A high slope moves water more quickly and if gutters have trouble dealing with a lot of water in a short period of time an extra downspout can alleviate that issue.
													
																	Roof square footage per downspout. 
								
	
		
	
																	Therefore this roof should be equipped with 6 inch k style gutters. 
																	Primary cause for water spillage is debri in the gutter. 
																	Gutters come in a wide range of materials the cost depends on which you choose. 
																	8 inches and you have an 8 in 12 pitch. 
															
													
								
	
		
	
																	For a 5 inch k style gutter the square footage should be up to 5 500 sq ft and for a 6 inch k style gutter the square footage should be upto 7 900 sq ft. 
																	Multiplying that number by the local maximum rainfall intensity 6 8 inches per hour yields an adjusted square footage of 7 480 square feet. 
																	There is a range of different solutions for roofing underlay some are tacked or stapled while others are self adhesive ranging in price from 0 18 to 0 49 per square foot for materials only. 
																	One foot of 6 k style gutters holds 2 0 gallons of water. 
															
													
								
	
		
	
																	To do that simply multiply drainage area calculated earlier by roof pitch factor and rainfall intensity. 
																	Metal gutters vary in price from 6 to 12 for aluminum and 9 to 20 for steel to 25 or more for high end copper. 
																	A house in chicago has a roof whose actual drainage area is 1 000 square feet. 
																	A large roof is going to move a lot of water which means the downspout locations may need to be adjust to compensate. 
															
													
								
	
		
	
																	The 6 in 12 pitch factor 1 1 multiplied by 1 000 yields an effective area of 1 100 square feet. 
																	Size downspouts to fit the gutter. 
																	Intensity lasting calculated roof area intensity lasting calculated roof area 5 minutes drained per 5 minutes drained per downspout area downspout area in hr mm hr sq ft sq m in hr mm hr sq ft sq m sq in 100 sq mm sq in 100 sq mm 7 4 187 160 2 30 10 4 265 110 1 70 7 1 181 170 2 40 9 9 251 120 1 70 1 8 46 660 9 50 3 1 77 390 5 70. 
																	For the vast majority of rains gutter and downspouts sizes considerably less than recommended will do the job. 
															
													
								
	
		
	
																	Two hundred feet of gutter can cost anywhere between 660 and 4 500. 
																	Multiplying that number by the local maximum rainfall intensity 6 8 inches per hour yields an adjusted square footage of 7 480 square feet. 
																	If this distance measures 4 inches you have a 4 in 12 pitch. 
																	On a ladder beside the roof place the level a foot or so up the roof hold it level and measure from the 12 inch mark on the level s bottom straight down to the roof. 
															
													
								
	
		
	
																	Roof area the locale s rainfall intensity and gutter capacity determine how many square inches of downspout are needed. 
																	Labor costs vary based on the type of underlay at 0 15 to 0 22 per square foot. 
																	Vinyl gutters cost 2 to 5 per linear foot. 
																	A square inch of downspout can drain 1 200 square feet of roof during a rain with an intensity of one inch per hour. 
															
													
								
	
		
	
																	After you have calculated the square footage use following calculations. 
																	One foot of 5 k style gutters holds 1 2 gallons of water. 
																	For a 2 400 square foot roof you can expect to spend 792 to 1 704.