Finished Attic Insulation R Value

Is this too much for a finished attic.

Finished attic insulation r value.

Existing 3 4 inches of insulation. This means less cold air in the winter and more in the summer. R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another. Houses in a cold climate should have a minimum of r 49 in the attic which is equivalent to approximately 16 of fiberglass insulation.

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. Add insulation to attic. As a benchmark one inch of solid wood has an r value of 1. R value measures how well certain building insulation materials can resist heat.

Your home s age if your home is more than 10 year old you likely need more insulation. Warmer climates only require an r 38 or higher or about 12 or more. Recommended insulation levels for retrofitting existing wood framed buildings. 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.

The higher the r value the greater the insulation performance. 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. I used the r value calculated and it recommended an r value of 49. Where you live different climates require different insulation r values.

There are many ways to retrofit a home with fiberglass and. 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. 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. When determining how much insulation you need don t guesstimate calculate.

None of them have any insulation and it was recommended that it be added by our home inspector. You will need a higher r value of insulation if you live in the northeast than if you live in southern california.