Why Does Mold Build Up on Window Sills?

Written on: June 12th, 2015 BY IN Windows

Now that it’s summertime and the temperatures are warmer, you may be opening your windows more to let in a breeze. Have you noticed mold on the sills? You aren’t alone! “Why do my window sills get mold?” is a question many homeowners ask.

If you need to replace your old, moldy windows, contact Overhead Door Co. of Indianapolis & Muncie today—or keep reading to learn more about this unsightly problem.

Causes of Mold Build-Up

Mold thrives in damp, dark environments. Moisture is the primary reason mold develops on window sills—but how does water get in?

Water builds up on the inside of your windows from normal daily activities, including:

  • Bathing
  • Washing dishes
  • Washing clothes
  • Humidifying

Everyday tasks aside, other reasons water can build up on the sills are:

  • Old, leaky windows
  • Poorly installed windows
  • Structural problems (although this is rare)

So what can you do?

Prevent Mold on Window Sills

There are things you can do to help prevent mold growth on your windows. Try:

  • Letting in sunlight when possible: Open the shutters, curtains and blinds. Even raising the blinds a few inches can not only let in light but also help with air circulation.
  • Circulating the air near your windows: Increasing the air circulation near the window surfaces can help prevent warm, moist air from becoming stagnant around the cold surface where the condensation can occur. Ceiling fans or even smaller tabletop fans can help with this.
  • Reducing moisture in the air: Use exhaust fans and consider using a dehumidifier if moisture buildup is excessive in your home (often do large loads of laundry? Cook every night?). Also be sure to open the windows sometimes.
  • Manually removing water: When you clean your house, don’t neglect the windows. Using a dry cloth, wipe the window sills dry. If you have older windows that aren’t as airtight, it may be beneficial to do this on a weekly basis.
  • Replacing your windows: If you have a lot of water on the sills—more than seems normal—it may indicate a leak. If your windows or leaking or just old (ones made even 10 years ago aren’t as airtight and energy-efficient as those manufactured today), replacing them is a good idea. New windows can help you save money and live more comfortably.

Window Replacement in Indianapolis

Do you need new windows for your home? If you live in central Indiana, make Overhead Door Co. of Indianapolis & Muncie your first call. We offer high-quality vinyl windows in all different styles (casement, awning, double-hung, slider and more). Check out our window specials and get in touch with our team today!