Place downspouts in discrete places if possible, install oversized 3 × 4 inch downspouts. Tilt the long gutters (40 feet or more) in both directions from the center and place a downspout at each end. There are a few factors that need to be considered when determining where to place gutter downspouts. First you should consider how many downspouts you'll need.
The typical recommendation is one downspout for every 20 to 30 feet of gutters. The next factor to consider is the slope of the roof, since the slope will cause water to flow in a certain direction. Channels and downspouts must be installed with this inclination in mind so that water flows downward instead of remaining stagnant in the gutter channel. Finally, you should think about the design of your home: gutter downspouts should not be emptied near a mezzanine, a basement window, or any other place that could allow water to seep inside.
The Spoutoff can be installed with new rain gutter systems or can be adapted to current gutters and downspouts that are in good condition. For gutters larger than 40 feet, it is best to tilt the gutter down from the center to a downspout at each end.