R Value Of 12 Poured Concrete Wall

Civil engineering and architecture r value and densities chart page 3 the following table was taken from the home energy website.

R value of 12 poured concrete wall.

Cavity wall r values are listed in tek 6 1c r values of multi wythe concrete masonry walls ref. 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. 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. As we said before the r value measures the thermal resistance of a material.

The r values u factors listed in this tek were determined by calculation using the code recognized series parallel also called isothermal planes calculation method refs. Cedar logs and lumber. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. By doubling the thickness of the wall to 16 inches the r value only increases by 0 50.

The reason that it is important to make a good estimate for the current r value for uninsulated spaces is that small changes in r values result in large changes in heat loss when the total r value is low. Concrete block wall with air in cavities r 2 0. R value of 8 20cm concrete block 1 11 r value of 12 30cm concrete block 1 28 r value of 8 20cm poured concrete 0 64 r value of 4 10cm brick 0 80 r value of 1 3cm sheetrock 0 45 r value of 1 3cm sheathing 1 31. 12 two core insulating units concrete.

Total wall assembly r value. 1 25 2 nominal 1 1 2 1 88 2x4 3 1 2 4 38 2x6 5 1 2 6 88. Concrete block 4 inch 0 80 concrete block 8 inch 1 11 concrete block 12 inch 1 28 brick 4 inch common 0 80 brick 4 inch face 0 44 poured concrete 0 08 soft wood lumber 1 25 2 inch nominal 1 inch 1 88 2 x 4 3 inch 4 38 2 x 6 5 inch 6 88 cedar logs and lumber 1 33 sheathing materials plywood 1 25. Concrete block 12 1 28.

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. R values for wall systems no. Brick 4 face. A wall s thermal resistance or its r value is its ability to slow the transfer of heat from one side to the other.

System description clear wall r value rcw whole wall r value rww rww rcw x 100 1.