Excavation & Site Preparation · Duncan
Foundation Digging and Footings in Duncan
Footings and foundation walls cut to the surveyor's levels, with the water table planned for rather than discovered.
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Excavation quote request
The more detail about the property and the work, the closer the first number will be. We send a written quote after we visit your site.
Duncan Excavating provides foundation digging for footings and foundation walls across Duncan, North Cowichan and Cowichan Bay. On valley-floor soils running to 30 metres deep, we plan around a median winter water table of 2.4 metres. We cut to surveyor's levels and backfill once forms come down.
A foundation dig is measured work. The levels have to be exact here, and the tolerances are tighter than on any other part of the job. Two things move your price the most: what the bucket hits, and how wet the hole is.
What moves your price is depth, whether the material is diggable sand and gravel or rock needing a breaker, how far spoil has to travel, and whether the excavation is deep enough to need shoring.
Depth, water and the 1.2 metre line
Under the OHS Regulation, before a worker enters any excavation over 1.2 metres deep the sides have to be sloped, benched or shored, and excavated material has to be kept back at least 60 centimetres from the edge of a trench and 1.2 metres from any other excavation. Past 6 metres deep, or where a structure sits adjacent to the dig, written instructions from a qualified registered professional are required. Whether the dig passes that 1.2 metre threshold is usually what separates a straightforward footing dig from an expensive one.
Backfill, drainage and what gets signed off
We quote footing work and perimeter drainage together, because a foundation stays dry or wet depending on how the backfill is done. Your CVRD building permit application requires several supporting documents. You need a site plan from a BC Land Surveyor, a riparian declaration if work sits within 30 metres of a stream or ravine bank, an ALC Notice of Intent for soil or fill removal, and a geotechnical report with a Schedule B where needed.
What a foundation scope usually covers
Building pad preparation
Stripping and preparing the pad to the elevation the drawings call for.
Footing and wall excavation
Cutting footings and foundation wall lines to the surveyor's levels.
Shoring and benching where required
Sides sloped, benched or supported where the dig passes 1.2 metres.
Backfill and compaction
Backfilled in lifts against finished walls and compacted.
How a foundation dig runs
- 01
Levels and layout — Working from the drawings and the surveyor's stakes, with the dig lines set before anything is stripped.
- 02
Locates and access — BC 1 Call locates in hand, and a route onto the pad that a loaded truck can actually use.
- 03
Dig to grade — Cut to the specified elevation, with spoil kept back from the edge and stockpiled or loaded out depending on whether it is going back in.
- 04
Backfill and compact — Backfilled in lifts once the walls and drainage are in, and compacted rather than simply pushed back.
Local conditions
The lower Cowichan features three stacked sand and gravel aquifers with median well depths of about 8, 23 and 43 metres, separated by layers of silt, clay and till. When we dig your foundation, the shallowest aquifer holds groundwater at a median depth of 2.4 metres below the surface. One provincial observation well near Duncan swings about 3.1 metres between its winter high and its summer low. On developed floodplain lots, provincial mapping shows placed fill material, which behaves differently from undisturbed ground when we dig.
People also ask
How deep does a footing excavation have to be?
Depth comes from the structural drawings, not from a rule of thumb. What the OHS Regulation sets is the safety threshold: any excavation over 1.2 metres that a worker enters must be sloped, benched or shored.
What happens if the dig hits rock?
The machine changes. Rock is broken with a hydraulic breaker on a larger excavator rather than dug, which is a different rate and a different timeline. Near-surface bedrock under a metre is mapped across most of the Malahat Ridge area, so it is a live question south of the valley floor.
Is a building permit required before excavating?
For a new building in the CVRD electoral areas, yes — a permit is required before construction, and the application requires the site plan, land title search and any riparian or Agricultural Land Commission confirmations up front. The City of Duncan states that a building permit, when required, must be issued before any work can take place.
Keep exploring
- Compare excavation costsOur hourly machine rate, typical project ranges, and the tipping and permit fees for your job.
- Permits and setbacksWhich authority governs a parcel, the setbacks and depth thresholds that apply, and the notices that have to be filed first.
- Lot Clearing and GradingLand clearing in Duncan and the Cowichan Valley — brush, stumps, topsoil, grading. We walk your lot first, then quote each stage and the haul-out separately.
- Perimeter Drains and DitchingWe install perimeter drains, foundation drainage, and water and sewer service trenching in the Cowichan Valley, where groundwater medians sit at 2.4 metres.
- Duncan Excavating home
Ready for a quote on excavation in Duncan?
We quote excavation across the Cowichan Valley after a site visit.