Blown Fiberglass Attic Insulation R Value

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Blown fiberglass attic insulation r value.

Click the button to calculate the depth in inches and pounds of total insulation required for this job. For example a wall with 3 fiberglass batting r value of 10 8. There are many ways to retrofit a home with fiberglass and. This calculator is to be used as an estimating tool only.

You will need a higher r value of insulation if you live in the northeast than if you live in southern california. Where you live different climates require different insulation r values. Click the button to calculate the approximate r value for this job. Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system.

R value is a measure of insulation s ability to resist heat traveling through it. Fiber glass insulation typically contains 20 to 30 recycled glass1. This calculator is to be used as an estimating tool only. Input depth of existing blown in insulation in inches.

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. When blown into attics and wall spaces loose fill fiberglass offers an average r 2 5 thermal value per inch the higher the number the greater the insulating effect. R value measures how well certain building insulation materials can resist heat. Recommended home insulation r values.

Fiberglass insulation is the same type of material that is in batts or rolls of fiberglass insulation except it is chopped or cubed so that it can be installed with an insulation blowing machine. 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. Home improvement stores will often rent you a machine to blow in the fiberglass. Foam in place insulation can be blown into walls on attic surfaces or under floors to insulate and reduce air leakage.

Considering diy blown fiberglass insulation vs spray foam both require care to get the thickness right. Input length width and desired r value of the area to be insulated. The r value of loose fill cellulose is r 3 2 to 3 8 per inch2. When determining how much insulation you need don t guesstimate calculate.

The higher the r value the greater the insulation performance. Spray foam insulation vs fiberglass r value is about equal for open cell insulation and about double for closed cell insulation per one inch layer. The higher the r value the better the thermal performance of the insulation. The table below shows what levels of insulation are cost effective for different climates and.