Attic Insulation Levels

Existing 3 4 inches of insulation.

Attic insulation levels.

For batts or rolls calculate the number based on the width and length of the product you re using. R value is a measure of insulation s ability to resist heat flow. Either read the r value printed on the batts of your existing insulation or use a measuring tape ruler to measure the depth of the insulation inches. Recommended insulation levels for retrofitting existing wood framed buildings.

In most cases the best type of attic insulation will be blown fiberglass or blown cellulose insulation. The depth varies quite a bit because we have attic trusses and a floor in the attic. Our attic has between 12 inches and 16 inches of cellulose insulation. Looking across your attic if the insulation is level with or below the attic floor joists you probably need to add more insulation.

Add insulation to attic. The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. So we have between r36 and r56 in the attic. Measure your attic s square footage.

For uninsulated attics for attics with existing 3 4 inches of insulation for uninsulated basements or crawlspaces. Cellulose insulation has an r value of approximately 3 to 3 5 per inch. Existing 3 4 inches of insulation. For loose fill read labels.

Add the right kind of insulation. The higher the r value the better the thermal performance of the insulation. When adding additional insulation you do not have to use the same type of insulation that currently exists in your attic. 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.

Add the following insulation levels to your attic floor. You will want to record your measurement so you can determine how much more insulation you need to achieve the recommended levels. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. Where we re lacking a bit is in the 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. The levels of attic insulation recommended today by energy star are substantially higher than those used earlier so it s worth checking out what s recommended in your geographic area. Insulation levels are specified by r value.