Blown Attic Insulation R Value Per Inch

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Blown attic insulation r value per inch.

By today s standards most homes built more than 10 years ago can be considered under insulated. Input depth of existing blown in insulation in inches. 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. 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.

How much is enough. 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. As a benchmark one inch of solid wood has an r value of 1. This calculator is to be used as an estimating tool only.

You can use the small pressurized cans of foam. 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. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. The r value per inch for different types of insulation varies depending on the.

The higher the r value per inch of thickness the better job the insulation will do when you heat or cool your home. 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.