Tips For Fixing and Preventing Sweating Windows

When the planet turns and winter comes, many homes start to see condensation on their windows. We close our doors and windows to shut out the cold, affecting ventilation and increasing humidity levels like a pot with its lid on, and our windows sweat as a result.

If left unattended, sweaty windows can start to look bad, and worse, structural damage such as wood rot is possible.

Windows aren't shy about sweating, so chances are you'll notice visible moisture on window panes or pooled on the sill during the colder months, thanks to the difference in temperature indoors and out. If it's really frosty where you live, the condensation can freeze, worsening the blocked view. When the water gets into the wood and then freezes, the wood will expand and crack.

Property hunting in summer? You might not see the sweat in action, but you can watch for other damage indicators. Window frames may look swollen or warped, metal may appear rusty, and mold and mildew are telltale signs of too much moisture in the environment and potential respiratory issues.

If the problem has yet to advance to visual deterioration, there's a lot you can do to prevent the damage. For starters, you can open windows slightly and keep drapes open too. You don't have to keep your bedroom windows open on an icy evening but crack them after you wake up. While you were sleeping, warm breath would have caused sweaty windows, and fresh air can eliminate condensation on any susceptible surface, including within closets and on walls.

In addition to ventilation, you must diligently wipe the windows down with a microfiber cloth or window vacuum. Use a dehumidifier to dry the air further.

Adding weatherstripping to windows and doors can prevent the cold air outside from coming in and makes your place more energy efficient. Vinyl is generally an excellent moisture-resistant choice of weatherstripping material, but you can consult an expert at your local home improvement store for tailored recommendations.

While window films don't address the root cause of the moisture, they offer affordable insulation in rental properties where the landlord might want to avoid investing in double-glazing.

Storm windows and double-pane windows will help your cause, but triple-pane is even better and may be worth the splurge. The improved thermal insulation means the glass and the surrounding air are similar in temperature, which keeps water droplets from forming.

You can also invest in a window with warm-edge technology. Do a cost-benefit analysis beforehand to make the most efficient choice for your budget.

Addressing humidity levels is the first step in any plan to combat window condensation. You want to aim for humidity levels between 15% and 40% and use a hygrometer to test the levels. You can adjust humidity with heating or air conditioning, extractor fans, clean furnace filters, and ventilation systems.

Choose between natural and whole-house mechanical ventilation systems. The former is more economical and uses openings to create airflow, but many energy-efficient homes use mechanical ventilation with its more effective duct, fans, and exhaust systems, and better air quality. If you're weatherizing your home, mechanical ventilation is usually the best bet.

Exhaust your natural options first. Buy some house plants that love moisture and humidity. Indoor plants such as orchids and bromeliads suck moisture from the air and look much nicer than a dehumidifier. Opt for the pop of green; it could be the simple change you need.

Where do you do your laundry? If it's in an airless basement, insufficient ventilation will cause condensation. Use a fan, desiccants (materials that suck up moisture, like the silica packets in your shoes), and clean filters.

If you only have a washing machine and not a drier, line dry clothing outside or in an upstairs room with open windows or a dehumidifier.

In the kitchen, put lids on your boiling pots and make good use of that oft-forgotten extractor fan. Keep moisture contained in bathrooms and kitchens by closing doors to other rooms but keeping windows open. These small measures make more of a difference than you'd imagine.

If you've tried affordable, quick fixes like DIY window film and they haven't helped, you need to consider calling the pros, especially if there's structural damage. You can get multiple quotes or opinions to get a fuller picture of what is wrong and the best way to address the matter in the short and long term. For example, an expert can assist with condensation inside double-glazed windows and other issues tricky to tackle on your own.