Breaking ground without striking a live service is basic discipline, yet too many sites still rush the paperwork, skip the scans, and hope for the best. A permit to dig is not a form; it’s a method of controlling change, confirming competence, and setting clear hold points around buried utilities. Getting it right means joining up design, surveys, supervision, and the crew on the shovel, then keeping it live as conditions shift during the shift.
TL;DR
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– Treat the permit as a live control with hold points, not a one-off form.
– Combine records, competent scanning, and trial holes before any machine bite.
– Hand dig within tolerance zones, control plant movements, and brief at each shift.
– Stop and escalate on any discrepancy, damage, or uncharted service — no grey areas.
Service-safe excavation: the playbook
# Stage 1: Build the picture before anyone lifts a spade
/> Start with recent utility records and designer intent. Collate service drawings, mark up the work area, and make sure everyone uses the same reference points. Plan scanning using competent people and suitable kit; in congested zones, consider both cable avoidance tools and GPR to reduce blind spots.
Agree how the markings will be transferred to site — paint, flags, or pin markers — and protect them from traffic and rain. If work slips on programme, repeat the scan; yesterday’s dig can change today’s risk.
# Stage 2: Permit, roles, and hold points
/> Draft a permit that’s specific: location, depth, known services, method for trial holes, hand-dig limits, plant type, and isolation arrangements where practicable. Name the permit issuer, the machine operator, the banksman, and the person in charge of the works. Build in hold points — for example, “no machine digging until trial pit confirms clearance,” and “stop on any variance from mark-up.”
Revalidate the permit at each shift change or weather event that affects markings or ground conditions. Toolbox the crew, show the marks on the ground, and confirm what will trigger a stand-down.
# Stage 3: Prove, expose, and make it safe to dig
/> Cut turf and break out surfaces by hand in the tolerance zone around any suspected service. Use insulated tools where appropriate, and adopt vacuum excavation in tight, high-risk corridors where it’s available and competent operators are on hand. Keep edges supported and protected: treat trench support and edge protection as temporary works with a named checker.
When services are found, expose enough length to identify type, route, and depth, then protect them with suitable covers, padding, and clear signage. Update the mark-up and brief the whole team before any machine works restart.
# Stage 4: Controlled mechanical excavation and change management
/> Use the right plant for the dig size and proximity to services, with a trained operator and a dedicated banksman. Set slew and approach limits, keep bucket teeth away from known lines, and hand dig the last section to any crossing or tie-in. Maintain an exclusion zone around the machine and keep pedestrian interfaces clean and simple.
Any variation — depth not as drawn, extra duct, odd material — triggers a stop and a call to the supervisor. Record the change, re-brief, and only proceed when the permit is updated. On completion, capture as-builts and reinstate service protections so maintenance and follow-on trades aren’t set up to fail.
A morning on a mixed-use project: what it really looks like
/> It’s 07:45 on a city-centre job, and a groundworks gang is cutting trial pits for a drainage run parallel to the pavement. The permit issuer runs a quick briefing at the kerb, points to fresh orange and blue marks, and confirms the hold point: no machine within half a metre of suspected lines. The scan shows a telecoms duct not on the drawings, so the first pit is hand dug. Twenty minutes in, a plastic duct appears at 350 mm, not 600 mm as expected. Work stops, a vac-ex unit is called, and the permit is updated to widen the tolerance zone. By 10:30, the route is proved, temporary trench support is in, and the machine starts peeling back safely under banksman control. The as-built sketch is snapped on a tablet before lunch so the afternoon crew aren’t guessing.
Common mistakes with permits around live services
# Treating the permit as admin
/> Filling a form in the cabin and leaving it there means the controls never reach the shovel. The permit needs to drive behaviour on the ground.
# Scanning from the kerb and calling it good
/> Rushed or poorly set-up scans miss shallow or non-conductive services. Competence and method matter as much as the kit.
# Skipping revalidation after rain or night works
/> Paint marks wash off and ground heave moves clues. Reconfirming before a fresh bite saves strikes.
# Letting “just one bucket” creep in
/> Pressure to progress nudges crews past hold points. One uncontrolled bite near a live cable is all it takes.
Supervisor’s toolbox and interfaces checklist
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– Confirm the service plan on the ground: marks visible, protected, and matched to the permit sketch.
– Walk the dig line with the operator and banksman; agree stop lines and hand-dig zones.
– Check trial holes are opened, logged, and signed at the hold point before plant starts.
– Verify trench support and edge protection are adequate for the depth and ground; stop for any sloughing.
– Keep conflicting activities out of the corridor: no deliveries, storage, or pedestrian routes through the exclusion.
– Plan for the “what if”: tools for service identification, emergency contacts, and immediate isolation steps where possible.
Bottom line
/> Live services don’t forgive shortcuts. A good permit ties together information, competence, and staged verification, and it stays live as the dig changes shape through the day. Do that reliably and you protect people, programme, and reputation.
# Actions to land this in the next week
/> Pick one active excavation and rebuild the permit around clear hold points; brief it at the pit edge. Walk your scanning contractor through your method statement and agree how re-scans will be triggered. Set a simple rule with operators: no machine bite until the trial hole photo is on the permit. Add vac-ex to your options list for congested zones and identify who’s competent to run it. Start capturing as-built photos and sketches as standard close-out on every trench.
The inspection focus is shifting towards how permits control change in real time, not how they read in the office. Ask at your next briefing: where is our stop line, who can call it, and how fast do we re-brief when the ground surprises us?
FAQ
# When do we need a permit to dig on a small job?
/> Use a permit whenever ground is being broken where services may be present, including small pits or fence posts. The scale of the document can match the job, but the principles — information, verification, hold points, and supervision — remain the same.
# How often should we rescan an area during a phased dig?
/> Rescan when conditions change: after rain, after adjacent excavation, or when programme gaps mean markings may be out of date. In phased works, build re-scans into the sequence so each bite is informed by fresh information.
# Who should issue and control the permit on a busy site?
/> A competent person with authority to stop work should issue and manage the permit, often a site manager or supervisor trained for the role. They must be present enough to enforce hold points and handle changes without delay.
# What’s the safest way to expose services in crowded corridors?
/> Hand digging with insulated tools is a baseline, and vacuum excavation is a strong option where space and competence allow. Expose enough length to read the route and protect it with covers or padding so follow-on plant doesn’t damage it.
# How should we deal with an unexpected service strike or near miss?
/> Stop work, make the area safe, and keep people clear. Notify the utility provider via the agreed emergency route, record the event, and only restart after a review updates the permit, method, and brief so the same conditions don’t repeat.
