What It Means and How to Handle It

Have you ever noticed water droplets forming on the inside of your windows or sliding glass doors during the colder months — sometimes even freezing into a thin layer of ice? You might think there’s something wrong with your windows or that they need immediate repair. But before jumping to conclusions, it’s important to understand what causes this phenomenon — and how to address it properly.

What exactly is condensation?

Condensation occurs when warm, moist air comes into contact with a cold surface , such as window glass or sliding door panels. As the warm air cools, it can no longer hold the same amount of moisture, so the excess water vapor turns into liquid droplets — a process known as condensation.

This is especially common in winter, when indoor air is warm and humid, while outdoor temperatures are significantly lower. The result? Water droplets appear on the inside of your windows and doors.

Why does condensation form on windows and doors?

There are several factors that contribute to condensation:

• Temperature Differences: when warm indoor air meets the cooler surface of the glass, condensation naturally forms.
• High Indoor Humidity: everyday activities like cooking, showering, doing laundry, or even breathing increase the humidity levels in your home — all of which raise the chances of condensation.
• Poor Ventilation: if rooms lack proper airflow, moist air has nowhere to go, leading to buildup and increased condensation.
• Inadequate Insulation or Damaged Seals: old or poorly sealed windows and doors allow cold air to enter, further cooling the interior surfaces and promoting condensation

Are windows or doors actually to blame?

It’s easy to point fingers at your windows or doors, but in most cases, they aren’t the problem . They simply act as indicators — showing where moisture is collecting due to environmental conditions in your home. Even high-quality windows can experience condensation if humidity levels are too high or ventilation is lacking.