R Rating Insulation Attic

Existing 3 4 inches of insulation.

R rating insulation attic.

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. 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.

Recommended insulation levels for retrofitting existing wood framed buildings. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. Inspecting your attic insulation. 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.

As a benchmark one inch of solid wood has an r value of 1. Warmer climates only require an r 38 or higher or about 12 or more. An insulating material s resistance to conductive heat flow is measured or rated in terms of its thermal resistance or r value the higher the r value the greater the insulating effectiveness. 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.

The r value depends on the type of insulation its thickness and its density. 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. 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. 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.

Let s say the insulation you ve selected has an r value of three per inch and. Add insulation to attic. R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another.