Drainage, Perimeter & French Drains in Nanaimo

How does a French drain work?

A perforated pipe sits in a gravel-filled trench sloped away from your foundation. Water finds its way into the gravel, drops into the pipe, and travels by gravity to an outlet that drains downhill on its own — no pump needed on most lots.

Does your property need one?

If water pools against your foundation, a crawl space stays damp, or your yard holds water for days after rain, a French drain is usually the fix. We walk the property, check the slope and the soil, and tell you straight whether drainage — or something else — is the actual problem.

What's the difference between a perimeter drain and a French drain?

A perimeter drain is the one that runs around your foundation. A French drain is the same drain anywhere else on your property — along a fence line, across a wet lawn, behind a retaining wall. We build both the same way: perforated pipe in drain rock, on a grade of at least 1%, running to an outlet that gets away downhill on its own.

Where do you install drains?

We put drains in around Nanaimo, Lantzville, Cedar, South Wellington and Extension, here in British Columbia. Most of the ground we dig is glacial till over sandstone and shale, with pockets of well-draining Quadra Sand nearer the water. On clay and till we cut the trench deeper and bed the pipe in more rock, because water crawls through that ground and the pipe has to sit low enough to catch it.

What does your yard look like when we finish?

We put the ground back the way we found it as far as we can. We backfill the trench, walk it in and rake it out. The turf goes back on top where we lifted it in one piece. You will see the line of the trench for a while, and it settles a little over the first wet season. Tell us if it dips and we will come back and top it up. Anything we could not save, like a shrub sitting in the line or a bit of lawn that tore, we point out at the walk before we dig. That way it is not a surprise at the end. Give it a season and you will have trouble finding where we were.

How it works

1. 1

   Site walk — We walk the site and check slope, soil and where the water is actually coming from.

2. 2

   Trenching — We cut the trench to the depth and grade the water needs to move.

3. 3

   Pipe & gravel — We lay fabric-wrapped perforated pipe and bed it in drain rock.

4. 4

   Outlet & restore — We run the outlet somewhere it drains downhill on its own, backfill, and restore the surface.

Local conditions

Our winters here are long and wet, and that is when your drain has to do its work. Where the ground is heavy clay or the water table sits high, we dig deeper and pack more rock around the pipe. That way the system still keeps up in December, when the ground is already full of water.

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