Blown Fiberglass Attic Insulation R Value

When determining how much insulation you need don t guesstimate calculate.

Blown fiberglass attic insulation r value.

Fiber glass insulation typically contains 20 to 30 recycled glass1. Home improvement stores will often rent you a machine to blow in the fiberglass. The r value of loose fill cellulose is r 3 2 to 3 8 per inch2. Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system.

Your home s age if your home is more than 10 year old you likely need more insulation. 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. Where you live different climates require different insulation r values. Considering diy blown fiberglass insulation vs spray foam both require care to get the thickness right.

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 is a measure of insulation s ability to resist heat traveling through it. 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. Click the button to calculate the depth in inches and pounds of total insulation required for this job.

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. 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. The table below shows what levels of insulation are cost effective for different climates and. Input length width and desired r value of the area to be insulated.

Input depth of existing blown in insulation in inches. The higher the r value the greater the insulation performance. Click the button to calculate the approximate r value for this job. Foam in place insulation can be blown into walls on attic surfaces or under floors to insulate and reduce air leakage.

Insulation level are specified by r value. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. You can use the small pressurized cans of foam. For example a wall with 3 fiberglass batting r value of 10 8.

Know exactly how much you need with our project calculators. This calculator is to be used as an estimating tool only. This calculator is to be used as an estimating tool only. R value measures how well certain building insulation materials can resist heat.