How Deep Should Attic Insulation Be

The thicker the better.

How deep should attic insulation be.

Inspecting your attic insulation. This allows you to board the attic to use as additional storage space. If your attic insulation is only a few inches thick or if you can see the ceiling joists you re wasting money on your heating and cooling bills. Recommended insulation levels for retrofitting existing wood framed buildings.

Around a 4 inch depth of insulation will be required with the highest performing spray foam. Measure your attic s square footage. The insulation in your attic should be at least 12 thick. The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type.

First things first you need to go up into your attic inspect the condition of the insulation and calculate the current level of 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. 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. For loose fill read labels.

Each bag lists the required depths for a range of r values and the number of bags needed to cover 1 000 square feet at those depths. For loose fill cellulose this translates to a total depth ranging from 8 inches. Fibreglass insulation will need to be laid to a depth of anything between 8 inches and a foot. To insulate to r value 50 with an r value of 3 5 per inch you will need 50 divided by 3 5 or about 14.

Existing 3 4 inches of insulation. It is not uncommon to see 15 to 20 of insulation in a well insulated attic. Add insulation to attic. Calculating thickness divide the desired r value by the r value per inch stated on the label.

Achieving greater r values in attics. The higher the r value the better the thermal performance of the insulation. You can achieve better thermal performance in your attic by adding an.