Attic Insulation Thickness R Value

The table below shows what levels of insulation are cost effective for different climates and.

Attic insulation thickness r value.

The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. Recommended home insulation r values. Insulation levels are specified by r value. Add the right kind of insulation.

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. R value is a measure of insulation s ability to resist heat traveling through it. The r value depends on the type of insulation its thickness and its density. 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.

Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces. The higher the r value the better the thermal performance of the insulation. 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. You can use the small pressurized cans of foam.

When calculating the r value of a multilayered installation add the r values of the individual layers. The r value of some insulations also depends on temperature aging and moisture accumulation. Here s another specific code example. 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. Your home s age if your home is more than 10 year old you likely need more insulation. Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. You will need a higher r value of insulation if you live in the northeast than if you live in southern california.

See the department of energy s doe ranges for recommended levels of insulation below. R value is a measure of insulation s ability to resist heat flow. Insulation level are specified by r value. 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. Spray foam pink fiberglas vs. Foam in place insulation can be blown into walls on attic surfaces or under floors to insulate and reduce air leakage. Meaning if you use a tight air seal you don t need to use as high of a total r value.

Achieving greater r values in exterior walls.