How long should a downspout extension be?

Long enough to release water at least 4 to 6 feet from the foundation, onto ground that slopes away from the house.

Are flexible downspout extensions good?

They are handy for getting around obstacles on short runs, but they can sag and trap debris, so keep them sloped and clear.

What is a downspout diverter?

A fitting in the downspout that sends water another way, most often into a rain barrel, then back down the pipe when the barrel is full.

Can I mow over downspout extensions?

Use a hinged or flip-up extension that lifts out of the way, or bury the line so nothing is above ground.

Guides

Downspout Extensions and Diverters: Getting Water Away

A downspout that dumps water right at the wall undoes most of the work the gutter did. A few feet of extension is often the cheapest drainage improvement a house can get.

Updated 2026-10-26 · Gutter Fixing Editorial Team

Downspout extensions, also called gutter extensions or drain extenders, attach to the bottom elbow of a downspout and carry water farther from the house before releasing it. They come in rigid metal, flexible plastic, roll-out sleeves and hinged designs. Choosing between them comes down to how far the water needs to go, what is in the way, and how they will look.

How far should water go?

Many guides recommend discharging roof water at least 4 to 6 feet from the foundation, and farther where the ground is flat, the soil is clay or there is a basement. The ground at the outlet should slope away from the house so water keeps moving. If you cannot get enough distance above ground, a buried line is the next step; the underground downspout drainage guide covers that.

Types of gutter extensions

Type	How it works	Good for
Rigid metal or vinyl	A straight length of downspout pipe attached to the bottom elbow	Clean look, matching color, permanent runs
Flexible corrugated	Bendable plastic pipe that stretches and turns corners	Getting around steps, shrubs and paths
Roll-out sleeve	A flat tube that unrolls when water fills it and rolls back after	Short distances, hiding when dry
Flip-up or hinged	An extension that pivots up out of the way	Mowing, walkways and driveways
Splash block	A shaped concrete or plastic pad under the outlet	Spreading short discharges and stopping erosion

Rigid extensions

A straight piece of the same downspout pipe, in the same color, makes the neatest extension. It is attached to the bottom elbow with screws and can run several feet across a bed or lawn. It can be knocked off by mowers and people, so a hinge at the elbow lets it flip up when needed. Rigid extensions in aluminum match the gutters; vinyl versions are cheaper.

Flexible gutter extensions

Flexible gutter extensions are ridged plastic pipes that stretch and bend. They make it easy to route water around a corner, under a deck step or along a path. The ridges trap some debris and they can sag, so they work best on short runs with a steady slope. Many come with an adapter for both rectangular and round downspouts.

Splash blocks and splash guards

A splash block is a shallow trough set under the downspout outlet. It slows the water and spreads it, stopping erosion right below the pipe. It only moves water a foot or two, so it should be combined with ground that slopes away. Splash blocks need to be set with their slope away from the house; a block tipped toward the wall makes things worse.

Gutter downspout diverters

A diverter fits into the downspout itself and sends some or all of the water another way. The most common use is filling a rain barrel; when the barrel is full, water carries on down the pipe. Other diverters switch flow between a surface extension and a buried drain, or let you close off a drain in winter. Rain barrel diverters are covered in more detail in the rain chains and rain barrels guide.

Fitting tips

Attach extensions with screws so they do not blow off or get knocked away.
Keep a steady downhill slope with no dips where water sits.
Aim the outlet at a lawn or bed that slopes away, not at a path or a neighbor.
In winter, check that extensions are not frozen shut or buried in snow.
Check extensions after mowing and yard work; they are often moved and not put back.

Extensions on two-story homes

Downspouts on taller homes carry more water at higher speed. The bottom elbow and extension need to be strong and well attached, and a splash block at the end helps. Where an upper downspout drains onto a lower roof, a short extension on the roof, sometimes called a splash diverter, spreads the water across the shingles rather than wearing one spot.

When extensions are not enough

If water still pools near the foundation, or the basement stays damp after storms, the problem may be the grading around the house, an undersized downspout, or a clogged pipe. Contractors in our network who handle downspout repair can add or upsize downspouts, fit permanent extensions, or lay a buried drain.

Extensions and grading work together

An extension only works if the ground at its end carries water further away. If soil has settled into a dip next to the house, water released at the end of the extension can run back to the wall. Building up the soil so it falls about six inches over the first ten feet from the foundation, where space allows, makes every extension more effective. Mulch and gravel beds should slope the same way.

Choosing extensions for looks

Extensions are often the most visible part of a drainage fix. Matching the extension to the downspout color, using a rigid piece rather than a bright plastic hose, and routing it along a bed edge rather than across the lawn make it far less noticeable. Decorative splash blocks in stone or cast metal can turn the end point into a small garden feature.

Common problems

Extensions disconnected by mowers, pets or kids and left on the lawn.
Flexible pipes sagging into a U that holds water and freezes.
Roll-out sleeves torn or blocked by leaves.
Splash blocks set tipping toward the house.
Extensions emptying onto a neighbor's yard or a public sidewalk.

Extensions in winter

Snow piles and ice can block the end of an extension so meltwater backs up into the downspout and freezes. Clear a path at the outlet after big snowfalls, and in very cold areas, consider a short rigid extension that drains completely rather than a flexible one that holds water in its ridges.

Flexible, retractable and automatic extensions

Flex downspout pipe is corrugated plastic that bends around corners and stretches to length; a flex drain downspout extension usually fits a 2x3 or 3x4 outlet with a rubber or plastic adaptor and extends from about 2 to 8 feet or more. A collapsible or expandable downspout extension works the same way and packs down short when not in use. Perforated flexible pipe lets some water soak in along the way, which suits sandy soil but can leave soggy ground in clay.

A retractable downspout extender rolls up when dry and unrolls when water flows through it, so it stays out of the way of mowers. An automatic downspout extension does a similar job with a weighted or spring hinge that drops down when water arrives. Both suit paths and lawns where a fixed extension is a trip hazard.

Gutter spout extenders, hoses and diverters

A gutter spout extender or gutter spout extension is a short add-on at the bottom elbow. Gutter extension hoses are soft tubes that clip on and run water further across a lawn. A down spout diverter switches flow between a rain barrel and the pipe. Each one should end where the ground slopes away from the house, at least a few feet from the wall.

Choosing color and size

Black, brown and white downspout extensions are the common stock colors and blend with most gutter systems. Match the size to the downspout: a 4x5 gutter downspout extension needs a larger adaptor than a standard 2x3. A 10 ft extension or longer run may need support so it does not sag and hold water.