Wind washing reduces insulation performance at the eave

Outdoor air moves through or over low-density insulation, cooling the ceiling edge and altering attic moisture patterns.

Failure path

• Step 1: Wind enters near the eave.
• Step 2: Air passes through exposed insulation.
• Step 3: Effective thermal resistance falls.
• Step 4: Interior surfaces cool along the perimeter.
• Step 5: Condensation risk rises during cold humid periods.

What makes this pathway plausible

The timing, location and operating or weather trigger should repeat. A diagram shows a mechanism; evidence from the actual house determines whether it applies.

Best next observation

Record the trigger and compare the nearest materials, components and routes before opening finishes or choosing a repair.

Verification after repair

Recreate the original trigger when safe, then confirm the symptom does not return and affected materials are stable or drying.