Caulking

Detecting Air Leaks

It may be obvious where some air leaks occur in your home — such as an under-the-door draft — but you'll need to find the hidden gaps to properly seal your home.

Hire a Pro

For a thorough and accurate measurement of air leakage in your home, hire a qualified technician to conduct an energy audit, particularly a blower door test. A blower door test, which depressurizes a house, can reveal the location of many leaks. A complete energy audit will also help determine areas in your home that need more insulation. For more information on energy auditors or for help finding one in your area, visit the Energy Star Web site.

Do it Yourself

To find air leaks yourself, look at areas where different materials meet, such as between brick and wood siding. Also inspect around the following areas for any cracks and gaps that could cause air leaks:

• Door and window frames
• Mail chutes
• Electrical and gas service entrances
• Cable TV and phone lines
• Outdoor water faucets
• Where dryer vents pass through walls
• Bricks, siding, stucco and foundation
• Air conditioners
• Vents and fans

Other air-leak detection methods:

• Shine a flashlight at night over potential gaps while a helper observes the house from outside. Large cracks will show up as rays of light. (Note: This is not a good way to detect small cracks.)
• Shut a door or window on a piece of paper. If you can pull the paper out without tearing it, you're losing energy.

 

Application

Read and follow the instructions on the compound cartridge, and save yourself some trouble by remembering a few important tips:

• For good adhesion, clean all areas to be caulked. Remove any old caulk and paint, using a putty knife or a large screwdriver. Make sure the area  is dry so you won't seal in any moisture.
• Apply caulk to all joints in a window frame and the joint between the frame and the wall.
• Hold the gun at a consistent angle. Forty-five degrees is best for getting deep into the crack. You know you've got 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. Avoid stops and starts, if possible.
• Send caulk to the bottom of an opening to avoid bubbles.
• Make sure the caulk sticks to both sides of a crack or seam.
• 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.
• Don't skimp. If the caulk shrinks, reapply it to form a smooth bead that will seal the crack completely.

Source: www.eere.energy.gov