Blown In Attic Insulation R Value Per Inch

Insulation depth depending on your climate energy codes require varying r values for ceiling insulation.

Blown in attic insulation r value per inch.

The r value of insulation is a measure of how well it reduces the flow of heat and cold into and out of your house. This calculator is to be used as an estimating tool only. 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.

Input length width and desired r value of the area to be insulated. The r value per inch for different types of insulation varies depending on the. The r value of loose fill cellulose is r 3 2 to 3 8 per inch2. Fibers from rock or recycled slag from blast furnaces.

Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. Loose fill fiberglass has an r value of r 2 2 to 2 7 per inch3. The most common blown in material used but it can rot and grow moldy if exposed to moisture. 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.

Fibers from recycled post consumer paper that are treated for insect and fire resistance. You can use the small pressurized cans of foam. The higher the r value per inch of thickness the better job the insulation will do when you heat or cool your home. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation.

While there are additional considerations such as venting and moisture problems to take into account when you insulate under floors the united states department of energy recommends an r 25 rating in cold climates and an r 11 in warmer parts of the country. Where you live different climates require different insulation r values. Click the button to calculate the depth in inches and pounds of total insulation required for this job. As a benchmark one inch of solid wood has an r value of 1.

You will need a higher r value of insulation if you live in the northeast than if you live in southern california. For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed in your attic to reach r 30 if you live in zones 2 or 3. There are many ways to retrofit a home with fiberglass and. 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.

Input depth of existing blown in insulation in inches.