During Winnipeg’s frigid winter months—where temperatures regularly plunge below -30°C and the wind howling across the flat prairie feels like it carries straight from the Arctic—the experience of having frost or ice encroach into your home’s interior is not an uncommon one. Indeed, for some longtime Wolseley or West Broadway residents, the sight of frost on original wood windows may even be nostalgic, a reminder of the city’s historic housing stock built during the boom years of the early 1900s.
Romantic notions of Jack Frost aside, ice buildup on and around windows is not simply something to accept or ignore, especially in a city where Environment Canada issues extreme cold warnings multiple times each winter. As a homeowner in the Red River Valley, it’s essential to be aware that this phenomenon can lead to aesthetic and structural damage that needs to be addressed proactively before the spring thaw reveals warped frames or water-stained drywall.
At Nisby Home Renovations, we’ve helped countless Winnipeg homeowners—from St. Boniface to St. James, River Heights to the North End—improve the efficiency of their homes while reducing or eliminating frost and ice buildup on windows. Whether you’re in a century-old character home near Assiniboine Park or a mid-century bungalow in Fort Richmond, the principles remain the same. Below, we’ve taken a closer look at what causes ice buildup on windows and how to effectively mitigate the issue in Winnipeg’s unique climate.
Key Takeaways
- Frost and ice buildup on windows is a common phenomenon in the winter months, but that doesn’t mean it should be ignored.
- If not properly addressed, ice buildup can cause damage to window frames, walls, finishes, window mechanisms, and more. In some cases, it can even crack or shatter a window pane!
- Mitigate ice buildup on windows by maintaining an ideal relative humidity range inside your home based on the temperature outside. Check gas appliances, repair plumbing leaks, maintain a warm indoor temperature, and keep rooms well-ventilated.
- Replace aging or damaged windows with help from the experts at Nisby Home Renovations to ensure greater home efficiency and reduce frost and ice buildup!
What Causes Ice Buildup On Windows?
Ice buildup on windows is caused by condensation—the process that occurs when water vapour in the air changes from gas to liquid. Warm interior air meeting a cold window with a surface temperature below the dew point causes water vapour to condense into tiny water droplets and accumulate as fog or moisture on the window pane.
When outdoor temperatures dip below zero—which in Winnipeg can happen from October through April, with January averages hovering around -16.4°C—liquid condensation freezes into tiny ice crystals, perpetuating the buildup of frost and ice. Because house windows typically have less insulation than walls, they are particularly prone to icing up during cold snaps.
Winnipeg’s location in the Red River Valley creates unique challenges. The valley’s topography can trap cold air, creating temperature inversions that keep surface temperatures lower than in surrounding prairie areas. Combined with older housing stock common in neighborhoods like Crescentwood or Osborne Village—where original windows may be 50 to 100 years old—this makes interior ice buildup a particularly prevalent issue for local homeowners.
What Happens When Ice Builds Up?
Winter condensation on windows can range from frosty zigzags that appear on certain panes when moisture levels increase (during cooking activities or after showering, for instance) to severe ice buildup that continually obscures the view, spreads to nearby frames, sashes, or walls, and threatens to damage the aesthetic and structural integrity of your home.
Below, we’ve listed some of the problems that can arise when ice accumulates on and around windows over time:
- Continual thawing and freezing can lead to a buildup of liquid that causes wood window frames to warp, paint to crack, and finishes to become discoloured.
- Frost and ice accumulation can damage window mechanisms, including the locking system, the window seals, and more.
- Window frames and walls can be exposed to moisture that leads to the formation of mould and mildew.
- Moisture that seeps into poorly sealed window frames and subsequently freezes can lead to the cracking or even shattering of window panes!
Preventing Ice Buildup On Your Windows
Many factors can influence ice buildup on windows, including the age and construction of your house and the efficiency of your windows. In Winnipeg, where heritage homes with single-pane windows coexist with newer builds, solutions vary by property. That being said, reducing humidity within your home is one of the most critical aspects of keeping frost and ice at bay.
Relative humidity refers to the level of moisture in the air in relation to the maximum level of moisture the air can hold at a given temperature. The colder the temperature drops outside—and Winnipeg’s record low of -47.8°C set in 1879 reminds us how extreme it can get—the lower the relative humidity of the air inside your home will need to be in order to prevent condensation buildup on your windows. According to Health Canada, the inside air in your home should ideally have a relative humidity between 30%-35% in the winter months (potentially even lower during extreme cold snaps like those we experienced in February 2021). Relative humidity can be measured with a hygrometer, available at local hardware stores like Rona on Regent Avenue, Home Hardware on Portage Avenue, or Canadian Tire locations across the city.
Simple adjustments such as covering boiling pots on the stove, using the bathroom fan when showering, and putting clothes in the dryer instead of hanging them on a line in the laundry room can contribute to lowering indoor humidity levels. Here are some other measures you can take to prevent ice from forming on the insides of your windows:
Check Your Gas Appliances
From furnaces and water heaters to gas fireplaces and cooktops, improperly operating gas appliances can lead to excess water vapour in the air. Given that Manitoba Hydro serves the Winnipeg region, ensuring your gas appliances are properly vented and maintained not only prevents condensation issues but keeps your home safe and your energy bills manageable during those long heating seasons
Check And Repair Plumbing Leaks
Even small plumbing leaks, such as a dripping faucet, can lead to an increase in indoor humidity levels. In older Winnipeg homes—common in areas like the Exchange District or West End—aging plumbing systems may develop slow leaks that go unnoticed until ice buildup on windows signals a larger problem.
Use A Humidifier Properly
A humidifier can help prevent the dry skin and static electricity that plague Winnipeggers through the dry winter months, but be sure to monitor it carefully. During extreme cold warnings, when the mercury drops below -25°C, you may need to reduce humidifier use significantly to prevent window condensation.
Maintain A Reasonably Warm Temperature
Maintaining a relatively warm temperature inside your home—particularly important during Winnipeg’s notorious February cold snaps can help prevent condensation from turning into frost and ice. Manitoba Hydro recommends keeping your thermostat at a consistent temperature to avoid the freeze-thaw cycles that damage window frames.
Keep Your Rooms Ventilated
Proper ventilation promotes evaporation and helps prevent excess moisture from icing up windows. Consider investing in a heat recovery ventilator (HRV), particularly valuable in Winnipeg’s climate where it can recover heat from outgoing air while bringing in fresh air. Use exhaust fans when cooking or showering, and keep air ducts, HVAC filters, and exterior vents clean especially important after autumn leaf fall or winter snow accumulation that can block vents.
