R Value Of Concrete Wall Below Grade

The r value listed by pca for a normal weight 144 pcf 6 inch concrete wall is 1 23 and includes inside and outside air film resistances which contribute to overall thermal resistance.

R value of concrete wall below grade.

The table below shows what levels of insulation are cost effective for different climates and locations in the home. Concrete block wall with perlite in cavities r 2 9. R value is a measure of insulation s ability to resist heat traveling through it. By doubling the thickness of the wall to 16 inches the r value only increases by 0 50.

Ensure minimal long term moisture absorption. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. By comparison most xps warranties typically cover only up to 90 percent of the published r value to account for the r value degradation that occurs in the field. Call pca at 847 966 6200 ext.

In addition the doe recommends r 10 to r 20 insulation for under a slab which we have not taken into consideration for this article. In addition to r value stability rigid foam insulations differ in their rates of moisture absorption and their ability to dry. Above grade concrete wall including inside and outside air films r 1 2 for 6 inch r1 4 for 8 inch. R 0 125 per inch for soil sounds pretty reasonable if we assume about 20 moisture content and if we consider for comparison or a sanity check that the r value of uninsulated concrete is about r 0 8 inch.

The minimum insulation r value recommended by the department of energy for horizontal below grade surfaces in cold climates is r 10 to r 15. For example if you have a type of insulation. Find your zone on the map and then use the above insulation r value chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces. Concrete and block walls.

The higher the r value the better the thermal performance of the insulation. Other engineering sources cite the r value of earth as about r 0 25 per inch or double our calculation. Insulation level are specified by r value.