8 3 4 4 8 2 20.
													
																	Foam board insulation rigid insulation r value chart. 
									
	
		
	
																	For example insulating a 10 square foot wall area to r 15 costs about 3 40 to 4 00 with fiberglass insulation while a comparable r value for rigid foam costs roughly 10. 
																	R 0 77 30 phenolic foam insulation r values. 
																	I ve written several posts about how to insulation basement walls in which i promote the use of foam board insulation as the first line of defense against moisture and mold. 
																	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. 
															
													
									
	
		
	
																	Foam board insulation types. 
																	4 8 7 21. 
																	Fiberglass insulation is less than half the price of rigid foam insulation when calculated by r value per square foot. 
																	There are three basic foam insulation board products on the. 
															
													
									
	
		
	
																	1 844 446 7858 my account. 
																	Because of this i often get questions about which type of foam board insulation to use and what r values these products provide. 
																	Corrosion problems when in contact with steel roofing moisture. 
																	There is also less waste with fiberglass insulation. 
															
													
									
	
		
	
																	4 5 21. 
																	Very good air bypass leak sealing properties. 
																	Our r value guide to rigid insulation includes the doe s recommended insulation by zone chart r value calculator and base building material r values chart.