Adequate Attic Insulation R Value

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.

Adequate attic insulation r value.

R value is a measure of insulation s ability to resist heat flow. Contact coolray online to figure out the exact level of insulation your atlanta area home needs. R value is a measure of insulation s ability to resist heat traveling through it. Fiberglass and cellulose insulation have r values of 2 9 to 3 8 per inch while sprayed foam insulation can go as high as 8 0 per inch.

The table below shows what levels of insulation are cost effective for different climates and. The higher the r value the better the thermal performance of the insulation. Recommended home insulation r values. According to the u s.

Note from this chart that the ideal r value differs for each part of your home. Insulation level are specified by r value. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. The higher the r value the better the thermal performance of the insulation.

Get an estimate and calculate the payback. But on average a home needs 10 14 inches r 38 of insulation as you can see from this image from energystar go v georgia is a combination of zones 2 3 and 4. Once you identify the type of insulation you have in a certain location and measure the depth of that insulation in inches you can figure out the total r value of that insulation. R value per inch x number of inches total r value 3 2 x 10 r 32.

R value is simply a material s capacity to resist heat flow. If you are starting off fresh and have no attic insulation as of yet start with an r value of at least 38 you can check local codes and that department of energy chart above for specific recommendations. Where you live different climates require different insulation r values. Insulation is rated by r value.

The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. As a benchmark one inch of solid wood has an r value of 1. 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 along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. 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 in your attic to reach r 30 if you live in zones 2 or 3.

The amount of insulation recommended for your home will vary depending on a number of factors. Insulation levels are specified by r value.