Suggested R Value For Attic

When determining how much insulation you need don t guesstimate calculate.

Suggested r value for attic.

R value measures how well certain building insulation materials can resist heat. The r value of the insulation for every inch of thickness depends on the type of insulation. Where you live different climates require different insulation r values. The higher the r value the greater the insulation performance.

As a benchmark one inch of solid wood has an r value of 1. See the department of energy s doe ranges for recommended levels of insulation below. The recommended r value for attic insulation in our area of the country minnesota is 49. 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.

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. R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another. 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. 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.

Recommended insulation levels for retrofitting existing wood framed buildings. Existing 3 4 inches of insulation. Blown in cellulose insulation can carry an r value of 3 2 3 8 per inch of thickness. 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.

Add insulation to attic. The amount of insulation recommended for your home will vary depending on a number of factors. To give you a quick example if you blow in 18 of insulation into your attic with an r value of 3 0 per inch you ve got an effective r value of 3 x 18 54. The r value of some insulations also depends on temperature aging and moisture accumulation.

Know exactly how much you need with our project calculators. When calculating the r value of a multilayered installation add the r values of the individual layers. The recommended r value for attic insulation in ontario is between r 50 and r 60.