The short answer
Check the Seal and Caulk
Water entering at the top of a window often points to a failed seal. The caulk or sealant around the window frame can crack, shrink, or pull away from the siding over time. When that happens, rain can run behind the trim and drip down inside the wall, showing up as a leak at the top of the window.
Look closely at the joint between the window frame and the siding. If you see gaps, crumbling caulk, or discoloration, that is a likely entry point. You can reapply exterior-grade caulk yourself if the damage is minor, but if the wood underneath is soft or stained, the problem may go deeper.
- Inspect the caulk for cracks or gaps
- Check the trim for rot or soft spots
- Look for water stains on the wall below the window
- Feel the frame for dampness after rain
- Note the direction of wind-driven rain
Inspect the Flashing and Drip Edge
Flashing is a metal or plastic strip that directs water away from the top of the window. If the flashing is missing, bent, or installed incorrectly, water can pool and seep behind the window. The drip edge, a small lip at the top of the frame, also helps keep water from running back toward the glass.
Check the area above the window for any signs of flashing. If there is none, that could be the problem. If there is, see if it is loose or has gaps. A simple fix might involve resealing the flashing, but a replacement may be needed if it is badly damaged.
Look at the Roof and Gutters
Sometimes the leak is not from the window itself but from the roof or gutters above it. A clogged gutter can cause water to overflow and run down the exterior wall, finding its way behind the window trim. A damaged roof shingle or a leak in the roof valley can also direct water to the top of the window.
Inspect the roofline directly above the window. Look for missing shingles, rusted flashing, or debris in the gutter. If you cannot see the source from the ground, a ladder or binoculars may help. If the roof is steep or high, it is safer to have a roofer check it.
Consider Condensation and Air Leaks
Not every wet spot is a leak. Warm, humid air inside your home can condense on a cold window frame, especially in climates with hot, humid summers and frequent thunderstorms. Condensation can look like a leak, but it usually appears on the glass or frame rather than at the top joint.
Air leaks around the window can also allow humid indoor air to reach cold surfaces, causing moisture to form. Check the weatherstripping and the seal between the window and the wall. If you see water only in the morning or after cooking, condensation is more likely than rain intrusion.
When to Call a Pro
If you have checked the caulk, flashing, and roof and still cannot find the source, it may be time to bring in a local water damage pro. They can use moisture meters and other tools to trace where water is entering. A water damage inspection can also reveal hidden damage behind the wall.
If you live in an area with intense storms, a local water damage pro can help you identify issues that are easy to miss. Catching a leak early can prevent rot, mold, and structural damage. The cost depends on the extent of the problem and the type of repair needed.
- Water stains that grow after each rain
- Soft or spongy wood around the window
- Mold or mildew smell near the window
- Damp insulation inside the wall
- Leak continues after caulking
Talk to someone now
Water keeps spreading into floors and walls, so it is worth acting early. Calls are answered 24/7.
Call Now (469) 698-4610Frequently asked questions
Can I fix a leaking window myself?
You can reseal the caulk or replace weatherstripping if the damage is minor. But if the leak persists, the problem may be in the wall or roof. A local water damage pro can inspect and tell you what is needed.
Why does my window leak only during heavy rain?
Heavy rain can overwhelm the flashing or a small gap that only lets water in under pressure. Wind-driven rain can also push water sideways into joints that would otherwise stay dry. Check the caulk and flashing after a storm.
Will my insurance cover window leak repairs?
Policies vary, and your insurer decides what is covered. Some policies cover sudden water damage, while gradual wear and tear is often excluded. Check your policy and talk to your insurer about your specific situation.