The Effects & How to Prevent Window Seal Failure

Failed seals are one of the most common types of window problems that homeowners have. Even if you just bought your home you might have failed window seals. It’s difficult to tell when a seal fails so home inspectors aren’t required to inspect for them. Often times there may be no signs at all when a seal fails, but over time you’ll start to see the signs.

When a failed seal is left unfixed for a long time the consequences can eventually lead to a full window replacement. That’s expensive and can be a hassle. If you can catch the failed seal and have it fixed before it causes permanent damage you can save yourself time and money. Preventing it from failing completely is the best way to protect your home.

Since you may not be able to tell when a seal on your window fails you need to look for the effects of a failed seal. Spotting the effects of a failed seal and taking action immediately can prevent further damage and can lower the chances that water will get inside your walls and cause damage or cause mold growth inside the walls of your home. Below are the effects of a failed window seal.

window seal failure

Foggy Glass

One of the first effects of a failed seal that you will be able to see on your window is foggy glass. If you notice that one of your windows suddenly starts to look cloudy or foggy, even when the weather is bright and sunny, it’s probably because of a failed window seal. As soon as you notice the glass in your windows is fogging you should call a professional to come and examine the seal and fix it if necessary. If you recently had new windows installed, fixing the seal should be covered by the window’s warranty.


Another sure sign of a failed window seal is condensation on the window. If you notice water droplets or large water streaks on the windows, the seals on your windows have failed and will need to be fixed right away. The moisture that is on your windows can also get into the walls of your home and cause damage or even mold growth.


Just like water is a sure sign of the failure of a failed window seal, dirt or grime building up on the inside of the window is always a sign of seal failure. It can be very difficult to get the dirt and grime off of the window because it ends up etching the window or pitting the glass and making it necessary to replace the entire window.

How Window Seals Fail

The most common reason why window seals fail is that the seal is sitting in water and slowly deteriorates. If you have water draining inside the window frame it’s essential that the window seal is set up above the channel where the water drains so that the water doesn’t break down the seal and make it loose.

Once the seal has started to break down it will need to be fixed by a professional so it doesn’t get broken down by drainage water again. Channeling the water elsewhere will also help protect the window seal.

Another reason why window seals fail is exposure to heat. During the winter if you have your heat set on high that will have an effect on the window seals. If you live in an area that gets extremely hot during summers, the heat can also break down the seals on the windows in your home.

Unfortunately, there’s not much you can do to prevent the heat from taking a toll on your window seals except keeping an eye on them and having a professional check them at regular intervals to make sure they’re holding up.

windows sealed properly with sealant


Windows can last for decades, but eventually, those window seals are going to break down. If you’ve owned your home for a long time or if you recently bought an older home that still has the original windows, the seals on those windows might need to be replaced just because they’re old.

If you know that the windows in your home are old and you’re worried that the seals might be starting to fail, or if you have started to see some of the signs of failing window seals, call a professional to come out and assess the state of your windows. A professional window tech will be able to tell you if your window seals can be fixed or if they need to be replaced.

Preventing Window Seal Failure

If your window seals haven’t failed yet and you want to make sure that those window seals stay intact for as long as possible, there are some things that you can do to prevent window seal failures.

Check Them

The easiest way to prevent the failure of the window seals in your home is to check them regularly. Make it part of your seasonal home preparations to check the window seals and check the glass for any of the signs of failed seals like foggy glass, condensation, or small cracks or pits in the glass.

Write down your findings or take a picture of the windows and keep them in a file so that you’ll be able to look back and see if anything has changed the next time you check the windows. If you see any signs that the seals might be failing, call a pro to inspect them.

Improve Air Circulation

Since moisture can slowly cause the seals to break down one way to prevent the failure of the window seals is to make sure that there’s good air circulation in your home. Add some ceiling fans to the bedrooms which may not have great circulation or run some small fan throughout the house to keep the air moving.

In the winter time, better air circulation will keep hot air moving around the home instead of settling in one place and causing the seals on the windows to start breaking down. Adding plants to your home can also help clean the air and boost the air circulation so that there is fresh air moving around the home.

Keep Them Painted And In Good Repair

You should also keep your window frames and sills painted and in good shape to help protect the window seals. If the paint is peeling make sure that the window frames and sills are clean. Then scrape all the flaking paint and repaint the window sills and the window frame. You can use glue or wood filler to fix any nicks in the sills or the frames before you paint them.

If you’re not very handy around the house, hire someone to do the work for you. It’s worth the cost of getting those window sills and frames fixed. Preventing the window seals from breaking down will save you from having to pay to fix the window seals later on.

white painted windows installed

Get Quality Windows

Installing great quality windows the first time around will help prevent a failed window seal. If you’re looking to get your windows replaced, Feldco provides energy efficient windows that will last a lifetime.

With over 350,000 delighted customers, Feldco makes sure to offer the best products accompanied by the best professional installers. We offer many different styles and color options to complete your home. Talk to a product specialist and get your free quote today.

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