Window Water Damage: Signs, Causes & Fixes

Is water leaking around your window? If so, you must act fast to prevent costly damage!

Fortunately, you’re not alone.

Here at ServiceMaster of Lake Shore, we’ve been helping Chicago-area customers prevent and repair water damage for years. We’ve compiled our top tips into this comprehensive blog.

Before You Get Started

• Prioritize safety. Before you start repairing window water damage, take steps to make the area as safe as possible. Start by shutting off power in areas affected by water and donning protective gear like gloves, safety goggles, and a mask to protect yourself from any debris in the space.

• Gather your tools and supplies. Make sure you have everything you need to tackle the issue. We recommend collecting a wet/dry vacuum, a few fans, a dehumidifier (rent a commercial-grade dehumidifier for maximum efficacy), a caulk gun, waterproof tape, some cleaning solutions designed to kill mold, and any needed replacement seals for the window itself.

• Decide if this is a DIY job. Window water damage can be tricky to repair, and it’s worth taking a moment to consider whether you want to tackle this on your own. If the damage is minor, you may be able to handle the needed repairs by yourself. If the damage is extensive, though, or there are structural concerns or mold growth present, we recommend contacting a certified water damage restoration company for professional assistance. 

Causes, Signs, and How to Fix Window Water Damage

1. Cause: Poor Window Insulation

Signs: 

• If you’ve got a window insulation issue, you may notice water stains or damp spots around your window frame.
• The window may feel drafty or cold.
• There may be visible gaps in the spacing between the window and the frame.
• It may be tough to open and close the window properly. 

How to Fix it: 

• Dry the area: Open windows (if the weather is warm and dry), use fans, and add dehumidifiers to water-damaged areas to reduce moisture.
• Remove damaged material: Check the areas around the window – like the wall and floor – for signs of water damage, like discoloration and soft spots. Remove damaged drywall, baseboards, or trim.
• Clean the area: Use a mold-killing solution to clean the affected area. You can also make a mixture of 1 cup of bleach in 1 gallon of water. 
• Seal the window gaps: Grab your caulk gun and use a high-quality waterproof caulk to fill the gaps around the frame. 
• Add weatherstripping: Add weatherstripping to drafty or leaky windows to improve insulation and minimize water intrusion. 
• Cover the window: If there’s wet weather in the forecast, use a heavy-duty tarp to cover the window and keep water from getting in.

2. Old or Damaged Window Frames

Signs:

• Cracks, warping, or decay on or around the window frame.
• Mold growth, water stains, or discoloration around the window frame.
• Windows that are difficult to open or close since the frames are warped.
• Window frames with peeling, blistering, or bubbling paint.

How to Fix it:

• Get rid of loose material: First, remove loose or rotten wood, damaged frame parts, or peeling weatherstripping.
• Cover the window: If a permanent repair will take a while, use heavy-duty plastic sheeting or a tarp to cover the window and prevent water entry.
• Dry the area: Once you’ve removed damaged material, use a fan or dehumidifier to dry the area and reduce moisture. 
• Replace damaged materials: Replace damaged parts of the window frame (or hire a professional to do it for you). If you could salvage most of the window frame, sand down any remaining wood areas and treat them with a wood preservative. 
• Use a wood filler or sealant: Next, use a wood filler to fix minor damage on wooden frames. Use a store-bought sealant to repair minor damage if the frame is vinyl or aluminum.
• Repaint and refinish the area: Finally, apply a primer and a coat of paint to the wood to protect it from future water damage. 

3. Defective Seals or Faulty Weatherstripping

Signs:

• Condensation that builds up between window panes.
• Windows that are drafty near their edges.
• Weatherstripping that is peeling or cracked.

How to Fix it:

• Dry the area: Use towels to soak up excess moisture, and then bring in fans and dehumidifiers to dry the area out.
• Remove damaged weatherstripping: Remove broken, worn-out, or damaged weatherstripping and replace it with new weatherstripping around the affected window. 
• Apply a sealant: Use a silicone-based sealant to fill gaps or cracks around window seals or the new weatherstripping. 
• Check exterior caulking: Go outside and look at the window from that perspective. Scrape away old caulk and replace it with waterproof caulk. 

4. Clogged or Faulty Drains

Signs:

• Water that pools around window sills
• Damp or water-stained window sills
• Visibly blocked gutters and window drainage channels

How to Fix it:

• Get rid of blockages: Remove visible debris from gutters, downspouts, and window drainage channels. This will remove standing water and allow moisture to stop pooling. If you can’t remove the blockage, use a tarp to redirect water away from the window.
• Dry the area: Use fans and dehumidifiers to dry out damp spots and reduce moisture.
• Check for additional damage: Inspect nearby walls, floors, and windowsills to identify other areas of water damage.
• Clean the area: Use a mold-killing cleaner and allow it to dry thoroughly.
• Fix and replace damaged parts: Repair damaged components of window sills, drywall, or baseboards. If the damage was extensive, consider hiring a professional to make these repairs for you. 

5. Cracked or Broken Window Panes

Signs:

• Window panes that are visibly cracked or chipped. 
• Moisture, water droplets, or condensation between panes.
• Drafty windows.

How to Fix it:

• Dry the area: Use towels, mops, fans, and dehumidifiers to dry the affected area and prepare it for repair. 
• Install temporary window films: Use a temporary window film to prevent drafts, hold cracked glass together, and prevent further damage.
• Replace the damaged window pane: Next, remove or replace broken or cracked window panes to restore the window and prevent any future leaks. 

6. Defective Roof Flashing

Signs:

• Damp spots and water stains around windows, especially on the house’s upper floors.
• Leaks that appear after heavy rainfall or severe storms.
• Gaps and damage to the flashing around your roof edges, chimney, or the spaces where the roof meets the wall.

How to Fix it:

• Cover the area: Use a tarp to cover the roof near the window, which will prevent future water intrusion. 
• Dry the area: Use fans and dehumidifiers to dry the area once you’ve stopped the water from leaking in. 
• Remove damaged materials: Next, remove any drywall, insulation, or ceiling materials damaged by water. As you do, treat the affected areas with mold-killing cleaner.
• Seal the area with roofing cement: Use roofing cement or sealant to fill gaps and cracks around the flashing. 

7. Cause: Condensation Build-Up

Signs:

• Water droplets or condensation on the glass.
• Accumulated water on the window sill.
• Mold or mildew developing around the window frame or on the surface.

How to Fix it: 

• Ventilate the room: Open windows or turn on exhaust fans to boost airflow and lower humidity. Consider using a dehumidifier to remove extra moisture from the air.
• Wipe down windows: Regularly clean windows to remove condensation and prevent water damage.
• Dry affected areas: Use fans, towels, or a dehumidifier to dry any water that has collected on sills or around the window frame.
• Check for mold growth: Check for mold and mildew (follow the tips in this blog to learn how) and clean it with bleach or a store-bought mold remover.

8. Cause: Improperly Installed or Damaged Window Well

Signs:

• Water buildup in basement window wells. 
• Stains or leaks around basement windows. 
• Mud, debris, or water seeping through the window well.

How to Fix it:

• Clear debris: Remove any debris or blockages from the window well to ensure proper drainage. 
• Install a cover: Use a clear plastic cover to protect the window well from rain and debris temporarily. 
• Divert water: Direct water away from the foundation by creating barriers or regrading the area around the window well. 
• Eliminate moisture: Use a wet/dry vacuum to remove standing water from the window well or basement. Fans or dehumidifiers can help dry damp areas around the basement window. 
• Treat mold: Clean water-damaged areas with mold-killing solutions. 
• Inspect and replace: Remove and replace any damaged drywall, flooring, or insulation as needed.

9. Cause: Inadequate Overhangs or Eaves

Signs:

• Water stains or leaks on walls near windows, especially after heavy rain.
• Water dripping or splashing near windows that are close to your roof edge.

How to Fix it:

• Add temporary drip edges: Install temporary drip edges or gutter extensions to guide water away from windows. 
• Seal any gaps: Use a temporary sealant to close off any openings where water might be coming in. 
• Dry and clean affected areas: Use fans, dehumidifiers, or towels to dry wet spots or water stains. 
• Check and fix damaged surfaces: Examine drywall, trim, or paint for damage and repair or replace them as necessary.

10. Cause: Cracked or Missing Roof Shingles

Signs:

• Watermarks or leaks near windows on higher levels. 
• Visible damage to the roof, such as missing or broken shingles. 
• Water dripping or indications of leaks during or after rainfall.

How to Fix it:

• Dry wet areas: Use fans or dehumidifiers to dry any spots that got wet from leaks.
• Cover with a tarp: Temporarily cover areas of the roof with missing or damaged shingles using a tarp.
• Apply temporary sealant: Fix small cracks or holes with roof cement or sealant.
• Check for additional damage: Inspect for hidden damage around windows, in the attic, or on walls, and remove any water-damaged materials.
• Repair damaged surfaces: Replace any damaged drywall, insulation, or window trim.
• Clean to prevent mold: Use a mold killer on affected areas to prevent the spores from spreading. 

11. Cause: Structural Shifts or Settling

Signs:

• Cracks in walls or near window edges. 
• Windows that are hard to open or close smoothly. 
• Spaces between the window and its frame.

How to Fix it:

• Temporarily seal openings: Utilize caulk or sealant to close gaps or cracks near windows.
• Reinforce framework: Install temporary supports to stabilize any windows that are shifting.
• Replace damaged materials: Remove any drywall, trim, or structural components that exhibit water damage.
• Eliminate moisture: Use fans or dehumidifiers to dry out moisture around the windows.
• Prevent mold growth: Clean water-exposed areas with mold-killing products. Mold can develop in as little as 24-48 hours after water damage, so it’s essential to do this quickly.

Water Damage Around Your Window Sills? ServiceMaster of Lake Shore is Here to Help!

Don’t let water damage take over your home or create dangerous mold and mildew in your space.

Contact ServiceMaster of Lake Shore for professional, reliable water damage restoration services.

Call our team at (312) 707-8597 to learn more about our services and how we can help you.