ATTIC INSULATION
Unless your home was specially constructed for energy efficiency, you can usually reduce our energy bills by adding more insulation. Many older homes built prior to the early 1980's have less insulation than homes built today, but adding insulation to a newer home may also pay for itself within a few years.
To determine whether you should add insulation, you first need to find out how much insulation you already have in your home, where it is and what areas can benefit from additional insulation.
If requested, one of our Sunscape Solar specialists will include an insulation check as a routine part of our on-site PV Electric System evaluation. You can perform an SCE energy survey online that will help identify areas of your home that are in need of additional work or upgrade. (Before you insulate, you should make sure that your home is properly air sealed.)
In any case, you will need to find out the following:
• Where your home is, isn't, and/or should be insulated.
• What type of insulation you have installed.
• The R-value and the thickness or depth (inches) of the insulation you have.
If you live in a newer house, you can probably find out this information from the builder. If you live in an older house, you'll need to inspect the insulation yourself if you don't want an energy audit.
Inspecting and Evaluating Your Insulation
• Check the attic, walls and floors adjacent to an unheated space, like a garage or basement. The structural elements are usually exposed in these areas, which makes it easy to see what type of insulation you have and to measure its depth or thickness (inches).
• Inspect the exterior walls using an electrical outlet: 1) Turn off the power to the outlet. 2) Remove the outlet cover and shine a flashlight into the crack around the outlet box. You should be able to see if there is insulation in the wall and possibly how thick it is. 3) Pull out a small amount of insulation if needed to help determine the type of insulation. 4) Check outlets on the first and upper floors, if any, and in old and new parts of a house. Just because you find insulation in one wall doesn't mean that it's everywhere in the house.
• Inspect and measure the thickness (inches) of any insulation in unfinished basement ceilings and walls, or above crawl spaces. If the crawl space isn't ventilated, it may have insulation in the perimeter wall. If your house is relatively new, it may have been built with insulation outside the basement or foundation walls. If so, the insulation in these spaces won't be visible. The builder or the original homeowner might be able to tell you if exterior insulation was used.
• Once you've determined the type of insulation you have in these areas and its thickness (inches), see the U.S. Department of Energy's online Insulation Fact Sheet for how to determine the R-values of insulation previously installed in your home.
Types of Insulation
• 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: 2x4 walls can hold R-13 or R-15 batts; 2x6 walls can have R-19 or R-21 products.
• Loose-fill insulation—usually made of fiberglass, rock wool, or cellulose in the form of loose fibers or fiber pellets, it 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—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 2 times greater than most other insulating materials of the same thickness.
• Foam-in-place insulation—this type can be blown into walls and reduces air leakage, if blown into cracks, such as around window and door frames.
Determining Recommended R-Values
When you find out the R-values of your insulation either from an energy audit, the home builder, or your own inspection, you can then follow the U.S. Department of Energy's Insulation recommendations to determine how much insulation you should add and where to achieve the recommended insulation levels for maximum energy efficiency. Together with our years of experience, we will help insulate your home or business so you're not wasting any more energy.
Deciding What Type of Insulation to Add
If you decide to add insulation to your home, we will explain the different types of insulation available to help you decide what type to use and where. Remember that the Federal Tax Credit applies and will equate to 30% of the total cost of the installation of the insulation.
Insulation Tips
Consider factors such as your climate, building design, and budget when selecting insulation R-values for your home.
• Use higher density insulation on exterior walls, such as rigid foam boards, in cathedral ceilings and on exterior walls.
• Ventilation helps with 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. Do not ventilate your attic if you have insulation on the underside of the roof.
• 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.
• As specified on the product packaging, follow the product instructions on installation and wear the proper protective gear when installing insulation.
• Long-Term Savings Tip
One of the most cost-effective ways to make your home more comfortable year-round is to add insulation to your attic.
• Adding insulation to the attic is relatively easy and very cost effective. To find out if you have enough attic insulation, measure the thickness of the insulation. If it is less than R-30 (11 inches of fiber glass or rock wool or 8 inches of cellulose), you could probably benefit by adding more. Most U.S. homes should have between R-30 and R-60 insulation in the attic. Don't forget the attic trap or access door.
• If your attic has enough insulation and your home still feels drafty and cold in the winter or too warm in the summer, chances are you need to add insulation to the exterior walls as well. This is a more expensive measure that usually requires a contractor, but it may be worth the cost if you live in a very hot or cold climate. If you replace the exterior siding on your home, you should consider adding insulation at the same time.