How Many Inches Of Insulation Does An Attic Need

The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type.

How many inches of insulation does an attic need.

Having enough insulation in your attic is one of the best ways to save energy on both heating and cooling your home. Most batt insulation carries an r value of 2 9 to 3 8 per inch. The average recommended level is 17 inches of r60. Your attic should have a certain amount of insulation in it and the recommended level of insulation for your attic is dependent on where you live.

For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed in your attic to reach r 30 if you live in zones 2 or 3. In temperate coastal areas such as zone 3 attic insulation of at least r30 up to a maximum of r60 is recommended. Therefore a 3 1 2 inch wall cavity filled with fiberglass batts has an r value of 10 15 to 13 3. How well a particular insulation works is expressed by the r value which ranges from 2 0 to 8 0 per inch of insulation.

The higher the r value the better job the insulation does at preventing the transfer of heat. Input length width and desired r value of the area to be insulated. Click the button to calculate the depth in inches and pounds of total insulation required for this job. For loose fill cellulose this translates to a total depth ranging from 8 inches.

First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. Input length width and desired r value of the area to be insulated. Depending on type you will need somewhere between 10 and 18 inches of insulation to meet the recommended insulation values.

How much insulation in attic for zones 1 4. In zone 1 the average minimum requirement for attic insulation is 9 inches of r30 fill. In zone 2 the average minimum requirement for attic insulation is 9 inches of r30 fill. Previous post next post call us today at 888 468 0700.

This calculator is to be used as an estimating tool only. When adding additional insulation you do not have to use the same type of insulation that currently exists in your. Add the right kind of insulation. Click the button to calculate the depth in inches and pounds of total insulation required for this job.

Inspecting your attic insulation. Fiberglass and rock wool batts are probably the most popular options and are easy to install in unfinished walls and attics.