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Insulating your attic makes good cents

Typical attic access insulated box cover
Typical attic access insulated box cover
Battic Door

Many older homes contain less insulation than what is typically recommended by today’s standards. Unless your home was recently built, it may be a good idea to check the amount of insulation in your attic. At the same time you may also want to check out your attic access (hatch opening or pull down stairs) if you have one, as this area is generally not insulated at all.

Most attics in the Atlanta area have had lose fiberglass or cellulose material blown in by the contractor when the house was originally built. This generally accounted for 4-6 inches of insulation. Properly installed, blown in fiberglass has an average R-value of 2.9 per inch of depth. If you were lucky, and the contractor applied a consistent thick layer of insulation, you will find you have about 6 inches of insulation when you measure the depth. This translates into a cumulative R-value of 17.4 and does not meet current energy efficiency standards.

The U.S. Department of Energy’s recommended R-value for the Atlanta area is in the range of R-30 to R-36 for a typical attic. Based on this information, most homes need an additional layer of attic insulation, as potentially 30% of a homes heat can be lost through the roof. Since an additional roll of fiberglass blanket has an insulation value of somewhere between R-15 to R-19, your cumulative insulation total would increase to approximately R-32.4 to R- 36.4.

This is a relatively cheap upgrade to your home’s energy efficiency and the payback period is somewhere between 3-5 years, depending on your homes design specifics. You should also check out the tax advantages that may apply to such an investment as they will certainly help.

As mentioned above, your attic access often goes un-insulated and can represent one of the biggest deficiencies in the thermal barrier between your attic and your conditioned living space. A typical ¼” gap around the perimeter of the access opening can potentially leak 100 cubic feet per minute (cfm), 24 hours a day. This is heated air going straight up to your attic, representing a hole in your ceiling. This also introduces air moisture into your attic which can lead to other problems.

A simple solution to this is a light weight movable cover box that can be positioned over the pull down staircase. You can easily build one of these yourself or purchase a kit from a weatherization supplier. The Oak Ridge National Laboratory actually provides step by step procedures for sizing and building your own access covers whether it is for a pull down staircase opening or a smaller hatch opening.

You may also want to investigate weatherization suppliers, such as Battic Door to purchase a light weight, insulated cover box. They have standard size kits ready for purchase at economical prices. These units provide a custom snug fit over your attic opening and are light weight so they can easily be moved to one side. This should help eliminate drafts up through your attic thereby increasing your comfort level through the heating and cooling seasons.

Please contact me with ideas, subject matter, questions, or new technologies that you would like to see discussed in future editions. Saving tomorrow begins today.

“In the end, we will conserve only what we love, we will love only what we understand, and we will understand only what we are taught.” Baba Dioum


  • Dr. P 5 years ago

    This is a practical way to save some bucks for the long run. It also increases the value of the house. Good article.