How Many Inches Of Insulation Is Needed In Attic

In temperate coastal areas such as zone 3 attic insulation of at least r30 up to a maximum of r60 is recommended.
How many inches of insulation is needed in attic. For loose fill cellulose this translates to a total depth ranging from 8 inches. In zone 6 the average minimum requirement for attic insulation is 14 inches of r49 fill. In zone 5 the average minimum requirement for attic insulation is 11 inches of r38 fill. The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type.
Inspecting your attic insulation. Click the button to calculate the depth in inches and pounds of total insulation required for this job. It is not uncommon to see 15 to 20 of insulation in a well insulated attic. Once you ve determined the r value of insulation you need to decide which type of insulation you will use.
The thicker the better. The insulation in your attic should be at least 12 thick. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. Find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces.
Depending on type you will need somewhere between 10 and 18 inches of insulation to meet the recommended insulation values. First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation. The average recommended level is 17 inches of r60. The average recommended level is 17 inches of r60.
Add the right kind of insulation when adding additional insulation you do not have to use the same type of insulation that currently exists in your attic. This calculator is to be used as an estimating tool only.