Windows · Common problems · Updated November 2026
Water Leaking Around a Window Frame
Water stains on the sill, trim or wall under a window mean water is getting in somewhere. The window itself is not always the source; water can travel from the roof, gutters or wall above.
Possible causes
- Cracked or missing exterior caulk around the frame.
- Missing or poorly installed flashing above and around the window.
- Clogged weep holes in the bottom of the frame (on vinyl and aluminum windows).
- A failed seal between the glass and the sash.
- Overflowing gutters or roof issues sending water down the wall (why gutters overflow).
- Condensation running off the glass (mostly in winter).
What you can safely check
- Note when it leaks: only in wind-driven rain, any rain, or on cold mornings (condensation).
- Clear weep holes at the bottom outside of the frame with a soft wire.
- Look for gaps in caulk and peeling paint around the frame.
- From the ground, look for overflowing gutters above the window during rain.
- Press gently on the sill and trim: soft wood means rot.
When to call a pro
Call if you see soft wood, stains spreading on the wall, mold, or if the leak continues after re-caulking. Water inside walls can damage framing and insulation. A pro may recommend reflashing or a full-frame replacement.
Cost figures are national ranges from the sources listed in our windows cost guide, not a quote from FixFinch or any contractor. This article is general information to help you decide on next steps. It is not an inspection or professional advice; a qualified pro who sees the problem in person can tell you what is actually going on. Calls connect you with an independent service provider in our network. FixFinch is not a contractor and does not perform the work.