You’ve probably tried to weatherproof your home before by tucking rubber weather stripping around your windows or by using an under-door seal to close the gap between the bottom of a door and the threshold of a doorway.
But did you know there are more than a dozen other places inside a house where air and moisture typically sneak in?
According to the U.S. Department of Energy (DOE), there are 19 trouble spots to look for in your home, including air ducts, attic access points, shafts for piping or ducts, porch roofs, and fireplace walls.
If your house isn’t properly weather sealed—conditioned air is escaping and outside air is getting in without you controlling it—three things can happen:
- You’ll be less comfortable. Your house will be draftier and have more cold or hot spots. You’ll pay more for heating and cooling. As conditioned air escapes, your HVAC system will have to work harder to keep the air at temperature.
- You may face problems with mildew or mold. When outside air sneaks in, so will moisture.
How should you seal all the gaps?
First, DOE recommends that you hire a weatherization expert, such as an energy assessor, to test and make sure your home is airtight. Once you get a report, you’ll know which leaky areas to attend to.
Once you know where the gaps are, get your caulking gun ready! In addition to sealing up gaps around windows and doors, seal around any spot where plumbing, electrical, or ducting comes through walls or ceilings. (You can use a foam sealant for wider gaps.) Invest a bit of time to install foam gaskets behind all outlet and lightswitch plates.
You should also pay attention to windows, replacing single-pane windows as you’re able with double-pane or other types of windows that keep outdoor air outside.
And if you have a chimney, plug the flue when it’s not in use using a flue blocker or inflatable chimney balloon.
What about ventilation?
Air leakage is not a replacement for proper ventilation in your home. That’s because you can’t control how much air is entering or escaping—or when it’s happening.
When too much air comes in, typically when it’s cold and windy, the air temperature drops or rises beyond your comfort level. When not enough air enters from the outside, typically when it’s warm and stagnant outside, humidity levels indoors can rise, encouraging mold or mildew to form.
The answer is to close up the leaks and create proper ventilation throughout your home. (Again, an energy assessor can give you recommendations for your home.)
Overall: seal up the leaks and ventilate properly for a less drafty, less expensive season.