Why is there ice on the inside of my windows and how can I stop a major ice buildup?

Why is there ice on the inside of my windows and how can I stop a major ice buildup?
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3 months ago
Reviewed by Bryan Baeumler

Waking up to freshly fallen snow during winter months can bring back warm and beautiful memories of childhood. You may remember trying to look out your home’s frosted windows, longing to build a snowman or throw snowballs with your friends. 

Canadian winters can be truly magical, but as an adult, you would know that the frigid temperatures can also be especially tough for your home, particularly your windows. Even in a sealed house, ice buildup on windows can be a problem, which can present issues beyond the winter season. 

Why does ice buildup on my windows, anyway? 

There are many forces at work in the harsh Canadian climate, but here are some causes that you should look out for: 

  1. Water vapor: When temperature drops outside to below zero, the water vapor or moisture in the air is drawn towards the window pane. When its surface goes beyond the “dew” point, the vapor quickly changes from gas to water droplets and can rapidly freeze into ice crystals.
  2. Humidity:Humidity is the actual measurement of moisture or water vapor in the air. Decreasing humidity levels in your home can help to stop your windows from getting frosty, but it does not guarantee that the problem will be gone.
  3. Air leakage & poorly performing windows:While windows act as a barrier to keep your interiors warm, they may soon start to leak air. Some reasons could be because they were not installed properly, or they may already be worn down or damaged due to age. 

What can happen if ice continues to buildup? 

Having ice on your windows can present not only aesthetic problems, but also structural and safety concerns. 

For one, it can cause long-term damage to your windows. Wood can be warped by moisture, and can potentially lead to cracks in the glass. These can even worsen your air leakage problems, making it turn for the worse in the coming cold climates. 

When the frost melts, the water can cause the paint to crack, allowing the wood to eventually rot and cause mold and mildew around your windows. The presence of mold can lead to health concerns, as these irritants can cause problems to your lungs and respiratory system. 

Finally, since your cold and leaky windows are already not functioning in the way they should, expect your energy costs to go up as you desperately try to warm up your house. Cranking up the thermostat can comfort you in the short term, but just thinking of the skyrocketing energy bill can probably cause your heart to freeze up, too. 

New window cost

Here Are 10 Ways to Prevent Ice Buildup on The Windows of Your Home 

Luckily, you don’t have to wait for all of the negative things to happen before you should act. Knowledge and preparation are keys, so here are a few tips to keep the ice at bay and for you to fully enjoy those great winter moments: 

  1. Turn on your exhaust fans. There will probably be plenty of cooking during the winter season, so make sure to turn on those fans to expel excess moisture from the air. Remember, we want to lessen the moisture inside the home, so they don’t cause any more problems. Just make sure that the fans blow outside your home. On milder days, you can also open your windows.
  2. Use a dehumidifier. Since the excess of humidity can cause the ice to crawl up your windows, you may want to use a dehumidifier to lower those levels. While usually dehumidifiers are a thing of summer months, they can also give the same results during colder months.
  3. Open your curtains and/or blinds. While you may want to keep your privacy and ensure more insulation, doing this will allow the air to circulate against your windows and reduce the moisture that might lead to frost. Cooler air can get trapped near the glass when you have heavy drapes and shades, and when moisture is drawn towards the window, that will lead to ice buildup.
  4. Refrain from drying your clothes inside your house. Again, this will introduce additional moisture in the interiors of your home. If you cannot avoid hanging your clothes up inside your house, consider removing the majority of the water first through the use of a clothes dryer. Also, ensure that your laundry room has proper ventilation. Poorly installed vents can lead to increased humidity levels.
  5. Keep your home warm enough. Hit two birds with one stone: while keeping yourself warm and cozy, it may be beneficial for your windows to increase your room temperature, especially during the night. You may also use a space heater in rooms where frost builds up easily on the windows.
  6. Seal with caulking. Or you can also apply weather stripping. Caulking is a material that is used to seal joints or seams against leakage. While this may be a temporary solution, seal any small leaks or gaps that you find around the windows can be a big help during the cold months. Alternatively, you can also secure weather stripping around your windows, by applying this to the bottom of your window sash and along areas and seams where windows open and close.
  7. Install plastic insulation. Another option is to place a plastic shrink film on the inside of your windows using a double-sided tape. While it may haze up your view, it can help provide more insulation for your home and reduce condensation collecting on the glass. You may find these window insulation kits, complete with the plastic shrink film and the tape, at most hardware stores.
  8. Consider installing a heat recovery ventilator (HRV) system. An HRV system works by taking moist and stale air from your room and supplies clean and filtered air for a certain time period. However, should the condensation begins to build up, you may need to adjust the settings on this system.
  9. Think about replacing your windows with double- or triple-pane ones. Replacing single-pane windows with double- or triple-pane units can provide enough insulation during the cold winters, and will save you enough money on your energy costs in the long run. When replacing your windows, consider those that are high-performance and are Energy Star-certified, so you can be assured that you are getting energy efficient windows. New window technology, such as argon gas or Low-Emissive coatings, can also help insulate your windows against air leaks and heat loss.
  10.  Consult a professional. Still unsure of the reason behind the icy buildup? Maybe it’s time to call a professional. There can be several causes behind the frost, and a set of trained eyes with years of expertise can help allay your worries and help you enjoy the winter months without much worry. 

While the winter season in Canada can be unforgiving at times, it can still be the most wonderful time of the year. So don’t let the frost bite at your chances to relive your warm, happy memories. Now that you know that winter is coming, it is best to be prepared to address any issues on ice buildup early on to ensure a fun and memorable winter season for you and your family.


Julia Gurevich
Julia Gurevich

Julia Gurevich is a versatile content writer with a passion for delivering captivating narratives through a diverse and attentive approach. Her eye for detail helps her craft content that resonates with audiences across varied home improvement industries, capturing the perfect balance between information and entertainment. As a content coordinator, Julia takes pride in delivering content that leaves a lasting impact through her ability to navigate seamless content strategies and collaborative projects between teams. In her free time, she enjoys exploring Toronto’s cultural landscape, visiting local parks, and getting to know members of the community through events and activities.

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