However you can only use this pitch with built up roofing or specialized synthetic roofing.
													
																	Minimum roof pitch for dormers. 
									
	
		
	
																	A shed dormer on the other hand is usually had on homes with a roof pitch of at least 8 in 12 or steeper. 
																	Pitched roofs can also be used to incorporate roof lights angled in a specific direction or dormer windows. 
																	This image shows a relatively shallow roof pitch of 15 degrees. 
																	The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run. 
															
													
									
	
		
	
																	However rise over run is more efficient and easier to understand for the average diyer. 
																	A 4 12 pitch is around 18 5 degrees but not exactly. 
																	Thus a 4 12 pitch would be a 33 slope. 
																	The loft space would be much larger with a roof pitch of 45 degrees. 
															
													
									
	
		
	
																	This type of dormer needs a roof pitch shallower than that of the original.