Minimum Insulation Thickness In Attic

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.

Minimum insulation thickness in attic.

For loose fill cellulose this translates to a total depth ranging from 8 inches. The homeowner could then check table 1 to find several choices. The recommended r value for attic floor insulation for this house is r 38. Residents of southern and central texas should insulate their attics to at least r 30 or about 9 5 inches of conventional fiberglass batt insulation.

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 to maintain a consistent total sheathing thickness. Add the right kind of insulation when adding additional insulation you do not have to use the same type of insulation that currently exists in your attic. 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. Uninsulated attic spaces are responsible for significant heat loss since heat rises in a building.

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. Add insulation to attic. In temperate coastal areas such as zone 3 attic insulation of at least r30 up to a maximum of r60 is recommended. This flexible insulation material is most often packaged in rolls that come in various thicknesses and standard widths usually 16 inches and 24 inches to fit between joists or studs in a house s framing.

The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. Recommended insulation levels for retrofitting existing wood framed buildings. In zone 4 the average minimum requirement for attic insulation is 11 inches of r38 fill. They come with or without a paper or foil facing that acts as a vapor barrier.

Inspecting your attic insulation. In zone 3 the average minimum requirement for attic insulation is 9 inches of r30 fill. If you live in the texas panhandle consider increasing your insulation level to at least r 38. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.

Your attic should have a certain amount of insulation in it and the recommended level of insulation for your attic is dependent on where you live.