Suggested R Value For Attic

The higher the r value the greater the insulation performance.

Suggested r value for attic.

Recommended insulation levels for retrofitting existing wood framed buildings. R value measures how well certain building insulation materials can resist heat. The amount of insulation recommended for your home will vary depending on a number of factors. Depending on where you live and the part of your home you re insulating walls crawlspace attic etc you ll need a different 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. R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another. Where you live different climates require different insulation r values. Installing more insulation in your home increases the r value and the resistance to heat flow.

When determining how much insulation you need don t guesstimate calculate. The recommended r value for attic insulation in our area of the country minnesota is 49. See the department of energy s doe ranges for recommended levels of insulation below. R values of common types of insulation the two distinct types of attic insulation are loose fill material also commonly known as blown in insulation and batting.

Add insulation to attic. Know exactly how much you need with our project calculators. As a benchmark one inch of solid wood has an r value of 1. But newer homes in central and southern arizona are insulated to ratings of r 30 to r 38 while newer homes in northern arizona generally have attic insulation at r 60 because of colder winters.

Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces. Existing 3 4 inches of insulation. The r value of the insulation for every inch of thickness depends on the type of insulation. The r value of some insulations also depends on temperature aging and moisture accumulation.

Blown in cellulose insulation can carry an r value of 3 2 3 8 per inch of thickness. While some ceilings in the southwestern part of the united states require a minimum of r 19 insulation most attics or ceiling areas require a minimum of r 38 in the ceiling. When calculating the r value of a multilayered installation add the r values of the individual layers.