R Rating For Attic Insulation

The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type.

R rating for attic 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. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. Inspecting your attic insulation. R value is a measure of insulation s ability to resist heat flow.

Recommended insulation levels for retrofitting existing wood framed buildings. In general an attic s r value should be between r 30 and r 49. As a benchmark one inch of solid wood has an r value of 1. R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another.

Existing 3 4 inches of insulation. Add insulation to attic. Warmer climates only require an r 38 or higher or about 12 or more. 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. First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation. Insulation levels are specified by r value. 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.

The higher the r value the better the thermal performance of the insulation. 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. Houses in a cold climate should have a minimum of r 49 in the attic which is equivalent to approximately 16 of fiberglass insulation.