Generally zones 1 and 2 cover the southern states which suggest no necessary values to r 10 for basement walls.
R value concrete wall basement.
The chart you cite is for the above ground framing.
A wall s thermal resistance or its r value is its ability to slow the transfer of heat from one side to the other.
By doubling the thickness of the wall to 16 inches the r value only increases by 0 50.
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 code cited by martin is for basement walls.
Foam insulation is preferred over fiberglass as it has a higher r value is resistant to moisture.
Brian doe s wall foam r value question brian.
The department of energy provides a service to determine the exact r value required based on zip code and type of heating fuel.
You are confusing the minimum thickness of foam on the outside of above ground framing with the code required r value for basement wall insulation using foam.
These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation.
Concrete block makes a cost effective and structurally sound wall but it has.
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.