R Rating Insulation Attic

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

R rating insulation 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. Warmer climates only require an r 38 or higher or about 12 or more. 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. First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation.

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. 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 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. 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.

Existing 3 4 inches of insulation. Let s say the insulation you ve selected has an r value of three per inch and. 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. As a benchmark one inch of solid wood has an r value of 1.

Inspecting your attic insulation. Add insulation to attic. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. In particularly cold climates you might go up to r 60.

In general an attic s r value should be between r 30 and r 49. Recommended insulation levels for retrofitting existing wood framed buildings. See the department of energy s doe ranges for recommended levels of insulation below.