Window mold is a risk you must address as the weather turns wet


Mold is found everywhere. As the last link in the food chain, mold decomposes decaying organic material. Here in the Pacific Northwest, increased autumn rainfall and piles of leaves and dead wood create the perfect environment for mold growth.

T&C Glass has experts on window mold that want to help you avoid this problem. Read on for info on what you can do to stay safe as the season changes.

What causes condensation and leads to window mold?

As colonies grow, they produce thousands of airborne spores. When you open windows and doors during the last days of a long summer, these tiny spores come into your home looking for suitable habitat.

The warmer indoor temperatures, the drywall and dead wood in your window sill are all contributors to moldy environments.

Humidity describes how much water vapor is in the air. The warmer the temperature, the more water vapor the air can hold. Cold winter air can be very drying because cold temperatures do not hold much water vapor.

When the humid air in your warm house comes in contact with colder temperatures, it can no longer hold as much water vapor. This water vapor becomes a liquid. In your home, this temperature change most frequently occurs on and around your windows.

The condensation you see dripping from the window to the sill is simply your warm indoor air water vapor cooling down upon contact with your colder windows.

What can I do to minimize condensation?

You can reduce the likelihood of condensation from your windows by minimizing moisture and increasing ventilation. Here are a few useful tips to consider:

  • Use exhaust fans wherever possible
  • Vent gas burners and clothes dryers to the outside
  • Shut off humidifiers in your house
  • Be sure the venting louvers in your basement, attic or crawl spaces are open and properly sized
  • Air out your house a few minutes each day
  • Replace windows that may no longer provide effective insulation

How can I control window mold growth?

In order to survive mold needs a suitable temperature, moisture and a food source. Of those three, controlling the moisture in your home is the easiest and most effective. By lowering the humidity and eliminating excess moisture in your home, you will have less condensation.

Most windows nowadays are double-pane with air or a noble gas between the two layers. This air/gas filler helps to keep your indoor windows warmer. When you see significant condensation on your windows that sometimes means that the insulating gas is no longer doing its job and likely needs to be replaced or repaired. The lower temperature contrast between indoor and outdoor air, when your double pane windows are doing their job, reduces the likelihood of condensation on your windows.