaged storage may indicate periodic water intrusion.
Next step
Record when symptoms occur and request an assessment that separates condensation, plumbing, and groundwater issues.
What to do before hiring
Photograph the affected area and record when moisture first appears. Ask the person assessing the basement to distinguish water entry from condensation or plumbing, explain what the recommended work will accomplish, and identify the discharge route for any collected water.
If you see significant wall movement, widespread damage, or suspect an electrical hazard, arrange an appropriately qualified assessment before proceeding with routine waterproofing.