Insulation provides an important barrier against both the cold of winter and the heat of summer. Improving attic insulation is one of the best energy-efficiency investments, according to the U.S. Department of Energy.
Get out the ruler
To assess your attic insulation, measure the thickness of the insulation, and decide what type of insulation you have. If you’re not familiar with the type of insulation, take a small sample to your local building supply store to ask for help in identifying it.
The effectiveness of insulation is measured in R-value per inch. The total R-value of your insulation depends both on its type and its depth. To determine the total R-value of your insulation, decide what type of insulation is installed, and multiply the R-value per inch times the number of inches installed. Cellulose loose-fill insulation, for example, is rated at about R-3.5 per inch. If your attic has 4 inches of cellulose, that’s 3.5 x 4 = R-14. In Kentucky it is recommended that attic insulation should be between R-38 and R-49.
Consider your options
The higher the R-value, the better your walls and roof will resist the transfer of heat. Although insulation can be made from a variety of materials, it usually comes in four types. Each type has different characteristics:
• Rolls and batts—or blankets—are flexible products made from mineral fibers, such as fiberglass and rock wool. They are available in widths suited to standard spacings of wall studs and attic or floor joists.
• Loose-fill insulation—usually made of fiberglass, rock wool, or cellulose—comes in shreds, granules, or nodules. These small particles should be blown into spaces using special pneumatic equipment. The blown-in material conforms readily to building cavities and attics. Therefore, loose-fill insulation is well-suited for places where it is difficult to install other types of insulation.
• Rigid foam insulation typically is more expensive than fiber insulation. But it’s very effective in buildings with space limitations and where higher R-values are needed. Foam insulation R-values range from R-4 to R-6.5 per inch of thickness, which is up to two times greater than most other insulating materials of the same thickness.
• Foam-in-place insulation can be blown into walls and reduces air leakage.
If your home has you shivering, there’s another incentive to add more insulation.
Through a new federal program, homeowners may be able to put a few extra dollars in the piggy bank. The Energy Policy Act provides federal tax credits to consumers who make certain specified energy-efficient upgrades to their homes in 2006 and 2007.
• Consider factors such as your climate, building design, and budget when selecting insulation R-values for your home.
• Use higher-density insulation, such as rigid foam boards, in cathedral ceilings and on exterior walls.
• Ventilation plays a large role in providing moisture control and reducing summer cooling bills. Attic vents can be installed along the entire ceiling cavity to help ensure proper airflow from the soffit to the attic to make a home more comfortable and energy efficient. Check with a qualified contractor.
• Recessed light fixtures can be a major source of heat loss, but you need to be careful how close you place insulation next to a fixture unless it is marked IC—designed for direct insulation contact. Check your local building codes for recommendations.