5 Early Signs of Leaking Windows You Need to Address

Drip. Drip. Drip. There’s nothing more frightening and frustrating than hearing a dripping noise and suspecting a leaky window.

When a window fails, what do you do? You grab a towel, put a container under the window, and wait for the rain to stop. Perhaps you Google a DIY solution like adding sealant or caulk around the broken seal in a futile attempt to fix the problem.

A macro-closeup image of the corner of a window covered in beads of water condensation dripping down the glass onto the wooden window frame.

How Do You Know If the Window Is the Problem?

Unfortunately, “quick fix hacks” don’t usually work with leaking windows. At best, they temporarily alleviate the problem, and at worst, they trap the water inside the walls, making the situation worse. If you don’t address the source of the leak, you’ll still face damage—even if a “band-aid” might seem helpful at the time.

What happens down the road is that water trapped around your windowpanes rots your walls, causing mold growth, mildew, and extensive damage. If you have a water leak, it’s crucial to figure out the root of the problem and work on a better, long-term solution.

Do water leaks always mean you need new windows? Not always, but it’s often the answer. Window replacement is the best way to ensure your energy bills go down and your window panes (and the rest of your home) don’t show further signs of damage.

Sometimes, there could be a crack in the window sill or another minor issue causing the problem. However, the first step is to have a professional assess the situation. The last thing you want to overlook is structural damage in your house.

Even new windows can show moisture damage (and lack of energy efficiency). Many new building materials aren’t the highest quality. Poor installation can sometimes lead to costly repairs and a significant problem. We’d love to say that we never see signs of water damage in brand-new homes, but it’s becoming a more common problem.

If you suspect you have a severe issue or see signs of leaks, it’s important that you contact a window installation professional before water accumulation leads to further damage. New caulk won’t make up for low-quality windows; you need a professional installation.

But sometimes, the signs of leaking windows aren’t as apparent as a steady drip. A visual inspection of your windows might only show a little water infiltration. It won’t tell you the cause of the leak or how it may impact the substructures of your home.

5 Signs of Leaky Windows to Address ASAP

Here’s what you need to know about the early signs of leaking windows (so you can get ahead of the issue).

1. Rotten Wood on the Exterior

One of the telltale early signs of a leaking or potentially leaking window is wood rot around the window’s exterior. Wood rot can appear as cracking, peeling paint around the windowsill. It’s also indicated by off-kilter joints when the pieces of the windowsill don’t correctly meet or seem slightly misshapen. Soft spots are a sure sign that wood windows are starting to fail.

At first, this problem seems like no big deal. Your windows may still function correctly, even if you notice outside damage. In time, however, wood rot will lead to seal failure and more significant problems. Wood rot is a sign water is running toward your home instead of away; this could be due to gutter issues, roof issues, or another problem.

Homeowners should learn the signs of wood rot and address them ASAP. Often, a leaking window signifies the problem has escalated out of hand. The window will typically need replacement, and there may also be additional concerns. Don’t wait for the window to drip. Call Weather Tight today!

2. Cloudy Windows

Another sign of window seal failure is cloudiness between glass panes. Newer thermal windows don’t have big spaces between the panes of glass like older (non-thermal) storm windows do. Thermal windows contain insulating noble Argon gas to keep temperatures steady. The space between the panes should never be cloudy or wet in newer and even older windows.

Should the seal around the window fail, moisture accumulates between the panes of glass. To the homeowner, this usually looks like cloudiness or dirtiness that you can’t get clean. You may also see moisture built up between the panes of glass (this is different from condensation, which is a normal phenomenon and a sign your window is working correctly).

While your window might not be leaking (yet), cloudiness is one of the most common signs that its seal has failed. Eventually, the window will start to leak, which could damage the wall, floor, and surrounding areas of your home. At the first sign of cloudiness, take immediate action and give Weather Tight a call!

To see an example of seal failure and this type of cloudiness, please see the video below from Tod & Todd’s Home Improvement Tips:



3. Drafty Closed Windows

Window drafts are another big sign you should consider replacement windows. While we may not think of air as a conventional sign of a leaking window, the truth is air leaks make your home just as uncomfortable as water.

Look at your window when it’s closed on a very windy day. Does the curtain, blind, or shade move with the breeze? A simple damp hand test will also help you detect window leaks. Wet your hand and run it slowly around the window—do you feel cold air? That’s a big sign of your window leaking air.

If you get out the double-sided tape and shrink-wrap every autumn to “seal” your windows, you already know the inconvenience and frustration of having drafty windows. Plastic on the windows isn’t something you just need to accept because you live in a colder climate like Southeastern Wisconsin. With proper replacement windows, you’ll no longer get drafts; you can put the plastic away and enjoy the comfort of your home. Better yet, you’ll also see savings on your energy bill!

4. Black Fuzz and Dampness

As mentioned above, condensation isn’t a sign of a window leak (or an indication that your window isn’t working correctly). In fact, condensation is a positive sign that your window is airtight. When a window’s seal is broken, you won’t see condensation. Dry air will dissipate the moisture before it shows up on the window.

It’s essential to understand the difference between condensation and window leaks. The dampness from a window leak will often show up in one specific spot or as a puddle near the window. You may see black fuzz, mildew growth, or mold building up in an area on the window frame inside or outside your home. You may also see moisture between the panes of glass, cracking and bubbling paint, or warping of the window components.

Anytime you see black and soft or spongey wood around your window, address it immediately.

See the video below from Tod & Todd’s Home Improvement Tips for an example of a window with this type of seal failure:


5. Dripping (The Most Obvious Sign of a Leak)

Obviously, if there’s water dripping INSIDE your home during a rainstorm, it’s a clear sign your window is leaking. If it’s sudden, make one small check before you worry—ensure you’ve fully engaged the lock on your window for an extra tight seal. This is a commonly seen concern when homeowners forget to lock their windows, adding an extra snug closure.

If your window is still leaking, it’s time to call a professional. Unfortunately, window leaks can cause significant damage to your home and your belongings. It’s crucial you don’t wait to address the problem. Get it taken care of right away.

Fortunately, many options are available for beautiful replacement windows that will perform and protect your home for years to come. A Weather Tight professional will be happy to assess your home’s windows and help you find the perfect solution.

Contact us today for a free, no-obligation estimate. Leaking windows aren’t a problem you need to live with! Keep your home comfortable and worry-free with beautiful replacement windows you can rely on.