R Rating Insulation In Attic

Recommended insulation levels for retrofitting existing wood framed buildings.

R rating insulation in attic.

Houses in a cold climate should have a minimum of r 49 in the attic which is equivalent to approximately 16 of fiberglass insulation. Inspecting your attic insulation. 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. Existing 3 4 inches of insulation.

Warmer climates only require an r 38 or higher or about 12 or more. R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another. 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. First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation.

In particularly cold climates you might go up to r 60. 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. The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. See the department of energy s doe ranges for recommended levels of insulation below.

As a benchmark one inch of solid wood has an r value of 1. In general an attic s r value should be between r 30 and r 49. R value is a measure of insulation s ability to resist heat flow. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.

Your attic should have a certain amount of insulation in it and the recommended level of insulation for your attic is dependent on where you live. Let s say the insulation you ve selected has an r value of three per inch and. 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 r value for cellulose insulation in an attic depends on several factors including the size shape and construction of your attic typical weather conditions where you live any air leaks and.

The higher the r value the better the thermal performance of the insulation.