Attic Ceiling Insulation R Value

See the department of energy s doe ranges for recommended levels of insulation below.

Attic ceiling insulation r value.

You can achieve better thermal performance in your attic by adding an additional layer of insulation. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. Recommended insulation levels for retrofitting existing wood framed buildings. The r value per inch for different types of insulation varies depending on the.

Where you live different climates require different insulation r values. There are many ways to retrofit a home with fiberglass and. While there are additional considerations such as venting and moisture problems to take into account when you insulate under floors the united states department of energy recommends an r 25 rating in cold climates and an r 11 in warmer parts of the country. 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. Add insulation to attic. The 2015 irc requires r 49 insulation for ceilings with attic spaces. 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.

However there is an exception. Achieving greater r values in exterior walls. R 38 shall be deemed to satisfy the requirement for r 49 wherever the full height of uncompressed r 38 insulation extends over the wall top plate at the eaves.