A brown ceiling stain that appeared only after wind-driven rain
The stain was far from the roof defect because water travelled along the underside of the roof deck before dropping at a ceiling joint.
✓Contractor Confirmedrecorded confirmation level
01 / OBSERVED
→Localized brown ceiling stain
02 / CONFIRMED CAUSE
→Failed flashing at a roof penetration
03 / REPAIR
→Flashing was rebuilt and the wet insulation was replaced after drying verification.
04 / VERIFY
No moisture increase during three later storms from the same wind direction.
WHAT CHANGED THE DIRECTION
The evidence that separated the cause
Supporting clues
- Only after southerly wind
- No change after bathroom use
- Moisture path visible in attic
Checks performed
- Weather correlation
- Attic inspection during rain
- Moisture map
Field lessonThe visible stain is often the endpoint, not the point of entry.
