A wall s thermal resistance or its r value is its ability to slow the transfer of heat from one side to the other.
													
																	R value of 8 concrete wall. 
									
	
		
	
																	Concrete block makes a cost effective and structurally sound wall but it has. 
																	By doubling the thickness of the wall to 16 inches the r value only increases by 0 50. 
																	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. 
																	Block thickness in inches. 
															
													
									
	
		
	
																	Concrete block walls u values r values. 
																	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. 
																	Typical residential weight concrete 8 wall r 2 5. 
																	These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. 
															
													
									
	
		
	
																	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. 
																	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 sand gravel aggregate. 
																	For example if you miss the r. 
															
													
									
	
		
	
																	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. 
																	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. 
																	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. 
																	As we said before the r value measures the thermal resistance of a material. 
																	Concrete block wall with air in cavities r 2 0. 
																	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.