Blown In Attic Insulation R Value Per Inch

Input length width and desired r value of the area to be insulated.

Blown in attic insulation r value per inch.

As a benchmark one inch of solid wood has an r value of 1. The most common blown in material used but it can rot and grow moldy if exposed to moisture. While there are additional considerations such as venting and moisture problems to take into account when you insulate under floors the united states department of energy recommends an r 25 rating in cold climates and an r 11 in warmer parts of the country. Some installations can yield a higher r value than traditional batt insulation for the same thickness and can fill even the smallest cavities creating an effective air barrier.

There are many ways to retrofit a home with fiberglass and. Loose fill fiberglass has an r value of r 2 2 to 2 7 per inch3. Achieving the desired r value depends on both the depth of the insulation and its density. Insulation depth depending on your climate energy codes require varying r values for ceiling insulation.

This calculator is to be used as an estimating tool only. This calculator is to be used as an estimating tool only. The r value per inch for different types of insulation varies depending on the. 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.

These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. You can use the small pressurized cans of foam. Click the button to calculate the approximate r value for this job. The r value of insulation is a measure of how well it reduces the flow of heat and cold into and out of your house.

Fibers from rock or recycled slag from blast furnaces. Foam in place insulation can be blown into walls on attic surfaces or under floors to insulate and reduce air leakage. Fibers from recycled post consumer paper that are treated for insect and fire resistance. The higher the r value per inch of thickness the better job the insulation will do when you heat or cool your home.

Input depth of existing blown in insulation in inches. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. Click the button to calculate the depth in inches and pounds of total insulation required for this job. The r value of loose fill cellulose is r 3 2 to 3 8 per inch2.

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.