How Many Inches Of Insulation Should Be In My Attic

Use unfaced insulation when adding more insulation to an attic that already has some insulation laying the rolls or batts at right angles to the floor joists.
How many inches of insulation should be in my attic. First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of insulation. According to the u s. Inspecting your attic insulation. 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.
The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. 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. In temperate coastal areas such as zone 3 attic insulation of at least r30 up to a maximum of r60 is recommended. The thicker the better.
Department of energy it s recommended that attics have an r 38 to r 49 or about 12 to 15 of fiberglass or cellulose insulation. You ll need about 12 inches of insulation material. Here are the most popular options for attic insulation along with a ballpark figure on pricing. Depending on type you will need somewhere between 10 and 18 inches of insulation to meet the recommended insulation values.
Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. 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. Recommended insulation levels for retrofitting existing wood framed buildings. 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.
For loose fill cellulose this translates to a total depth ranging from 8 inches. Existing 3 4 inches of insulation. They come with or without a paper or foil facing that acts as a vapor barrier. It is not uncommon to see 15 to 20 of insulation in a well insulated attic.
Once you ve determined the r value of insulation you need to decide which type of insulation you will use.