The Typical Depth of Insulation for the Attic of a House

Identification

• Examine your attic to determine if you have the right amount of insulation in the correct areas. According to the Environmental Protection Agency, the insulation in your attic should be well above the joists in the floor. If your insulation is not deep enough to cover your floor joists, you should add more insulation. For maximum benefits, your attic insulation must extend all the way out to your eaves and should be distributed evenly throughout your attic.

Types

• Adding the right kind of insulation to your attic is as important as having adequate coverage. You can add a different type of insulation to your attic than you currently have. In new construction, you have several different types of insulation to choose from. Blanket insulation is also known as batt and roll insulation and is the most common type of insulation used in attics. This type of insulation usually comes in big rolls and is typically made from fiberglass. Loose-fill insulation is another type of insulation and is blown into the attic with a special machine. No matter which type you choose, make sure you place the proper amount in your attic and spread it evenly throughout.

R-Value

• The R-value of your insulation determines how well it will insulate your attic. R-values are the way manufacturers grade their insulation's ability to resist heat flow. Choosing an insulation with a high R-value, will ensure the best performance. According to the EPA, homeowners should choose an insulation that has an R-38 value and has a thickness of 10 to 14 inches.

Considerations

• Insulation works best in your attic if all air leaks are sealed. Before installing or adding additional insulation inside your attic, look around for any gaps that may allow air to escape or enter your attic. Seal any small to medium sized gaps with caulk or use rigid foam board insulation to seal larger holes. Areas around attic hatches and attic ceilings frequently have gaps that require sealing. Avoid covering your soffit vents when installing insulation, as this interferes with attic ventilation.