Short answer：Rain can reveal drainage, leakage and external conditions, but a visit without visible staining does not prove a defect-free property. Safety and professional inspection remain important.
Record conditions and locations
Within safe and permitted areas, inspect windows, ceilings, corners, bathrooms and common parts and note weather, smells and marks. Staining can have different causes; photographs alone do not establish responsibility or repair scope.
Check maintenance history
Ask about past leakage, façade and drainage work and arrange appropriate inspection where needed. Do not approach hazardous slopes, roofs or façades during severe weather merely to inspect a property.
Before deciding
- Also assess daylight and ventilation in dry conditions
- Keep seller and management responses
- Do not treat absence of staining as an inspection report
Sources and method
Sources support the specific rules described. Checklists and hypothetical calculations are editorial explanations, not measured market results or individual approvals.
Revision：Removed unsupported experience, case outcomes and statistics; corrected the topic-specific rules and limitations described above.
Scope：General information only, not personalised legal, tax, immigration, admissions or investment advice.