Desired R Value For Attic

If the insulation is a foam board or sprayed on foam use any visible label information or multiply the thickness in inches by 5 to estimate the r value.

Desired r value for attic. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. Add insulation to attic. Recommended insulation levels for retrofitting existing wood framed buildings. The homeowner could then check table 1 to find several choices.

There are many ways to retrofit a home with fiberglass and. Where you live different climates require different insulation r values. Look at your ductwork. If the existing attic floor insulation has an r 11 insulation value then an additional r 27 would be needed to bring the attic floor insulation up to the level recommended for that house.

Your home s age if your home is more than 10 year old you likely need more insulation. R value insulation chart find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces. Existing 3 4 inches of insulation. It will most likely be a fiberglass batt so multiply the thickness in inches by 3 2 to find out the r value or the r value might be visible on a product label.

For houses in a southwestern state or other areas with generally warmer temperatures you might need attic insulation with an r value of only r 30.