Why Your Window is Leaking: Riverbedding, Weep Holes, and Caulking
Too Long; Didn't Read
- Diagnosis 1: Water inside the track? -> Blocked Weep Holes. Clean them.
- Diagnosis 2: Water on top of the trim? -> Caulking Failure outside.
- Diagnosis 3: Water under the window? -> Sill Failure or "Riverbedding".
- The Fix: Don't just silicone everything. You might trap the water inside.
Answer First: If you see water sitting in the track of your sliding window after a rainstorm, this is normal. It's designed to be there. It drains out slowly through the "Weep Holes" (little slots outside). If it overflows onto your floor, your weep holes are plugged with spiderwebs or dirt. Poke them with a wire coat hanger.
The Physics of a Leak
Windows are not submarines. They are designed to manage water, not repel it 100%. Gravity is the engine.
Common Cause #1: Blocked Weep Holes (80% of calls)
Vinyl windows are hollow. Water enters the screen track, flows into the frame, and exits outside.
- The Symptom: Water fills up the track like a bathtub and spills over the interior dam.
- The Fix: Go outside. Find the little black flaps or slots at the bottom of the frame. Clear the gunk. Flush with a bottle of water.
Common Cause #2: The Top Caulking ("Header")
- The Symptom: Water acts like a ghost. It appears on the top of your interior jamb or drips from the drywall above the window.
- The Reality: The leak might be from the roof, the brick mortar, or the siding above. Water travels behind the wall and hits the window header.
- The Fix: Check the caulking where the brick meets the top of the window. If it's cracked, replace it. BUT verify your flashing (drip cap) is actually shedding water away.
Common Cause #3: "Riverbedding" (The Installer Error)
When a window is installed, it needs a continuous bead of sealant underneath it (on the sill). If the installer left a gap, wind-driven rain pushes water underneath the frame.
- The Symptom: Drywall bubbling under the window sill.
- The Fix: This is bad. You might need to remove and reinstall the window. Adding more caulking outside usually just traps the water, rotting the wood framing.
When Condensation Looks Like a Leak
In winter, if you verify no rain but see a puddle:
- Interior Humidity: Your house is too humid (50%+). The cold glass condenses the moisture, it runs down, and pools.
- The Fix: Turn down your humidifier to 30%. Open the curtains to let air flow.
Summary Flowchart
- Is it raining?
- No -> Condensation. Turn down humidifier.
- Yes -> Go to 2.
- Where is the water?
- In the track? -> Clean Weep Holes.
- On the glass? -> Seal Failure (Foggy).
- On the drywall? -> Caulking or Roof issue.
Can't Stop the Water?
Water damage spreads fast. Book a "Leak Investigation." We use moisture meters and thermal cameras to trace the source.