What is a Downspout Guard?

A downspout guard is a device designed to prevent leaves, sediment and other debris from clogging a downspout. It can also keep many contaminants out of collected rainwater. Downspout guards are often used by homeowners to prevent damaging back-ups of water during storms. They are frequently used by commercial and industrial building maintainers as well.

Debris can be filtered from gutters and downspouts at several different levels. The most basic way is with a simple wire "bird cage" downspout guard. These are often made of flexible aluminum or copper and can be inserted into the top of a downspout pipe. This design should block leaves, branches and other large objects, but may do nothing for sediment and small debris. The blocked material will often clog up the gutter, but not the pipe.

To capture extra debris, a more elaborate downspout guard can be used in the pipe below a gutter. One design uses a box with small holes in an angled lid to pass water through while deflecting debris. Another uses an open box with a mesh screen to collect materials; the screen must be cleaned often, however. A variation on this design includes a removable collection basket with at least one filter. This guard fits in-line in the pipe and may include a second, finer filter to remove debris missed by the first one.

One of the best ways to help a downspout guard do its job is to keep as much material out of the gutter as possible. A very fine mesh screen can be attached to the entire gutter, making it hard to clean out what does get through. Another solution is a metal bottle brush-like guard, which collects leaves and other debris—it can be removed easily for cleaning. A more elaborate design includes a treated foam insert which fills most of the gutter space. The foam filters out sediment and larger debris while leaving a small channel for water underneath.

A combination of a removable downspout guard and a gutter filter may be the most effective way to prevent clogs. It will often remove the most sediment and other small debris as well. This is particularly important if the downspout feeds a rain barrel or underground pipe. An additional fine filter near barrel level may be needed to keep materials out of fragile barrel screens. One near ground level can also prevent a costly dig to replace a clogged landscaping pipe.

For rainwater collection or downspouts which collect pavement or industrial runoff, oil and grease can also be filtered. A special type of downspout guard can separate these as well as some heavy metals and organics. It includes stainless steel mesh, a hydrocarbon filter and optional filters for other types of materials. It installs in-line in a downspout pipe and can store a large amount of filtered waste.

Locations very close to a driveway or where heavy equipment is often used may need a different type of device. Also called a downspout guard, it protects a length of downspout from vehicle damage. Designed to be attached to either a wall or a column, this type of guard is often very sturdy. It can also be used to protect electrical, mechanical or plumbing pipes.