Guides
Excavations and trenches
Written by the OK Sécurité team · Updated September 9, 2026
Cave-ins and utility strikes are high-consequence events. Prevention blends soil understanding, protective systems, water control, and access rules.
Before you dig
Locate buried utilities and follow approved clearance methods. Mark zones and keep drawings current.
Assess soil type, depth, nearby loads (vehicles, stockpiles), and space for sloping or shoring.
Wall stability
Pick sloping, benching, or shoring based on analysis. Watch for cracks or water that signal movement.
CSTC 3.15.3 (5): no materials within 1.2 m of the top; no vehicles or machines within 3 m unless the shoring is designed for that.
Water and conditions
Water reduces strength and complicates egress. Plan pumping, temporary drainage, and safe entry.
Reassess after heavy rain or freeze-thaw cycles.
Access and work inside
CSTC 3.15.3: from 1.2 m, shore by default (unless an exception in that article applies). 3.15.4: ladders every 15 m, standing on the bottom, extending at least 1 m. There is no “time under an unprotected wall” allowance.
Earthwork/drainage lists help cover recurring field items.
Protection methods depend on context and regulations. Have competent people validate technical choices. For information only — this is not legal advice. OK Sécurité is an independent company with no affiliation to the CNESST: we are not mandated, endorsed or certified by it. Where there is any discrepancy, the official text published by Légis Québec or the CNESST prevails.
Sources
Informational only. Confirm obligations with your prevention program and:
- CNESST — Mesures spécifiques pour les chantiers de construction
- Safety Code for the construction industry (CSTC) and Regulation respecting occupational health and safety (RSST)
Official rules
Related checklists
Heavy-work lists related to digging:
Common questions
- When is an engineer or stability study needed?
- It depends on depth, soil, loads, and methods. When uncertain, bring expertise rather than improvising.
- How do we avoid buried electrical contacts?
- Follow locate procedures, standoffs, and excavation rules near networks. Never assume a line is dead.
- What should we watch during the shift?
- Walls, water, traffic, signage, access, hoisting near the edge, and soil behavior after weather events.
- Does OK Sécurité cover earthwork?
- Yes—earthwork/excavation lists are available alongside other heavy-work checklists.