R Rating Insulation In Attic

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.

R rating insulation in attic.

Insulation levels are specified by r value. As a benchmark one inch of solid wood has an r value of 1. 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. R value is a measure of insulation s ability to resist heat flow.

In particularly cold climates you might go up to r 60. The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. In general an attic s r value should be between r 30 and r 49. Existing 3 4 inches of insulation.

R value insulation chart find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces. See the department of energy s doe ranges for recommended levels of insulation below. Houses in a cold climate should have a minimum of r 49 in the attic which is equivalent to approximately 16 of fiberglass insulation. Let s say the insulation you ve selected has an r value of three per inch and.

Warmer climates only require an r 38 or higher or about 12 or more. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. 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. 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 higher the r value the better the thermal performance of the insulation. 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. Recommended insulation levels for retrofitting existing wood framed buildings.

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