Attic Insulation R Value Depth

The r value of loose fill cellulose is r 3 2 to 3 8 per inch2.

Attic insulation r value depth.

But newer homes in central and southern arizona are insulated to ratings of r 30 to r 38 while newer homes in northern arizona generally have attic insulation at r 60 because of colder winters. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. Input depth of existing blown in insulation in inches.

For loose fill cellulose this translates to a total depth ranging from 8 inches. You can achieve better thermal performance in your attic by adding an additional layer of insulation. Click the button to calculate the approximate r value for this job. Loose fill fiberglass has an r value of r 2 2 to 2 7 per inch3.

Add the right kind of insulation. As a benchmark one inch of solid wood has an r value of 1. Achieving greater r values in exterior walls. Your home s age if your home is more than 10 year old you likely need more insulation.

To get the target r value from the product you chose use the number of bags your calculations showed that you needed to insulate your attic never fewer. In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7. There are many ways to retrofit a home with fiberglass and. Add insulation to attic.

Achieving the desired r value depends on both the depth of the insulation and its density. R value is a measure of insulation s ability to resist heat flow. Recommended insulation levels for retrofitting existing wood framed buildings. If you ve reached your target depth but still have a few bags left over keep adding the material at an even depth throughout the space until all the bags your calculations called for are empty.

The higher the r value the better the thermal performance of the insulation. Insulation depth depending on your climate energy codes require varying r values for ceiling insulation. Existing 3 4 inches of insulation. This calculator is to be used as an estimating tool only.

Where you live different climates require different insulation r values.