How Do You Fix Leaking Windows?

Are your windows leaking at the bottom corner? Do you have water pooling around the window frame or sill? Leaking windows can be a nuisance, causing water damage and mold growth if left unrepaired. Thankfully, fixing a leaking window is often a relatively simple and inexpensive task. With a few supplies, you can usually stop your windows from leaking when it rains. Follow these simple steps on how to repair leaking windows. Plus, we cover the main causes of window leaks and when it’s best to replace a leaky window.

Why Do My Windows Leak?

Not sure why your windows leak when it rains? The most common reason is worn-out caulk or seals. As your windows get older, the seals and caulk will dry out and crack. This can leave gaps between the window and the frame, allowing water to leak in on the window sill.

Windows leaking at the bottom corner of the frame or around the sill typically indicates cracked caulking or worn-out seals. You can easily fix the problem by replacing the caulk or seal. As long as you repair them quickly, you can prevent additional damage.

However, there are actually several potential causes of leaking windows. Here are the common causes of leaky windows:

• Worn-out caulk: Windows are sealed on both the outside and inside with caulk. Over time, the caulk will dry out, crack, and shrivel. The caulk should always form a smooth, clean seal. If water leaks around your window sill, the caulk is likely the problem. Another sign of damaged caulk is drafty windows.
• Damaged seals: Windows have rubber or silicone gaskets that seal the window and block out rain and moisture. The early signs of problems with your seals are moisture or condensation in between the glass panes. However, they can wear out over time, allowing water to leak in.
• Clogged drainage holes: Windows have small drainage holes that allow water that gets past the seals to drain out. If these holes are clogged, the water has nowhere to go and can leak into the home and pool around the window sill. Open your window and look for excessive dirt or gunk in the channel.
• Improper flashing: Flashing is a barrier that is installed around the window frame to prevent leaks. If the flashing is not installed correctly, it can cause a water leak. This can be hard to see but look for gaps or cracks around the sides of the window frame.
• Defective windows: In some cases, the window itself may be defective, which can cause it to leak. While window defects can cause leaks anytime, you will usually find the problem shortly after installation.
• Improper installation: Although rare, poorly installed windows can leak. This is usually caused by gaps in the caulk or sealants, but windows can leak if they aren’t seated in the frame correctly.
• Roof or siding leaks: Although technically not window leaks, water might seem like it’s coming through your windows if you have problems with your roof or siding. The water can come in through those holes, then drip or pool around the frame or window sill.

How Do You Find the Cause of a Leaky Window?

Finding the cause of a leaking window takes some detective work. You will need to inspect both the outside and inside of the window. If you cannot find an issue outside the window, you will also need to check your siding and roofing.

The following steps will help you find the cause of your window leaks:

1. Inspect the window from the outside: Look for any visible signs of damage, such as cracked or missing caulk or gaps around the frame.
2. Check for clogged drainage holes: These are small holes that are located at the bottom of the window frame. Use a needle or small wire to clear any debris that may be blocking the holes.
3. Look for faulty flashing: Flashing is a barrier that is installed around the window frame to prevent water from leaking in. If the flashing is not properly sealed or is damaged, it can allow water to leak through.
4. Inspect the window from the inside: Look for any visible signs of water damage, such as stains on the walls or ceiling, or peeling paint. If you do not find problems outside the window, you need to check your roof and siding as well.
5. Check your roof: Roof leaks can allow water to drip through walls and then pool around windows. Look at the outside of your roof for damaged shingles or gaps that let water in. Pinpointing roof leaks are sometimes easier from the attic.
6. Look at the siding: Lastly, check if the water is coming through your siding. Look for cracked or damaged siding panels around or above the leaky window.

If you still cannot find the leak, call a window installation company to inspect the issue. They have the training and experience to identify the cause of window leaks. Plus, they can make repairs to stop water from coming in when it rains.

How To Fix a Leaking Window

There are several methods you can use to fix leaking windows, depending on the cause of the leak. Here are some potential solutions:

1. Recaulk the Window

One of the easiest fixes is to recaulk the window. Starting on the outside of the window, use a utility knife or caulk removal tool to cut away the damaged caulk. Then reseal the window using exterior grade caulk. Repeat the process on the inside using regular silicon caulk.

2. Replace the Seals

You should replace damaged or cracked seals to stop window leaks. Typically, you can pry out the existing seals. However, the exact process will vary depending on the style and manufacturer of your windows. Contact your manufacturer or a window installer for replacement seals.

3. Repair or Replace the Flashing

If the flashing is the cause of the leak, you may be able to repair it using flashing repair tape. Repair tape can fix minor issues, but you will need to replace severely damaged flashing. However, this usually involves removing the siding around the window or even removing the window altogether. Consider hiring a window contractor for these repairs unless you are experienced in home improvement.

4. Replace the Window

If the window itself is defective or beyond repair, you may need to replace it. Although more costly and involved, replacing the window is the only option if the other methods do not fix the leak. While you can replace a leaky window yourself, it can be an involved process. You may need to hire a window replacement company to properly fix the leak. This is especially true if the leak causes the wood around the frame to rot or if there is structural damage.

5. Make Other Home Repairs

If the window is not the cause of the leak, you may need to make other repairs to your home. This usually includes roofing or siding repairs, but it will depend on the exact cause of the leak.