Before repairing water at a window corner during wind-driven rain

Do not start with the cosmetic finish

Water at a window corner can enter through head flashing, cladding joints, sill drainage, frame seals or nearby wall defects. Surface caulk is only one layer.

Define the repair question

Ask which layer failed, what trigger activates it, how far the pathway may extend and what evidence will show that the source—not only the visible mark—was addressed.

Preserve a baseline

• Record wind direction and first wet point
• Photograph exterior joints from ground level
• Check whether sill drainage openings are blocked
• Keep one dated overview photo and one close view from the same position.
• Record the trigger state before work begins.

Scope questions worth asking

• Which competing cause was considered and what evidence weakened it?
• Which concealed layers may need access and which will remain untouched?
• How will wet or damaged material be assessed before closure?
• What comparable post-work condition will be used to verify the result?

Avoid the common shortcut

Do not caulk drainage openings or seal every cladding joint.

Escalation boundary

A window or envelope professional should inspect layered flashing and drainage.