Attic Insulation R Value Inches

Your home s age if your home is more than 10 year old you likely need more insulation.

Attic insulation r value inches.

Know exactly how much you need with our project calculators. There are many ways to retrofit a home with fiberglass and. When determining how much insulation you need don t guesstimate calculate. This calculator is to be used as an estimating tool only.

Insulation levels are specified by r value. Where you live different climates require different insulation r values. The total r value of installed insulation is calculated by multiplying its baseline r value times the depth of the insulation in inches. In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7.

The r value of insulation is a measure of how well it reduces the flow of heat and cold into and out of your house. Lighter in weight than cellulose or mineral wool but it settles more than those materials so you ve got to put in a thicker layer to get the protection you need. R value is a measure of insulation s ability to resist heat traveling through it. You will need a higher r value of insulation if you live in the northeast than if you live in southern california.

Input depth of existing blown in insulation in inches. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. The higher the r value the better the thermal performance of the insulation. Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system.

Insulation level are specified by r value. The table below shows what levels of insulation are cost effective for different climates and. Add the right kind of insulation. The higher the r value the greater the insulation performance.

For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed your attic to reach r 30 if you live in zones 2 or 3. The higher the r value per inch of thickness the better job the insulation will do when you heat or cool your home. Recommended home insulation r values. Click the button to calculate the approximate r value for this job.

The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. Recycled glass or sand that s melted and spun into fibers. R value is a measure of insulation s ability to resist heat flow. As a benchmark one inch of solid wood has an r value of 1.