Finished Attic Insulation R Value

I used the r value calculated and it recommended an r value of 49.

Finished attic insulation r value. Houses in a cold climate should have a minimum of r 49 in the attic which is equivalent to approximately 16 of fiberglass insulation. Adding multiple layers of insulation doesn t increase the r value because it is measured in conducted heat ventilation is very important when you insulate your. When determining how much insulation you need don t guesstimate calculate. There are many ways to retrofit a home with fiberglass and.

You will need a higher r value of insulation if you live in the northeast than if you live in southern california. R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another. The r value represent the temperature resistance of the insulation material meaning the ability to stop heat transfer. Add insulation to attic.

Where you live different climates require different insulation r values. To find the r value of the existing insulation in your attic multiply the number of inches of insulation by the r value for your particular type. Recommended insulation levels for retrofitting existing wood framed buildings. Warmer climates only require an r 38 or higher or about 12 or more.

Existing 3 4 inches of 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. Your home s age if your home is more than 10 year old you likely need more insulation. This means less cold air in the winter and more in the summer.

For example if your home has cellulose insulation at a depth of 8 inches between the joists the attic insulation has an r value of 3 7 times 8 or 29 6. The higher the r value the greater the insulation performance. Finishing an attic with trusses if your roof is supported by trusses you will probably not have the space in your attic to build a room. As a benchmark one inch of solid wood has an r value of 1.

None of them have any insulation and it was recommended that it be added by our home inspector. R value measures how well certain building insulation materials can resist heat.