As part of the roofing system, the gutters and downspouts are often overlooked, especially the downspouts. But a downspout plays a very important role in protecting your home from water damage. Downpipes carry water from the roof to the ground, depositing rainwater away from the foundation of your home and protecting the landscaping from soil erosion. Knowing the purpose and the importance of downspouts will help prevent costly damage and repairs in the future.
What is a Downspout?
Part of the gutter system, a downspout is a pipe positioned vertically at the bottom of the gutter section. A house generally has more than downspout, placed every 35 to 50 feet depending on the configuration of the roof and the size of the home.
Materials used in the manufacture of downspouts include aluminum, vinyl, and copper. The majority of gutter systems for residential buildings in North America are made of aluminum.
They are available in a variety of sizes. A standard gutter system for an average-sized home includes 5” gutters and 2 x 3 inch downspouts in areas with a light to medium annual rainfall. If your home consistently receives lots of rain, you might need 6” gutters or 3 x 4 inch downspouts or a larger sized gutter system.
How Downspouts Work
Regardless of the type of gutter system all downspouts function in the same way. Downpipes are typically connected to the gutter section by a gutter outlet and then attached to an exterior wall by brackets. Elbows change the direction of the water being expelled by the gutter system and can be found at the top of the pipe where it connects to the gutter outlet and at the bottom so that the rainwater is drained the appropriate distance away from the foundation.
Location of Downspouts
Downpipes are typically installed at or around the corners of the roof, where two exterior walls meet. If the downspouts cross a walkway, are positioned too close to an entry door, or drain directly on to a deck or a patio, they could cause you trouble in the future. Downspouts should always be located away from high-traffic areas and any other types of obstructions.
Effective Downspout Placement
Effective downspout placement is important. The water from the roof collected by the gutters flows toward the gutter outlet and then out of the gutter system through the downspouts. You want to ensure that rainwater is deposited far enough away from the foundation where it would do any mischief: gutter installers recommend a distance of five to seven feet from an exterior wall.
If the downspout deposits rainwater too close to your house, use a downspout extender, an attachment that lets you determine where and how far away the water will be drained.
There should be a downspout for every 40 linear feet of guttering. Especially when you have a large house, following this general rule of thumb is a cost-effective way to “waterproof” your basement and protect the foundation from shifting or cracking.
Maintaining the Gutters
To be effective and fully functional downspouts depend on how well the gutters are maintained. Debris that builds up in the gutters channels can form clogs. Clogs block water from making its way to the downspouts. Loose debris can work its way down the pipe and cause blockages within the downspout itself.