Weatherization

Sealing your home with caulking and weather stripping is one of the most cost-effective ways to reduce energy waste. Caulking seals cracks and joints in the house. Weather stripping reduces air infiltration around moving parts of the house, such as doors and windows. Caulking and weather stripping will alleviate drafts and help your home feel warmer when it is cold outside, but these weatherization techniques do not replace the need for proper insulation throughout your home.

VENTILATION IS IMPORTANT
Sealing air leaks in a home, without proper ventilation, can also seal in indoor air pollutants. Therefore, any plan to tighten the thermal envelope of a home should be accompanied by an evaluation of the home's ventilation needs. Active ventilation may be needed to provide fresh air.

WHERE ARE THE AIR LEAKS?
Look at areas where different materials meet, like between brick and wood siding, between foundation and walls, and between the chimney and siding. Also inspect around the following for any cracks or gaps that could allow air leakage:

• Door and window frames
• Mail chutes
• Electrical and gas service entrances
• Plumbing penetrations
• Cable TV and phone line entrances
• Outdoor water faucets
• Dryer vents
• Bricks, siding, stucco, and foundation
• Air conditioners
• Vents and fans

For a more accurate measurement of air leakage, hire a home performance technician to conduct a blower door test in your home.

CAULKING
Caulk forms a flexible seal for cracks, gaps, or joints that are less than one quarter-inch wide. In addition to plugging air leaks, caulking can also prevent water damage inside and outside the home when applied around water pipes, ceiling fixtures, and plumbing fixtures.

Application
Although not a high-tech operation, caulking can be tricky. It is best applied when outdoor temperatures are between 50° and 65°F, when most building materials are at the midpoint of contraction and expansion and differences between indoor and outdoor temperatures are minimized. Read and follow the instructions on the compound cartridge. Avoid trouble by remembering a few important tips:

• Clean and dry all areas to be caulked for good adhesion. Remove any old caulk and paint, using a putty knife or a large screwdriver.
• Hold the gun at a consistent angle. Forty-five degrees is best for getting deep into the crack. You have the right angle when the caulk is immediately forced into the crack as it comes out of the tube. 
• Caulk in one straight continuous stream, if possible. Avoid stops and starts. 
• Send caulk to the bottom of an opening to avoid bubbles. 
• Release the trigger before pulling the gun away to avoid applying too much. A caulking gun with an automatic release makes this much easier. 
• If caulk oozes out of a crack, use a putty knife to push it back in. 
• Make sure the caulk sticks to both sides of a crack or seam.
• Don't skimp. If the caulk shrinks, reapply it to form a smooth bead that will seal the crack completely.

WEATHER STRIPPING
Weather stripping can seal leaks around movable joints, such as windows or doors. The weather stripping you choose should seal well when the window or door is closed while allowing it to open freely. You need to choose an appropriate product for each specific location. The weather stripping will need to withstand the friction, weather, temperature changes, and wear and tear associated with its location.

Application
Weather stripping supplies and techniques range from the simple to the technical. Consult the instructions on the weather stripping package. Here are a few basic guidelines:

• Weather stripping should be applied to clean, dry surfaces in temperatures above 20°F (-7°C).
• Measure the area to be weather stripped twice before cutting anything.
• Apply weatherstripping snugly against both surfaces. The material should compress when the window or door is shut.