Window & Door Leak Repair

Windows and doors are the most common entry points for wind-driven rain. Even well-installed windows can leak when flashing fails, sealant deteriorates, or drainage channels become clogged. Our window and door leak repair service identifies the exact entry point and seals it — without the cost of full window replacement.

A window or door that leaks during a storm is not necessarily a bad window. The leak is usually a failure of the installation — the flashing, sealant, or weatherstripping that integrates the window into the wall assembly. The window itself is often fine. That is good news because it means the leak can be repaired without replacing the window, and the repair is usually faster and cheaper than the homeowner expects.

Why Windows and Doors Leak

Failure Point	What Happens
Flashing failure	The metal or membrane flashing around the frame has deteriorated, allowing water to enter behind the siding
Sealant deterioration	Caulk and sealant around the frame has cracked, shrunk, or separated
Drainage blockage	The weep holes or drainage channels at the bottom of the frame are clogged with debris
Improper installation	The window was not integrated correctly with the weather-resistive barrier (WRB)
Frame damage	The window frame itself has warped, cracked, or corroded
Weatherstrip failure	Worn or compressed weatherstripping allows water to enter at the sash

Signs of a Window or Door Leak

• Water stains on the wall below the window — the most common visible sign
• Damp drywall or peeling paint — moisture behind the wall surface around the frame
• Musty odor near the window — a damp smell means moisture is trapped in the wall cavity
• Visible gaps or cracks — gaps between the frame and the wall, or cracks in the sealant
• Condensation between window panes — a failed seal on double-pane windows
• Drafty windows — air leaks often accompany water leaks

Our Window and Door Leak Repair Process

Step 1 — Water Testing

We systematically flood areas around the window or door with a controlled water source while someone inside monitors for water entry. This isolates the exact failure point — top, sides, sill, or frame.

Step 2 — Visual Inspection

We inspect the flashing, sealant, drainage channels, and frame for visible damage or deterioration. We check the weather-resistive barrier (WRB) behind the siding for damage.

Step 3 — Repair the Leak

Depending on the failure:

• Flashing repair — replace or extend flashing to properly integrate with the WRB
• Sealant replacement — remove old caulk and apply new sealant compatible with the materials
• Drainage clearing — clear weep holes and drainage channels to allow water to exit
• Weatherstrip replacement — install new weatherstripping to seal the sash
• Frame repair — patch or replace damaged frame sections
• Sill pan installation — install a sill pan to direct water out of the wall assembly

Step 4 — Verify the Repair

We re-test with water to confirm the leak is sealed. Multiple tests may be needed if the entry point is complex.

Step 5 — Interior Repair

Water-damaged drywall, insulation, and trim around the window are repaired and restored.

Window Leak Repair Cost Guide

Service Item	Typical Cost Range	What’s Included
Water testing and inspection	$150 – $300	Controlled flooding, interior monitoring, leak location
Sealant replacement	$150 – $400	Remove old caulk, clean, new sealant application
Weatherstrip replacement	$100 – $300	New weatherstripping, sash seal
Flashing repair	$400 – $1,200	Flashing replacement or extension, integration with WRB
Sill pan installation	$300 – $800	Sill pan, drainage integration
Interior drywall repair	$300 – $800	Cut out wet drywall, insulate, tape, mud, paint

Expert tip: The most common window leak is not at the top — it is at the bottom, where the sill meets the wall. Water that hits the glass runs down the window and pools at the sill. If the sill pan is missing or the drainage channels are blocked, that water has nowhere to go but into the wall. Checking the weep holes and the sill pan should be the first step in any window leak investigation.

DIY Window Leak Repair vs. Professional Service

Applying caulk to a gap around a window frame is a common DIY fix, but it often does not solve the leak:

• Caulk alone does not fix flashing — if the leak is caused by failed flashing behind the siding, caulking the visible gap does not stop the water.
• Wrong caulk type — silicone, acrylic, and butyl caulks have different adhesion and expansion properties. Using the wrong one for the material causes the seal to fail again.
• Hidden drainage paths — sealing a visible gap can actually block the weep holes that are meant to drain water, making the leak worse.
• No verification — without water testing, you cannot be sure the leak is actually sealed.

Professional leak repair uses the right materials, addresses the true failure point, and verifies the repair with water testing so it does not return.

Preventing Window and Door Leaks

• Inspect sealant annually — check the caulk around every window and door frame and replace any that is cracked, shrunk, or separated
• Clear weep holes — keep the drainage channels at the bottom of window frames free of debris, paint, and dirt
• Check weatherstripping — replace worn or compressed weatherstripping before the storm season
• Maintain flashing — inspect flashing around windows and doors, especially after storms, and repair any damage promptly
• Ensure proper grading — water that splashes up from the ground against the window sill can enter through the frame
• Trim vegetation — branches and leaves that touch window frames trap moisture and accelerate sealant failure

Window and Door Leak Repair by State

Window and door leak patterns follow the weather of each region. In coastal and Gulf states, wind-driven rain from hurricanes and tropical storms tests window and door seals at their worst. In the Northeast and Midwest, freeze-thaw cycles cause sealant and flashing to fail as the materials expand and contract with each season. In the Southeast, high humidity and heavy rain accelerate sealant deterioration. In the Southwest, monsoon storms with intense, wind-driven rain expose window and door leaks. Our local crews know the weather patterns and building practices in their region and repair the leak for the conditions that matter. Check our locations page for the states and cities we currently serve, and call for window and door leak repair near you.

Related Services

• Roof Leak Repair — find and fix roof leaks
• Water Damage Inspection — thermal imaging and moisture mapping
• Water Damage Restoration — complete extraction, drying, and restoration
• Drywall Restoration — replacement of water-damaged drywall
• Storm Damage Restoration — full-service storm damage response
• Moisture Mapping — thermal imaging to find the extent of moisture around windows

Fix Your Window Leak

Call our team for professional window and door leak repair. We find the entry point, seal it properly, and restore any interior water damage — documented for your insurance claim and backed by a written warranty.