A channel drain is a linear grated trough set into the paving to collect water along a line and pipe it away. It is what you use where the surface cannot be re-graded enough, typically across a garage entrance, at the bottom of a sloped driveway, or where a patio meets the house.
The trough and the grate are the visible five percent of this job.
What makes it work or fail is the pipe: it needs continuous fall from the channel to a discharge point that is genuinely lower and genuinely open, whether that is daylight at a slope, a dry well sized for the volume, or a storm connection where one legitimately exists.
A channel piped into a flat run holds water, and a channel piped into a dead end holds water and then freezes solid in January, at which point it is a decorative metal strip across your driveway. So the first thing we establish, before quoting anything, is whether an outlet exists.
If it does not, we say so rather than installing a drain that cannot drain. The channel itself is bedded in concrete, set two to three millimetres below the finished paving so water runs into it rather than over it, and the pavers are cut to it cleanly.
Daylight, a dry well or a legitimate storm connection. If none exists, a channel drain is not the answer and we will say so.
Cut and excavate the line
The paving is cut cleanly along the run and the trench taken to a depth that gives the pipe continuous fall to the outlet.
Bed the channel in concrete
Set two to three millimetres below the finished surface so water runs in rather than across, and held so traffic cannot move it.
Cut the pavers to it
Stone is cut to the channel rather than snapped and packed, because a gap beside a drain is where the next washout begins.
Winter Damage
Why a badly piped channel freezes
A channel with fall on its pipe drains between rains and sits empty, so there is nothing in it to freeze. One piped into a flat run holds standing water permanently, and in January that becomes a block of ice at exactly the point the driveway needed to drain.
The fall on the pipe matters more than the product on the surface. See how pooling water behaves in the same conditions, what grading and slope can solve without one, and how porch repair uses one at a door.
Fall on the pipeWhat matters
Freezes solidA flat pipe
RainsDrains between
Related Work
Other drainage work in Toronto
What a channel drain is usually installed alongside.
When there is not enough fall available, typically at a garage entrance or where a patio meets the house and the door sill caps how much you can raise the surface.
To daylight at a slope, a dry well sized for the volume, or a legitimate storm connection. Establishing that comes before quoting rather than after.
Not if the pipe has continuous fall, because it drains between rains and sits empty. One piped into a flat run holds water and becomes a block of ice.
Deep enough that the pipe has fall all the way to the outlet, which is why the outlet location determines the excavation rather than the other way around.
Roughly $60 to $120 per running foot including supply, cutting the paving and making the connection. Long pipe runs to a distant outlet add to that.
Twice a year suits most, spring and after leaf fall. The grate lifts out and the channel gets flushed. A drain nobody has opened in five years is usually the reason the water is back.
