Damp will need ventilation , possibly checking for heat exchange issues such as warm air meeting cold surfaces. Insulation may be needed as well as ventilation.
If we have leak? Or water penetration? We need to pinpoint source and remedy.
Pipes? Ground water? A membrane may be needed. Then waterproof paint or sealer.
If it's a major job we may be better off getting an expert in . Though possibly not cheap, we ought to get a decent fix and possibly either a warranty or free aftercare.
not have a window down there. A lot of dirt and water can get through them. Also make sure there aren't any cracks or leaks in pipes that need to be sealed
