Acceptable Attic Insulation R Value

Recommended home insulation r values.

Acceptable attic insulation r value.

Insulation level are specified by r value. The table below shows what levels of insulation are cost effective for different climates and. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. However there is an exception.

Each state does have their own minimum insulation requirements which are often lower than the levels recommended by the department of energy. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. The 2015 irc requires r 49 insulation for ceilings with attic spaces. Your home s age if your home is more than 10 year old you likely need more insulation.

Where you live different climates require different insulation r values. This zone has a recommended r value of 30 to 60 for an uninsulated attic r25 to r38 for an attic with existing insulation and r13 to r19 for the floor. There are many ways to retrofit a home with fiberglass and. 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.

See the department of energy s doe ranges for recommended levels of insulation below. Pa302 1 ceilings with attic spaces n1102 2 1 r402 2 1. Often the depth of the wood shaving insulation was insufficient to today s standards and as it settled it has little or no thermal benefits. 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.

If you are heating a home with wood chips in the attic then you are wasting. R value is a measure of insulation s ability to resist heat traveling through it. The higher the r value the better the thermal performance of the insulation. Typical fiberglass batt insulation has an r value between 2 9 and 3 8 per inch of thickness.