Suggested R Value For Attic

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.

Suggested r value for attic.

You will need a higher r value of insulation if you live in the northeast than if you live in southern california. See the department of energy s doe ranges for recommended levels of insulation below. Existing 3 4 inches of insulation. The r value of the insulation for every inch of thickness depends on the type of insulation.

When determining how much insulation you need don t guesstimate calculate. Installing more insulation in your home increases the r value and the resistance to heat flow. Blown in cellulose insulation can carry an r value of 3 2 3 8 per inch of thickness. 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.

Where you live different climates require different insulation r values. The recommended r value for attic insulation in ontario is between r 50 and r 60. 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. The higher the r value the greater the insulation performance.

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. The recommended r value for attic insulation in our area of the country minnesota is 49. The r value of some insulations also depends on temperature aging and moisture accumulation. Recommended insulation levels for retrofitting existing wood framed buildings.

When calculating the r value of a multilayered installation add the r values of the individual layers. Add insulation to attic. Know exactly how much you need with our project calculators. R value measures how well certain building insulation materials can resist heat.

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. As a benchmark one inch of solid wood has an r value of 1. 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.