For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed in your attic to reach r 30 if you live in zones 2 or 3.
Minimum attic insulation r value.
You will need a higher r value of insulation if you live in the northeast than if you live in southern california.
The higher the r value the better the thermal performance of the insulation.
In general to optimally isolate an attic on average an r value of the insulation is required ranging from r 50 to r 60.
Insulation level are specified by r value.
Recommended home insulation r values.
In zone 2 the average minimum requirement for attic insulation is 9 inches of r30 fill.
There are many ways to retrofit a home with fiberglass and.
Warmer climates only require an r 38 or higher or about 12 or more.
How much insulation in attic for zones 1 4.
The table below shows what levels of insulation are cost effective for different climates and.
R value is a measure of insulation s ability to resist heat traveling through it.
The insulation levels of an attic or of any part of a house are understood through the r value that is the value with which the insulating material is resistant to heat flow.
The average recommended level is 17 inches of r60.
In zone 1 the average minimum requirement for attic insulation is 9 inches of r30 fill.
Houses in a cold climate should have a minimum of r 49 in the attic which is equivalent to approximately 16 of fiberglass insulation.