Attic Ceiling Insulation R Value

Where you live different climates require different insulation r values.

Attic ceiling insulation r value.

See the department of energy s doe ranges for recommended levels of insulation below. 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 r value per inch for different types of insulation varies depending on the. Your home s age if your home is more than 10 year old you likely need more insulation.

Add insulation to attic. 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. The 2015 irc requires r 49 insulation for ceilings with attic spaces. The higher the r value the better the thermal performance of the insulation.

However there is an exception. 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. Existing 3 4 inches of insulation. Recommended insulation levels for retrofitting existing wood framed buildings.

You will need a higher r value of insulation if you live in the northeast than if you live in southern california. Achieving greater r values in exterior walls. There are many ways to retrofit a home with fiberglass and.