Adequate Attic Insulation R Value
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.
Adequate attic insulation r value. Add the right kind of insulation. When calculating the r value of a multilayered installation add the r values of the individual layers. According to the u s. Department of energy it s recommended that attics have an r 38 to r 49 or about 12 to 15 of fiberglass or cellulose insulation.
You will need a higher r value of insulation if you live in the northeast than if you live in southern california. The r value depends on the type of insulation its thickness and its density. Achieving greater r values in exterior walls. Existing 3 4 inches of insulation.
Your home s age if your home is more than 10 year old you likely need more insulation. Add insulation to attic. The higher the r value the better the thermal performance of the insulation. R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another.
You can achieve better thermal performance in your attic by adding an additional layer of insulation. The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. But on average a home needs 10 14 inches r 38 of insulation as you can see from this image from energystar go v georgia is a combination of zones 2 3 and 4. As a benchmark one inch of solid wood has an r value of 1.
Warmer climates only require an r 38 or higher or about 12 or more. Fiberglass and cellulose insulation have r values of 2 9 to 3 8 per inch while sprayed foam insulation can go as high as 8 0 per inch. Where you live different climates require different insulation r values. The higher the r value the better the thermal performance of the insulation.
Blown in cellulose insulation can carry an r value of 3 2 3 8 per inch of thickness. R value is a measure of insulation s ability to resist heat flow. Contact coolray online to figure out the exact level of insulation your atlanta area home needs. There are many ways to retrofit a home with fiberglass and.
The r value of some insulations also depends on temperature aging and moisture accumulation. Get an estimate and calculate the payback. Houses in a cold climate should have a minimum of r 49 in the attic which is equivalent to approximately 16 of fiberglass insulation.