Air Leaks & Insulation

Improving your home's insulation and sealing air leaks are the fastest and most cost-effective ways to reduce energy waste and make the most of your energy dollars. Be sure to seal air leaks before you insulate because insulating materials won't block leaks.

Sealing Air Leaks

Air leaks can waste a lot of your energy dollars. One of the quickest energy-and-money-saving tasks you can do is caulk, seal and weather strip all seams, cracks and openings to the outside.

Tips for Sealing Air Leaks

  • Test your home for air tightness. On a windy day, carefully hold a lit incense stick or a smoke pen next to your windows, doors, electrical boxes, plumbing fixtures, electrical outlets, ceiling fixtures and other places where air may leak.
  • Caulk and weatherstrip doors and windows that leak air.
  • Caulk and seal air leaks where plumbing, ducting or electrical wiring comes through walls, floors, ceilings and soffits over cabinets.
  • Install foam gaskets behind outlet and switch plates on walls.
  • Seal air leaks around fireplace chimneys, furnaces and gas-fired water heater vents.
  • Replace door bottoms and thresholds with ones that have pliable sealing gaskets.

Sources of Air Leaks in Your Home

  • dropped ceilings
  • attic entrance
  • water & furnace flues
  • door frames
  • window frames
  • plumbing & utility access

  • recessed lights
  • sill plates
  • all ducts
  • chimney flashing
  • outlets & switches


Insulation is made from a variety of materials and it usually comes in four types: rolls and batts, loose-fill, rigid foam and foam-in-place.

The type of insulation you should choose depends on how you will use it and on your budget. Consult a professional insulation installer to decide what type of insulation is best for you.

Insulation Tips

  • Consider factors such as your climate, home design and budget when selecting insulation for your home.
  • Use higher R-value insulation, such as spray foam, on exterior walls and in cathedral ceilings to get more insulation with less thickness.
  • Install attic air barriers such as wind baffles along the entire attic eave to help ensure proper airflow from the soffit to the attic.
Source: Energy Star