How Deep Should Attic Insulation Be

Recommended insulation levels for retrofitting existing wood framed buildings.
How deep should attic insulation be. Calculating thickness divide the desired r value by the r value per inch stated on the label. 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. The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. Around a 4 inch depth of insulation will be required with the highest performing spray foam.
In temperate coastal areas such as zone 3 attic insulation of at least r30 up to a maximum of r60 is recommended. Inspecting your attic insulation. Measure your attic s square footage. This allows you to board the attic to use as additional storage space.
Existing 3 4 inches of insulation. Add insulation to attic. For loose fill cellulose this translates to a total depth ranging from 8 inches. Each bag lists the required depths for a range of r values and the number of bags needed to cover 1 000 square feet at those depths.
The insulation in your attic should be at least 12 thick. If your attic insulation is only a few inches thick or if you can see the ceiling joists you re wasting money on your heating and cooling bills. First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of 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.
To insulate to r value 50 with an r value of 3 5 per inch you will need 50 divided by 3 5 or about 14. The higher the r value the better the thermal performance of the insulation. 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. The thicker the better.
You can achieve better thermal performance in your attic by adding an. For loose fill read labels. Achieving greater r values in attics.