With winter lurking just around the corner, it’s important to keep your home properly sealed.
Air leakage can create issues in any climate, but leaks in cold weather can rack up heating
bills, cause drafts, and freeze pipes. The best way to avoid damage and inconvenience is
prevention—so we’ve laid out the basics of sealing your home.
Identifying Air Leaks
The most accurate assessment of a home’s efficiency is with an energy audit or blower door
test, usually done by a hired professional. However, you can still assess your home for air
leaks with a thorough inspection.
Inspecting your home
Check your home’s exterior for any source of leakage. Air leaks are most likely to occur
where different materials meet, such as
Junction of foundation and exterior
Any protruding outdoor structures (sinks, hoses, windows)
Inspect the interior of your home for these other common sources of air leaks:
Frames of windows and doors
Vents and fans attached to walls
Outlets—electrical, cable, Ethernet, etc.
Weather stripping around doors
Window and door frames are frequent culprits of leakage. Start inspecting these by testing
them for movement and listening for rattling noises. If the frame can shift—even if only when
pressing on it—it could have a leak.
Sealing air leaks
If you think you’ve identified most of the leaks in your home, you can seal them with caulk or
weatherstripping. Caulk works best for immovable objects like cracks or gaps in siding (less
than ¼ inch wide) and leaks around ceiling fixtures, pipes, bathtubs, etc. Weatherstripping is
designed for movable objects like doors and windows that open.
Basic application techniques
Before applying anything, be sure the area is clean and dry to prevent trapped
moisture, and use a scraper to remove old paint or caulk.
Cut the tip of the caulk cartridge at a 45-degree angle.
Trial using caulk on a disposable surface if you’ve never used it before.
Clean up mistakes with a damp rag.
Allow about 24 hours for caulk to cure and follow all instructions on the package.
“Air Sealing Your Home” U.S. Department of Energy (energy.gov/energysaver/air-sealing- your-home)