How to Prevent Mold On Windows? 7 Ways To Prevent Mold

Photo of a window full of mold. How to Prevent Mold On Windows?

Window mold is no one’s idea of a good time, but it is a very common problem. Learning how to prevent mold on windows will help you get to the bottom of the issue. Read on for more details!

If you have a recurring problem with mold around your windows, you can help minimize it by checking for any leaks around your windows, keeping the area dry by promoting airflow, keeping your home warmer, and cleaning your windows and frames regularly.

Below, I’ll discuss how to prevent mold around your windows. These range from short-term to long-term fixes to help keep your home safe and healthy!

7 ways to prevent mold on windows

If you want to keep your windows mold-free, these 7 fixes will help you do just that. These work preventatively if you don’t have a mold problem and are just planning, or they work after you’ve cleaned up a mold problem and want to prevent it from happening again. 

  1. Clean your windows regularly
  2. Keep your frames dry
  3. Check for any leaks around the window frame
  4. Use a dehumidifier
  5. Open the windows to allow fresh air to circulate
  6. Turn up the heat
  7. Consider an air exchanger

1. Clean your windows regularly

You should always add “clean windows” to your chores list. Many don’t because windows and their sills don’t seemingly get dirty. Yet dust and dirt can build up in those crevices and corners. It creates the perfect environment for water to mingle with and create mold. Clean your windows and sills as often as you do the rest of the room to prevent mold.

2. Keep your sills dry

I mentioned cleaning your windows and frames, but it’s also essential to keep your window sills dry. Clean up condensation and spills from water glasses, potted plants, etc. These “little spills” won’t just evaporate. They’ll create an ample situation for mold! Give your frames and sills a wipe-down with a dry cloth at the same time.

3. Check for any leaks around the window frame

One of the biggest causes of mold growth is a leak around the window frame. You’ll need to install an airtight sealant around the window frame to separate cold air and warm air. It also ensures that no moisture makes its way into your home, creating a breeding ground for mold.

4. Use a dehumidifier

If you live in a humid climate or have a high humidity level in your home, you’ll want to install a dehumidifier in your problem areas. According to PEHSU, mold is most common in bathrooms. It’s the most humid room in the house, so you’ll want to add a dehumidifier fan and run it if condensation builds up.

5. Open the windows to allow fresh air to circulate

Another option to help prevent mold around windows is to keep airflow moving. Run fans throughout your home, open windows to create a cross-breeze, and so on. Drawing fresh air in and then circulating it throughout your home will be an ideal way to help keep moisture and humidity to a minimum.


Don’t forget to always use the bathroom and kitchen exhaust fan to draw out unnecessary moisture when showering and cooking. They are installed and recommended for a reason!

6. Turn up the heat

If your room is too cool, the air hitting your window pane condenses and creates moisture. If you turn up the heat a few degrees, it’ll help stop moisture build-up. If you want to keep energy costs low, you can turn up the heat in those moisture-rich rooms (like your bathroom or kitchen) and turn up the heat there. 

7. Consider an air exchanger

These are ventilation units that run throughout your home to each room. They work by drawing fresh air into your rooms and simultaneously sucking stale air out. Consider one of these retrofits for your home if you have an older home and/or live in a humid climate. Since many living in hot or humid climates don’t want to open their windows often, this can achieve the same effect without any kind of exertion or effort.

Should you leave windows open to prevent mold?

You already know that getting fresh air circulating will be a good thing. Leaving the windows open will help prevent mold by keeping the drips from collecting in those problem areas. Just ensure that you don’t introduce new moisture to your room by leaving the windows open during a stormy day! Any time the weather gets more humid outside than inside, you’ll want to close the windows.

Does opening blinds prevent mold?

Opening the blinds or curtains in your room will help prevent mold. UV rays can pour in and help break down mold at a DNA level. We often hear about sunshine being the cure for many things, which will be the case with mold! If you allow sunlight into your room regularly, it’ll break down mold (especially with it’s at its spore stage) and helps further any kind of work you’re doing with air circulation.

Will a dehumidifier prevent mold?

It’s tempting just to want to put a dehumidifier to work and leave it at that. However, you’ll want to remember that a dehumidifier is a great tool to use, but it won’t fix anything. You’ll still need to focus on fresh air and using the right amount of heat, etc. A dehumidifier takes moisture out of the air, but it can only do so much to help your mold problem.

Does heating a room prevent mold?

You already know that properly heating a room will prevent mold. But what exact temperature should you be looking for? The best house temperature to prevent mold around windows and moisture-rich corners is in the low 70s F (low 20s C). If you combine that with low humidity in your home, you’ll help kick mold out just by giving it a so-called “inhospitable environment.”

Does airing out a room prevent mold?

Airing out a room will help prevent mold. That said, clean up any mold you see in that room before you air it out; otherwise, you’re spreading mold spores throughout the rest of your home, and it may lead you to have mold elsewhere!

Tips to prevent mold around windows

We’ve discussed many options so far when preventing mold around your windows. That being said, there are a few more that we need to focus on to help you become aware of common problem points.

  • Clean it up, don’t cover it up
  • Clean it up properly
  • Don’t ignore it or consider it a one-off

Clean it up, don’t cover it up

Some well-intentioned homeowners may have decided to cover up mold with a new waterproof and airtight seal around their homes. This may prevent new mold, but it won’t fix the problem. As the CDC explains, you must clean it up before fixing the issue with a new sealant! It’ll continue to grow and spread even if you can no longer see it. It also will make it hard to clean properly because you’ll need to rip up that new sealant to get to it!

Clean it up properly

Speaking of cleaning, you’ll have to learn how to clean mold from windows properly. Certain products work better than others, and you’ll want to ensure you know all about the right safety gear and post-care instructions to make that cleaning time worth it. 

Don’t ignore it or consider it a one-off

One of the biggest areas is knowingly or unknowingly seeing it as a one-time or one-off issue. It’s actually a sign of a more extensive and potentially health-hazardous problem. If you see mold in your home, always take it seriously and care for the problem and the mold itself. The mold will grow right back if you don’t solve the issue.

Window frames and sills are common areas for mold to grow. If you’re noticing mold growth around your windows, treat it by checking for any leaks, sealing them up, keeping the area clean and dry, and promoting airflow using circulation fans and fresh air. You can treat mold preventatively or after the fact, but the most important thing is to know how to keep your windows safe and free from it. The tips above will help do that with as little effort as possible.

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Rosa Peterson

Rose is the writer and creator of Better That Home, a blog about home design and decor. Rose has been designing spaces for over 10 years and writing home design and decor for big publishers. She has been inspired by many other creatives from around the world and loves to share those inspirations with her readers. Read more about Rose here