Adding Attic Insulation: Understanding Your Choices

Adding Attic Insulation: Understanding Your Choices

Roll of fiberglass attic insulationThe intense heat of Arizona means your Mesa area home’s energy bills likely skyrocket in the summer. Along with fixing leaking air ducts, one of the best ways to reduce these high cooling bills and save money is by adding attic insulation.

But there are a lot of decisions to be made. This blog will help you understand your attic insulation choices.


When adding insulation to an existing home to reduce air conditioning costs, there are two main types to consider –loose-fill and batt insulation.

  • Loose-fill insulation – Sometimes referred to as blown-in insulation, loose-fill usually offers the easiest installation and more even coverage of the attic floor. The most common materials used in loose-fill insulation are cellulose and fiberglass.
  • Batt (roll) insulation – Batt insulation is currently the most common type of insulation in homes. It comes in rolls (or batts) and is usually made of fiberglass. Mineral wool, plastic fibers and natural fibers (such as cotton and sheep’s wool) can also be found in batts insulation.


The type you select above will most likely determine the material you use for your attic insulation project. But here are some of the most common materials you may run into:

    • Fiberglass – Available in batt and loose-fill forms, fiberglass is one of the most commonly used insulation materials. It consists of extremely fine glass fibers and is available in medium-density and high-density varieties.
  • Cellulose – Cellulose is a type of loose-fill insulation made from recycled wood fibers (like newsprint.) Chemicals are added to the cellulose to make the material insect and fire resistant.
  • Mineral wool – There are two types of mineral wool insulation – rock wool and slag wool. Both are man-made materials with an average of 75% recycled content. The R-value of mineral wool is similar to cellulose and high-density fiberglass.


Regardless of the type and material of attic insulation you choose for your Mesa area home, the R-value is the most important factor. The higher the number, the more efficient the insulation is and the more money you will save on your cooling bills.

For maximum efficiency, ENERGY STAR recommends an attic rated at R60. Since existing homes already have at least 3-4 inches of insulation in the attic, that means adding insulation of about R30-38 (12-15 inches).

Once you have selected the type, material and R-value of your attic insulation, the next step is installation. The U.S. Department of Energy has put together a good guide to attic insulation installation.

Fountain Hills Air provides heating, cooling and air quality services to Mesa and the entire Phoenix metro area.

Sign up for our email newsletter to get more helpful tips as well as exclusive offers.