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.

R rating insulation attic.

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. First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. Inspecting your attic 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. 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. 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. 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.

Warmer climates only require an r 38 or higher or about 12 or more. Add insulation to 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. As a benchmark one inch of solid wood has an r value of 1.

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. In particularly cold climates you might go up to r 60.

Let s say the insulation you ve selected has an r value of three per inch and. In general an attic s r value should be between r 30 and r 49. 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.