Knowledge · Leak & waterproofing encyclopaedia

Window and Windowsill Seepage After Wind and Rain

Windowsill leaks are common—check sealant and drainage before DIY resealing or external frame repair.

Common causes

Cracked or missing silicone.
Loose screws and corners.
Failed stone sill joints.
External cracks or ponding on AC ledges.

After a storm

Dry the area and watch which joint wets first.
Check indoor sealant for mould or hollowness.
Inspect frame drainage holes for blockage.
Photograph for management or contractors.

DIY vs pro

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