Rogue : a deceitful and unreliable scoundrel.
Seems funny to apply the word “rogue” to humidity. But during midwest winters it fits. Here’s why:
Every winter is bound to have a couple days to a couple weeks of below zero weather. When temperatures start to rise, homeowners start to notice brown spots on their ceiling that resemble roof leaks. This could be a sign of a roof leak; it could also be a sign that the home’s humidity was too high during the cold temperatures- causing attic condensation to freeze.
Many homes have humidifiers on their furnaces. Almost all new homes have this or homes with real wood floors. It’s a great thing to have, but homeowners need to be mindful of appropriate humidity levels. If the humidity is set higher than it should be during negative temperatures, the moisture rises up to the attic and before it can escape, it hits the bottom of the snow covered roof and freezes. Sometimes icicles even form off the nails! Once the weather warms up and one of the first things to thaw is attic condensation. Depending on high the humidity has been set on your house, this can be a decent amount of moisture coming down – thus causing brown spots on ceilings. It looks identical to spots from roof leaks.
What is the appropriate level of humidity for your home?
If the outside weather is…
- 20 to 40 degrees, humidity should be less than 40%
- 10 to 20 degrees, humidity should be less than 35%
- 0 to 10 degrees, humidity should be less than 30%
- -10 to 0 degrees, humidity should be less than 25%
- -20 to -10 degrees, humidity should be less than 20%
- below -20 degrees, humidity should be less than 15%
This will prevent attic condensation, mold, or any other issues caused by overly humid and warm air.
What about you?
These guidelines are the optimal levels to make your home comfortable, but what about the people living in it? Dryer air is not always the best for us to live in but there are ways to keep both you happy and your home comfortable. Instead of using whole house humidifiers use individual ones when you are using the room. Use programmable timers to turn on and off humidifiers. Buy indoor humidity sensors – these range from $5-$50. Click here to see the “indoor hygrometers” on Amazon.com
It’s so easy to forget to monitor or change your humidity. Many people don’t even realize this is what’s going on until it’s too late – brown spots appear! If this happens to you, don’t panic but it’s still good practice to have a trusted roofer inspect to confirm no roof leaks.