Before winter sets in, or in preparation for your home inspection, it's important to fix any air leaks in your home that can lead to numerous problems. When cold air is constantly seeping in, your furnace has to use more energy to heat your home, causing your gas bill to dramatically increase. Without proper heating of your home, you may be more susceptible to pipes freezing, which can be costly to repair. Take the time to perform these simple maintenance tasks and seal those gaps for good.
Since heat rises, one of the best ways to prevent air leaks in your home is to insulate weak spots in your attic and adjacent areas. In a special guide dedicated to leak sealing instructions, House Logic runs through the steps required for sealing your stud cavities. Stud cavities are often uninsulated and provide an easy outlet for hot air. For less than one dollar per square foot, purchase unfaced fiberglass insulation and pack some plastic garbage bags full of it. Then use those bags to seal the stud cavities. While you're up in the attic, you can weatherstrip the attic door. This is an often overlooked escape route for hot air.
On the inside of your home, you can tackle recessed lights, which also let a fair amount of warm air escape through gaps. Some lights already include insulation. These are called insulation contact and air tight (ICAT) lights and are labeled as such. If they are not ICAT fixtures, you can purchase an airtight baffle that fits over the light's housing. That should work to prevent any major air leaks.
Attack the gaps
Naturally, any gap has the potential to cause an air leak that you don't want. Sealing gaps between walls, doors or windows is easy with the right tools. Purchase polyurethane spray foam to deal with these. This foam will expand and harden once sprayed, so use wisely. Before it dries, it can be shaped into more uniform seal. If you're sealing gaps around window frames, make sure to buy the spray specifically for this purpose, or it could cause damage to the glass. For skinnier gaps, basic caulk should do the trick. Silicone caulk works well on nonporous surfaces or in attics where temperatures may get very low. When sealing gaps in the basement, only concern yourself with those that are above ground level. Air can't enter any gaps that are under the soil line, although you may want to seal these anyway to prevent water from seeping in. House Logic notes that in older houses, air often leaks in where the frame of the house meets its foundation. Focus on this area if you're unsure what exactly to target.
Dealing with ducts
Sometimes the warm air you cherish so much in the winter isn't just escaping to the outdoors, it might not even be making it all the way through the ductwork. If rooms far removed from the central heat source are consistently colder, a leak in the ducts may be to blame. To check for a leak, DoItYourself.com suggests lighting a match or candle and carefully running it along a duct while the heat is on. Watch the smoke trails - if they are getting blown away in a particular area, this is where you might have a leak. Feel with your hands to narrow down the exact spot.
Once you've found the culprit, you can use tape or caulk to seal it. DoItYourself.com recommends duct tape because of its easy application. Just make sure to only use high-temperature tape. Ordinary duct tape may be dangerous on hot ducts. Before placing the tape, clean the area around the leak as much as possible before applying. This will create a better seal. If the duct in question is more flat than round, caulk may do a better job. In this case, you should still do a quick wipe down on the affected area before setting the caulk. Use a metal scraper, or your finger, to make sure it's smoothly applied. Repeat this process throughout your duct system. This may be time consuming, but the energy savings and warmer house you'll have will make your effort worthwhile.