The way it works is simple.
													
																	Roof system r values. 
									
	
		
	
																	Types of roof insulation. 
																	To convert the r value of a specific thickness of a material to rsi divide the r value by 5 67826. 
																	0 00 per inch of thickness tpo. 
																	0 24 per inch of thickness epdm. 
															
													
									
	
		
	
																	It uses the iso thermal planes method the same method as used in nzs4214 2006. 
																	0 24 per inch of thickness. 
																	5 0 per inch eps insulation. 
																	The average r value for some common roof materials include. 
															
													
									
	
		
	
																	0 34 per inch of thickness bur smooth. 
																	To convert rsi to r value multiply the rsi by 5 67826. 
																	The higher the r value the better a material performs as a thermal insulator. 
																	This webpage calculates the r value of walls roofs and suspended floors for most insulation material r values. 
															
													
									
	
		
	
																	For example two inches of extruded polystyrene with an r value of 11 has an rsi of 1 93721. 
																	R value table for roofing materials and building insulation. 
																	3 85 per inch polyiso. 
																	6 6 per inch of thickness metal. 
															
													
									
	
		
	
																	R value because many states or regions require that a roof system have a minimum amount of thermal resistance on commercial industrial and or institutional buildings. 
																	Here are the r values of the most popular commercial roofing systems. 
																	6 6 per inch xps insulation. 
																	The higher the r value the more the material insulates. 
															
													
									
	
		
	
																	Eps based claddings directly fixed on timber framing. 
																	R value is used as a measurement of the effectiveness of thermal insulating materials.