In addition to inadequate insulation, air leaks are among the largest sources of energy loss in many homes.
• Check your home for hidden air leaks by using a damp hand to detect air movement. Close all doors, windows and fireplace flues and turn off all ventilating fans to make the air leaks easier to locate.
• Caulk is most effective on gaps less than 1/4″ wide. Look for caulks that will remain flexible over a 20-year period. If it will be visible, choose a tinted caulk or one that can be painted.
• If there are large cracks and holes shielded from sunlight and moisture, try expanding foam sealant to fill them. Please buy only products listed as “ozone-safe.”
• Backer rod, or crack filler, is flexible foam material sold in long coils, with a variety of diameters available. It can be used to seal large cracks or provide backing in deep cracks to be sealed with standard caulking.
• Weather-stripping can be purchased by the foot or in kit form. There is a special kind for double doors, which are often hung with a substantial gap where they meet so the doors can swing freely. For the bottom of a door you may want to use a “door sweep.”
• Behind electric outlets and switches place insulation that has been precut for the size of outlets and switches that you have.