Attic Insulation R Value Code

Energy star states that an r 60 is equal to the best performing attic insulation.

Attic insulation r value code.

Recommended home insulation r values. 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. 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. Insulation level are specified by r value.

You will need a higher r value of insulation if you live in the northeast than if you live in southern california. You can achieve better thermal performance in your attic by adding an additional layer of insulation. R value is a measure of insulation s ability to resist heat traveling through it. 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. 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. 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. 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. However if an r 38 was enough customers wouldn t ask why they re still too cold or hot in their home. 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. 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.

Where using a simulated energy performance analysis sections of ducts that are installed in accordance with section 1103 3 6 located directly on or within 5 5 inches 140 mm of the ceiling surrounded with blown in attic insulation having an r value of r 30 or greater and located such that the top of the duct is not less than 3 5 inches 89. 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. 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.

The higher the r value the better the thermal performance of the insulation. For an attic the you could have an r 38 to meet the insulation code guidelines. The table below shows what levels of insulation are cost effective for different climates and.