The stain is a clue, not a diagnosis
Water can travel along slabs, joints and finishes before it becomes visible. Rain timing, water use and previous repairs help an investigator narrow the source; they do not establish it by themselves.
Leak investigation assistant
Turn what you can see into a useful brief for an inspection.
Your worksheet
Before you decide
Collect evidence safely
Photograph the affected area from a safe position, record dates and weather, and note changes without opening ceilings, flood-testing a room or accessing a roof. For a condominium, coordinate access with the managing agent where shared areas or another unit may be involved.
What happens after an initial visit?
The first assessment may identify a need for controlled testing or further access. Agree that scope before work starts. A repair proposal should explain the suspected cause, supporting observations, method, exclusions and how completion will be checked.