Guide
The 8 types of gutter downspout extensions
The gutter catches the water. But it's the extension that decides where it ends up: away from your foundation, or right against it. Here's every option, its real advantages, its limits in winter, and how to choose.
What an extension does (and why your town cares)
Without an extension, a downspout empties right at the base of the wall, where the foundation is most vulnerable. During a heavy downpour, the roof of an average house can send hundreds of litres of water to a single spot. That water saturates the soil, puts pressure on the foundation wall and often ends up in the basement.
The extension carries the water to an area where the ground slopes away from the house. It's simple, inexpensive, and often required by a municipal bylaw. Many towns also ask you to disconnect downspouts from the foundation drain, to avoid overloading the sewers during heavy rain. See your town's rule →
The 8 types of extensions
1. Rigid straight extension Aluminum or vinyl
The classic extension: a straight section that slips onto the bottom elbow of the downspout.
- Cheap and easy to find
- Good flow
- Can be cut to the length you want
- Gets in the way of mowing and snow removal
- Often gets crushed or knocked out of place
- Ordinary look
2. Hinged (flip-up) extension With a hinge
A rigid extension mounted on a hinge: you flip it up against the wall to mow, walk by or clear snow.
- Keeps the advantages of the rigid type
- Stows away in one move
- Handy near walkways
- You have to remember to lower it before it rains
- The hinge can wear out or freeze
3. Roll-out extension Unrolls on its own
A thin plastic tube that stays rolled up at rest and unrolls under the water pressure when it rains.
- Very discreet in dry weather
- Inexpensive
- Fragile: tears and punctures
- Low flow during heavy downpours
- Must come off in winter, or it freezes and breaks
4. Flexible accordion extension Corrugated plastic
A corrugated tube you can bend and stretch to get around an obstacle.
- Adapts to awkward angles
- Quick to install
- The folds trap debris
- Crushes easily
- Limited lifespan in the sun
5. Swivel extension (TurnSpout) Made in Canada
An extension that swivels 360° and tilts 25°. You point it where the water should go, then turn it when it's in the way.
- Permanent installation, in 5 minutes
- High-density plastic, from -40 °C to +80 °C
- UV-resistant, several colours
- Maximum flow
- Costs more than a basic extension
- Fits 2⅝ in., 2×3 in. and 3×3 in. (not very large downspouts)
6. Splash block Concrete or plastic
A small sloped slab set under the downspout outlet. It spreads the water out and protects the soil from erosion.
- Prevents a hole from forming at the foot of the downspout
- No moving parts
- Only moves water a few inches away
- Usually not enough to meet a minimum discharge distance
- Often an add-on, not a solution
7. Buried pipe To a distant outlet or a dry well
The downspout connects to a buried, non-perforated pipe. It carries the water far from the house, to an open-air outlet or a dry well.
- Invisible
- Lets you release water far away
- Nothing to move for mowing or snow removal
- Requires digging
- Needs a steady slope, or water sits and freezes
- Can clog, so a basket or filter at the top is recommended
- Never connect it to the foundation drain
8. Rain barrel With an overflow
The downspout empties into a barrel, and the water is used for watering. The overflow must also be directed away from the foundation.
- Saves drinking water
- Many towns subsidize the purchase
- The overflow has to be handled like a downspout
- Must be emptied and stored before winter
- Requires modifying the downspout
Comparison table
| Type | Cost | Discharge distance | Winter | Discretion |
|---|---|---|---|---|
| Rigid | $ | Good | Fair | Low |
| Hinged | $–$$ | Good | Fair | Medium |
| Roll-out | $ | Medium | Remove it | Good |
| Accordion | $ | Medium | Poor | Low |
| Swivel (TurnSpout) | $$ | Good, adjustable | Very good (-40 °C) | Good |
| Splash block | $ | Very short | Good | Medium |
| Buried pipe | $$$ | Excellent | Varies (slope!) | Excellent |
| Barrel + overflow | $$ | Depends on the overflow | Empty it | Medium |
Which one to choose for your yard
The downspout faces a lawn you mow
A swivel or a hinged extension: you turn it or flip it up to get by, then put it back.
The downspout is next to the driveway or stairs
A swivel pointed toward the flower bed, or a buried pipe if you want the outlet further away. Avoid anything that sends water onto a surface where it will refreeze.
The yard slopes toward the house
An extension won't fix poor grading. The water has to go far enough, often with a buried pipe, and ideally the grading should be corrected.
You want to collect the water
A barrel, with an overflow fitted with an extension. We can modify your downspout for a rain barrel.
You want something you can forget about
A TurnSpout swivel: permanent installation, cold-resistant, nothing to remove in the fall.
The 5 mistakes to avoid
- Sending water toward the neighbour, the street or the sidewalk. Often prohibited, and a source of conflict.
- Connecting the downspout to the foundation drain. Prohibited in many towns, and risky for your basement.
- An outlet onto a hard surface that freezes (driveway, stairs, patio).
- Leaving a roll-out extension outside in winter. It won't make it to spring.
- An extension that's too short on flat ground: the water comes back toward the wall.
