Service strikes are still catching sites out across housing, civils and refurbishment, even when a “permit to dig” is in place. The paperwork on its own won’t stop a bucket clipping an LV cable or a post auger finding a gas main. Permits work when they knit together surveys, markings, supervised digging rules and a clear stop-work trigger. Treat the permit as a live control, not a gate stamp.
TL;DR
/>
– A permit to dig only works if it’s tied to current service plans, on-the-ground markings and proofing trial holes.
– Scanning, marking and supervision are non-negotiable; suspend the permit the moment conditions change.
– Keep rules simple: prove first, dig by hand around services, control plant, brief every shift.
– Close out properly with as-builts and lessons so the next hole isn’t a fresh risk.
The controls playbook for breaking ground without hitting services
# Stage 1: Define the scope and interfaces before you touch the ground
/> Lock down exactly where and how the ground will be broken: trench lines, post holes, trial pits, saw cuts or piling pre-augers. Agree boundaries with temporary works, traffic routes and adjacent trades so your dig doesn’t wander into new risk. Capture this in the RAMS and reference it on the permit. If the activity changes (different plant, deeper dig, shift to nights), the permit must be revalidated.
# Stage 2: Gather utility information and make it usable
/> Collect statutory utility plans, previous survey data and any as-builts from earlier phases. Treat paper plans as guidance, not gospel; they age fast and depths are rarely reliable. Convert what you have into a simple mark-up: service corridors shaded on the ground plan, with obvious “no-pin” and “hand-dig” zones. Keep a laminated copy at the workface alongside the permit.
# Stage 3: Scan, mark and prove on the ground
/> Use competent operators to scan with locator and signal generator; consider GPR where congested or uncertain. Mark findings clearly with paint and flags, showing service type and alignment, and record photos with date and grid reference. Prove positions with hand-excavated trial holes at crossings and tie-points. The permit shouldn’t go live until the supervisor can point to markings and trial holes and say, “we’ve proved it.”
# Stage 4: Set excavation rules that people can follow
/> Write simple, visible rules into the permit: hand-dig within a set distance of marked services, use insulated tools, no mechanical excavation until services are positively identified and exposed, and protect exposed services with timber and signage. Control plant with a banksman and defined approach angles to avoid slewing over service corridors. Maintain exclusion zones for pedestrians and non-essential trades, and post clear “permit area” boundaries.
# Stage 5: Brief, supervise and hold the stop-work line
/> Brief the crew at the workface at the start of each shift; show them the markings, photos and trial holes, not just the paperwork. Nominate one supervisor to hold the pen on the permit and the authority to stop; if they leave site, the permit is suspended until another competent person takes over. If rain floods the area, if markings are scuffed off, or if the route changes by even a metre, pause and re-check before you restart.
# Stage 6: Record what you find and close out cleanly
/> Update the mark-up with any deviations discovered, and capture as-built positions if services are exposed or rerouted. Photograph and file the final state before you backfill. Close the permit at shift end; don’t roll it silently into tomorrow. Feed any lessons into the next dig so you aren’t learning the same thing twice.
Scenario: near-miss on a public realm refurbishment
/> A small civils gang is installing bollards along a pedestrianised high street under night-time traffic management. Plans suggest telecoms run on the shopfront side, so the foreman sets a line 600 mm from the kerb. The locator can’t get a clear trace due to interference from nearby lighting columns, but the markings are sprayed anyway to keep the programme. On the second hole the auger grinds to a halt; a dull thud and a faint smell of gas send the team backwards. The supervisor hits stop and calls the gas emergency number; it turns out the low-pressure main jogs unexpectedly across the footway at the exact bollard location. No ignition, but the road closure overruns and nearby units lose supply. The review finds the permit was issued without trial holes and the scanning results weren’t challenged.
Actions this week to strengthen permits before you break ground
/>
– Collate all service info for live and upcoming digs into one clear plan, with shaded corridors and simple legends everyone understands.
– Walk the route with the locator operator and the supervisor, agree where trial holes are needed, and take date-stamped photos of markings.
– Prove at least one crossing per service with hand-dug holes before allowing plant to excavate; capture depths as guidance only.
– Ring-fence the dig zone with barriers and signage that match the permit map; keep non-essential trades out of the line.
– Nominate a single permit-holder per shift and empower them to pause work the moment markings are lost, conditions change or uncertainty creeps in.
– Stage insulated tools, timber protection and temporary support materials at the workface so crews don’t improvise.
Common mistakes
# Relying on paper plans as exact positions
/> Utility drawings are often out of date or indicative; depths and offsets vary. Use them to target scans and trial holes, not to greenlight digging.
# Scanning once and assuming it still applies days later
/> Weather, site clutter and plant movement can change what you can detect. Re-scan after layout changes, heavy rain or when markings are damaged.
# Permits issued from the cabin with no walkdown
/> If the issuer hasn’t stood over the line with the crew, the permit is just paper. Walk the route, point out markings and agree hold points.
# Letting the dig creep beyond the permitted area
/> Small route changes can cross unknown services. Redraw and re-brief the permit area before any deviation, even to “just get around that post.”
Bottom line: prove first, then dig with discipline
/> Permits to dig work when they knit desk information to ground truth with visible markings, trial holes and a supervisor who isn’t afraid to stop. Keep the permit live, local and linked to what crews can actually see. Expect closer scrutiny of service avoidance where programmes are tight and night works are common. The sharp questions for your next briefing: What have we proved, who can stop us, and what changes would force a re-check?
FAQ
# When should a permit to dig be used on a UK site?
/> Use a permit whenever you plan to penetrate the ground or slabs where buried services may exist, including small tasks like sign posts, fencing and trial pits. Good practice is to treat any ground disturbance as permit-controlled unless a competent person can rule out services with evidence.
# Who should issue and hold the permit to dig?
/> A competent supervisor who understands utility plans, scanning outputs and the method of excavation should issue and hold it. One named person per shift should have authority to pause work if uncertainty arises, with a clear handover if that person leaves site.
# What’s the minimum I should expect before allowing mechanical excavation?
/> You should see current service information, on-the-ground markings from a recent scan, and at least initial hand-dug proofing at key crossings. Mechanical excavation should only proceed where services are positively identified and protected, and safe stand-off practices are briefed and enforced.
# How do we manage permits when night shifts or multiple gangs are involved?
/> Keep permits shift-specific and area-specific, with a fresh briefing at the start of each shift. Coordinate between gangs so markings are protected, boundaries are respected and one supervisor controls each live permit zone.
# What should trigger suspension of a live permit?
/> Loss of markings, conflicting scan results, change in scope or plant, worsening ground or weather conditions, or discovery of uncharted services should all trigger a pause. Suspension isn’t failure; it’s a control that prevents a strike while you revalidate the safe system of work.
