Blown In Fiberglass Attic Insulation R Values

Foam in place insulation can be blown into walls on attic surfaces or under floors to insulate and reduce air leakage.
Blown in fiberglass attic insulation r values. 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 along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. Achieving greater r values in exterior walls. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. You can achieve better thermal performance in your attic by adding an additional layer of insulation.
Recommended home insulation r values. R value is a measure of insulation s ability to resist heat traveling through it. This calculator is to be used as an estimating tool only. There are many ways to retrofit a home with fiberglass and.
You can use the small pressurized cans of foam. Click the button to calculate the approximate r value for this job. Your home s age if your home is more than 10 year old you likely need more insulation. As a benchmark one inch of solid wood has an r value of 1.
Input length width and desired r value of the area to be insulated. Input depth of existing blown in insulation in inches. Insulation level are specified by r value. 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.
Fiberglass installation labor cost is about 1 00 to 2 75 per square foot based on the amount of insulation and the location. 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. This calculator is to be used as an estimating tool only. The table below shows what levels of insulation are cost effective for different climates and.
Where you live different climates require different insulation r values. Fiber glass insulation typically contains 20 to 30 recycled glass1. The higher the r value the better the thermal performance of the insulation. The higher the r value the better the thermal performance of the insulation.
The r value of loose fill cellulose is r 3 2 to 3 8 per inch2. Spray foam insulation for both types starts at about 1 50 per square foot and can cost more than 5 00 per square foot when a thick application is applied.