Fiberglass Attic Insulation R Value

It can be located on a card left by the previous installer printed on the attic insulation or you can measure it yourself.

Fiberglass attic insulation r value.

The loss of r value started at a temperature difference of about 32 f. The higher the r value the better the thermal performance of the insulation. The loose fill fiberglass showed a significant reduction in r value as the attic got colder and the temperature difference got larger. You can achieve better thermal performance in your attic by adding an additional layer of insulation.

As you can see there s some variation in r value depending on the particular type and brand of products used. Warmer climates only require an r 38 or higher or about 12 or more. Recommended home insulation r values. The higher the r value the better the thermal performance of the insulation.

Houses in a cold climate should have a minimum of r 49 in the attic which is equivalent to approximately 16 of fiberglass insulation. Achieving greater r values in exterior walls. Insulation level are specified by r value. Input depth of existing blown in insulation in inches.

Depending on where you live it s recommended that attics have a minimum r value of r 30 in warm climates to r 60 in cold climates. Click the button to calculate the approximate r value for this job. First you ll need to determine your r value. 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. 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. R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another. As a benchmark one inch of solid wood has an r value of 1.

If it s a new building simply reference the energy code map.