Condensation on Windows: What You Can Do About It | Ep. 150

Today's Homeowner Podcast

Condensation on windows causes more than unsightly wet glass. It can lead to bigger problems. That’s why Marvin, from Alabama, needs help.

“Our double-pane 20-year-old windows produce lots of moisture every time the outside temperature drops below 45 degrees,” he says. “The moisture then drips down on the wooden windowsill.”

Marvin says the water seems to be mostly on the very bottoms of the windows, and his wife wipes it off with a rag each morning to prevent rot on the windowsill.

This couple has a humidity issue. When the outside temperature is below 40 degrees Fahrenheit, the inside humidity should be between 25% and 40%. You can measure humidity with a simple battery-operated hygrometer that costs less than $20.

Once you’ve identified the problem, you need to do something about it. In this case, that could mean running the heating system more often to mitigate the humidity issue.

If you’re seeing condensation at the bottom of the window’s upper and lower sashes, air could be leaking in. So, make sure the weatherstripping is doing its job, or add new weatherstripping.

And don’t forget to use your range hood in the kitchen and bathroom vent fans to keep the humidity down.

Finally, you can always purchase a dehumidifier to counter the problem.

Listen to the Today’s Homeowner Podcast to learn more about this issue and other home maintenance chores.