Insulation Rating For 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.
Insulation rating for attic. Warmer climates only require an r 38 or higher or about 12 or more. 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 along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. 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. See the department of energy s doe ranges for recommended levels of insulation below.
Existing 3 4 inches of insulation. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. Add insulation to attic. 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.