Attic Insulation Thickness R Value

Recommended home insulation r values.

Attic insulation thickness r value. Insulation levels are specified 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. Spray foam pink fiberglas vs. The r value depends on the type of insulation its thickness and its density.

Where you live different climates require different insulation r values. Your home s age if your home is more than 10 year old you likely need more insulation. The higher the r value the better the thermal performance of the insulation. As a benchmark one inch of solid wood has an r value of 1.

Some installations can yield a higher r value than traditional batt insulation for the same thickness and can fill even the smallest cavities creating an effective air barrier. Meaning if you use a tight air seal you don t need to use as high of a total r value. Add the right kind of insulation. The r value of some insulations also depends on temperature aging and moisture accumulation.

Insulation level are specified by r value. R value is a measure of insulation s ability to resist heat traveling through it. 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.

Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. Here s another specific code example. There are many ways to retrofit a home with fiberglass and. Insulation project calculator how to install naima r value certification product training videos colab learning video library for pros distributor locator why owens corning insulation propink vs.

When calculating the r value of a multilayered installation add the r values of the individual layers. Achieving greater r values in exterior walls. 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. You will need a higher r value of insulation if you live in the northeast than if you live in southern california.

You can use the small pressurized cans of foam. For example residential icc code 5 2 9 r806 5 for attic insulation says air impermeable insulation is not required to meet the r value minimum listed in the chart above. See the department of energy s doe ranges for recommended levels of insulation below. 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 additional layer of insulation.