Attic Insulation R Value Depth

The higher the r value the better the thermal performance of the insulation.

Attic insulation r value depth.

Insulation depth depending on your climate energy codes require varying r values for ceiling insulation. For loose fill cellulose this translates to a total depth ranging from 8 inches. 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. R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another.

Achieving greater r values in exterior walls. 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. 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. The r value of loose fill cellulose is r 3 2 to 3 8 per inch2.

Add the right kind of insulation. Click the button to calculate the approximate r value for this job. Existing 3 4 inches of insulation. You will need a higher r value of insulation if you live in the northeast than if you live in southern california.

The higher the r value the better the thermal performance of the insulation. Recommended insulation levels for retrofitting existing wood framed buildings. R value is a measure of insulation s ability to resist heat flow. There are many ways to retrofit a home with fiberglass and.

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. As a benchmark one inch of solid wood has an r value of 1. Input depth of existing blown in insulation in inches. Where you live different climates require different insulation r values.

This calculator is to be used as an estimating tool only. Loose fill fiberglass has an r value of r 2 2 to 2 7 per inch3. In temperate coastal areas such as zone 3 attic insulation of at least r30 up to a maximum of r60 is recommended. Your home s age if your home is more than 10 year old you likely need more insulation.

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