Attic Insulation R Value Code

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.

Attic insulation r value code.

For an attic the you could have an r 38 to meet the insulation code guidelines. 2015 code requires walls to be insulated with a minimum of r 20 or r 13 5 13 5 means r 13 cavity insulation plus r 5 insulated sheathing. However if an r 38 was enough customers wouldn t ask why they re still too cold or hot in their home. Where you live different climates require different insulation r values.

The higher the r value the better the thermal performance of the insulation. There are many ways to retrofit a home with fiberglass and. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. Dte energy and consumers energy suggest an r 49 or above to be energy efficient.

Insulation level are specified by r value. The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process. Recommended home insulation r values. If structural sheathing covers 40 or less of the exterior continuous insulation r value shall be permitted to be reduced by no more than r 3 in the locations where structural sheathing is used.

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. R value is a measure of insulation s ability to resist heat traveling through it. In general to optimally isolate an attic on average an r value of the insulation is required ranging from r 50 to r 60. Achieving greater r values in exterior walls.

The table below shows what levels of insulation are cost effective for different climates and. The international codes i codes are the widely accepted comprehensive set of model codes used in the us and abroad to help ensure the engineering of safe sustainable affordable and resilient structures. Your home s age if your home is more than 10 year old you likely need more insulation. You can achieve better thermal performance in your attic by adding an additional layer of 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. 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 your attic to reach r 30 if you live in zones 2 or 3. You will need a higher r value of insulation if you live in the northeast than if you live in southern california.