Skylights allow natural light into indoor areas, minimizing the use of overhead lighting and lowering energy expenses. They also promote ventilation and remove odors from kitchens and bathrooms. Though they typically don’t require much skylight cleaning, they may develop condensation, making interior areas damp and musty. Here’s a guide to why this happens and how to fix it.

What Causes Skylight Condensation?

Skylight condensation occurs when warm, moist air comes into contact with cold glass. More specifically, it happens when relative humidity levels rise

Your fans or HVAC system will carry excess water vapor to windows, where it sticks to the glass. This may result in moisture on both the pane and the surrounding frame. 

skylight cleaning

Indoor humidity levels typically rise and exacerbate condensation after you use showers, tubs, or stoves. Additionally, the water vapor in human breath and sweat can create condensation in rooms that contain skylights. 

How Can You Fix It?

Seal gaps and cracks around your skylights with caulk or weatherstripping to ensure that they do not allow humid air indoors. Allow a skylight cleaning professional to remove leafy debris, trapped moisture, and other obstructions from the flashing to prevent excess water from collecting on the glass. Repeat these maintenance steps a few times per year.

Prevent condensation by using exhaust fans to move warm and humid indoor air outdoors. Increase ventilation by opening windows or using fans after using water fixtures and appliances. Keep shades open to allow the sun’s heat to dry up excess indoor moisture.


Keep your skylights dry and clear with cleaning and maintenance from Squeeky Clean Window Washing. They provide residential and commercial window washing and power-washing to clients throughout Montgomery County, MD. Call (301) 424-4020 to set up a regular skylight cleaning schedule for your property, or visit their website to request an estimate.