Click the button to calculate the approximate r value for this job.
How many inches of insulation attic.
In temperate coastal areas such as zone 3 attic insulation of at least r30 up to a maximum of r60 is recommended.
Once you ve determined the r value of insulation you need to decide which type of insulation you will use.
Input length width and desired r value of the area to be insulated.
Fiberglass and cellulose insulation have r values of 2 9 to 3 8 per inch while sprayed foam insulation can go as high as 8 0 per inch.
Click the button to calculate the depth in inches and pounds of total insulation required for this job.
Input depth of existing blown in insulation in inches.
Note from this chart that the ideal r value differs for each part of your home.
The average recommended level is 17 inches of r60.
In zone 4 the average minimum requirement for attic insulation is 11 inches of r38 fill.
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.
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.
Inspecting your attic insulation.
Input length width and desired r value of the area to be insulated.
In zone 3 the average minimum requirement for attic insulation is 9 inches of r30 fill.
First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation.
Department of energy it s recommended that attics have an r 38 to r 49 or about 12 to 15 of fiberglass or cellulose insulation.
The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type.
For loose fill cellulose this translates to a total depth ranging from 8 inches.
This calculator is to be used as an estimating tool only.
According to the u s.
Depending on type you will need somewhere between 10 and 18 inches of insulation to meet the recommended insulation values.