In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7.
													
																	Attic insulation r value inches. 
									
	
		
	
																	The r value of insulation is a measure of how well it reduces the flow of heat and cold into and out of your house. 
																	As a benchmark one inch of solid wood has an r value of 1. 
																	R value is a measure of insulation s ability to resist heat traveling through it. 
																	When determining how much insulation you need don t guesstimate calculate. 
															
													
									
	
		
	
																	Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. 
																	Input depth of existing blown in insulation in inches. 
																	Cellulose insulation has a baseline r value of 3 8 per inch. 
																	Click the button to calculate the approximate r value for this job. 
															
													
									
	
		
	
																	The higher the r value the greater the insulation performance. 
																	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 your attic to reach r 30 if you live in zones 2 or 3. 
																	The total r value of installed insulation is calculated by multiplying its baseline r value times the depth of the insulation in inches. 
																	The table below shows what levels of insulation are cost effective for different climates and. 
															
													
									
	
		
	
																	You will need a higher r value of insulation if you live in the northeast than if you live in southern california. 
																	R value is a measure of insulation s ability to resist heat flow. 
																	The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. 
																	These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. 
															
													
									
	
		
	
																	The higher the r value per inch of thickness the better job the insulation will do when you heat or cool your home. 
																	The higher the r value the better the thermal performance of the insulation. 
																	Your home s age if your home is more than 10 year old you likely need more insulation. 
																	Recycled glass or sand that s melted and spun into fibers. 
															
													
									
	
		
	
																	Where you live different climates require different insulation r values. 
																	The higher the r value the better the thermal performance of the insulation. 
																	Know exactly how much you need with our project calculators. 
																	Recommended home insulation r values. 
															
													
									
	
		
	
																	Insulation level are specified by r value. 
																	Insulation levels are specified by r value. 
																	Add the right kind of insulation. 
																	R value measures how well certain building insulation materials can resist heat.