Concrete block walls u values r values.
R value of 8 concrete wall.
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.
A wall s thermal resistance or its r value is its ability to slow the transfer of heat from one side to the other.
As we said before the r value measures the thermal resistance of a material.
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.
Typical residential weight concrete 8 wall r 2 5.
Block thickness in inches.
Concrete sand gravel aggregate.
Concrete block makes a cost effective and structurally sound wall but it has.
The insulation may be poured directly into walls or emptied into a simply wood or metal hopper which can be slid along the wall to direct the free flowing perlite into cores of cavities thus insulating all voids and air pockets.
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.
Concrete block wall with perlite in cavities r 2 9.
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.
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.
R values for concrete masonry walls exposed both sides density r value increase problock 85 pcf 10 69 226 problock 105 pcf 8 27 152 traditional 3 web nw cmu 130 pcf 3 28 0 problock 85 pcf 18 14 264 problock 105 pcf 13 94 179 traditional 3 web nw cmu 130 pcf 4 99 0.
R inch r thick ness insulation materials fiberglass batt 3 14 fiberglass blown attic 2 20 1 fiberglass blown wall 3 20 rock wool batt 3 14 rock wool blown attic 3 10 rock wool blown wall 3 03 cellulose blown attic 3 13 cellulose blown wall 3 70 vermiculite 2 13 air entrained concrete 3 90 urea terpolymer foam 4 48.
For example if you miss the r.
Cavity wall r values are listed in tek 6 1c r values of multi wythe concrete masonry walls ref.
8 thick concrete slab or foundation wall has an r value of about 1 04 30 while lightweight aggregate filled 8 thick concrete has an r value of about 2 18 30.
Concrete block wall with air in cavities r 2 0.