Downspouts
Routing Downspouts Away From the Foundation
Where a downspout ends matters as much as the gutter that feeds it. A spout that empties right against the wall concentrates roof water at the foundation, exactly where you least want it. The goal is simple: move that water far enough out, onto ground that slopes away, that it spreads and soaks in instead of pooling against the house.
The discharge point is the whole problem
Picture every storm sending the water off one slope of the roof down a single spout. If it lands in a 30-centimetre puddle by the wall, that volume sits against the foundation and works its way toward the basement. Extend the same spout outward onto a graded surface and the water disperses. Nothing about the roof changed; only the landing point did.
- Extension
- A rigid or roll-out section that carries water past the backfill zone next to the wall.
- Splash block
- A shaped pad that spreads flow and protects soil from eroding.
- Grading
- The ground should fall away from the house for the first couple of metres.
- Discharge
- Onto a lawn or bed, never toward a neighbour, a walkway, or back at the wall.
Surface discharge versus buried connections
There are two broad approaches. Surface discharge keeps water visible: the spout feeds an extension and splash block, and the water runs across the yard. Buried connections route water underground, sometimes to a soakaway or, in older neighbourhoods, into a storm or combined sewer.
Buried connections are where local rules matter most. Several Canadian municipalities have programs that ask homeowners to disconnect downspouts from the sewer and redirect them to the surface, because roof water entering the sewer during storms contributes to overloading. Because requirements and any incentives differ by municipality and change over time, confirm the current position with your local drainage or environment office before connecting or disconnecting anything underground.
A note on freeze and thaw
In a Canadian winter, water that discharges onto a walkway or driveway can refreeze into ice. Aim surface discharge at planted or grassed areas that drain, and keep it clear of paths people use. Roll-out extensions can be retracted for snow clearing and redeployed in spring.
A practical sequence
- Walk the perimeter during or just after rain and note any spout that puddles against the wall.
- Check the grade: the soil should slope down and away from the foundation, not toward it.
- Add an extension long enough to clear the backfilled soil next to the wall.
- Place a splash block where the extension ends to spread flow and limit erosion.
- Re-check the same spots during the next storm and adjust length or direction as needed.
Common mistakes
- Stopping the extension too short, so water still lands in the backfill zone next to the wall.
- Aiming discharge at a neighbouring lot or a shared path.
- Leaving a low spot at the discharge point where water collects rather than drains.
- Forgetting that a clogged gutter sends water over the edge regardless of how well the spout is routed.
When the lot is tight
On narrow urban lots there may not be room to extend far from the wall. In those cases homeowners often pair a short extension with a soakaway pit or a rain garden that gives the water somewhere to collect and infiltrate. Those options are covered in the stormwater guide.