Reference table for u values u value is the coefficient of transmission i e the transmission of heat through the materials which compose the building s envelope or outer shell.
R value of poured concrete walls.
I agree mostly with junio s answer.
U value has an inverse relationship to r value.
A wall s thermal resistance or its r value is its ability to slow the transfer of heat from one side to the other.
Icf foundations have an r value of greater than 20.
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.
Cedar logs and lumber.
For example a building with material with an r value of r 11 converts to an u value of 0 09 1 r or 1 11 0 09.
Wood frame walls 3 plus r value of the insulation used floors above unheated spaces 2 plus r value of the insulation used.
However too many people confuse insulation properties with thermal mass many icf dealers d.
But concrete is a conductor of thermal energy not an insulator.
To obtain a wall or ceiling assembly r value you must add the r values of the individual components together.
By doubling the thickness of the wall to 16 inches the r value only increases by 0 50.
Poured concrete foundations have r values of less than 3.
As we said before the r value measures the thermal resistance of a material.
Therefore technically it has no insulation value.
Poured concrete walls can leak moisture through non structural cracks in the wall where the floor and wall meet at the top of the foundation wall or through the porous concrete.
Use the r value table below to help you determine the r value of your wall or ceiling assemblies.
1 25 2 nominal 1 1 2 1 88 2x4 3 1 2 4 38 2x6 5 1 2 6 88.
For instance if you have a material with an r value of 12 attached to another material with an r value of 3 then both materials combined have an r value of 15.