R Value Of Concrete Wall Below Grade

In addition to r value stability rigid foam insulations differ in their rates of moisture absorption and their ability to dry.

R value of concrete wall below grade.

Depending on the density of the blocks an 8 inch thick block wall without any other type of. Ensure minimal long term moisture absorption. 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. Concrete block makes a cost effective and structurally sound wall but it has little thermal resistance.

564 to obtain copies of this reference. And sheath it with 1 3cm sheets of thermax and 1 3cm sheetrock the total r value would be 14 75. Concrete block wall with perlite in cavities r 2 9. 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.

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 r value of an uninsulated 8 inch thick basement wall built using normal weight concrete is 1 35 based on data from the 1993 american society of heating refrigeration and air conditioning engineers handbook. Other engineering sources cite the r value of earth as about r 0 25 per inch or double our calculation. 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.

If you are building your house you have the advantage of being able to insulate properly right from the. Call pca at 847 966 6200 ext.