Skill: Loop, Fit Safety, Entry, and Exit Induction Loops in Driveways
Skill level: 2
Safety
Learning Objective
Understand how to correctly and safely locate, install, and test induction loops in tarmac or other driveway surfaces (gravel, pavers, etc.) for safety, entry, and exit functionality in gate automation systems.
1. Overview
Induction loops detect vehicles and are vital for:
Automatic gate entry and exit
Preventing gate closure on vehicles (safety)
Hands-free gate access
Improved reliability
❌ Poorly installed loops can cause malfunctions, false triggers, missed detections, and void warranties.
2. Tools & Materials Required
For Preformed Loops (gravel/pavers):
Preformed loop (3-turn, 20mm conduit)
Max 10m tail in flexible duct
Spade, trowel, breaker
Ducting & backfill materials
Traffic cones
Ohmmeter & megohmmeter
For Cut-In Loops (tarmac):
Floor saw with diamond blade
Loop cable
Bitumen (hot, not boiling)
Heat source & PPE (gloves, visor, extinguisher)
Scraper/flat blade
Blower/air gun
traffic cones
3. Before You Start (Design and Planning)
Confirm correct loop type (entry, exit, safety).
Ensure minimum 800mm clearance from moving gates/metal.
Keep loop within 10m of control box.
Entry/exit loops ~5m from gates (adjust for drive size).
Avoid locations where entry loops may trigger from road traffic.
Check ground type and reinstatement method (pavers, tarmac, gravel).
Agree final loop positions with customer and record in job notes.
4. Procedure
Installing Preformed Loops
Confirm loop location and trench line.
Dig trench 100mm deep for loop rectangle.
Lay loop flat and bury conduit.
Route twisted tail in ducting back to control box.
Ensure tail avoids moving metal.
Backfill, compact, and reinstate surface.
Cutting and Installing Loops in Tarmac
Hot bitumen burns, take safety precautions, keep powder type fire extiguisher close by.
Mark out 2m x 1m rectangle with 45° corners.
Saw cut ~50mm deep, go around twice.
Clean slot with air gun.
Pull 3 turns of cable, leave equal tails (e.g. 5m each).
Route back to control box, twist tails (approx 10 turns/foot with drill).
Push cable fully into slot with blunt tool.
Fill slot with hot bitumen, allow to cool, scrape excess.
5. Best Practices
Always test preformed loops before covering.
Record test results in job sheet or Clik for warranty.
Photograph installation and reinstatement.
Use correct depth and spacing — too shallow = weak detection.
Keep reinstatement neat to avoid complaints.
Keep an eye on the bitumen burner, don't over heat bitumen.
6. Common Mistakes to Avoid
🚫 Loop too close to gates/metal = false triggers
🚫 Untwisted tails = signal interference
🚫 Bitumen overheated = cable damage
🚫 No testing before handover = warranty issues
🚫 Loop cut too shallow = weak signal
🚫 Entry loop triggers from road traffic
7. Safety Information
Relevant SSOW References:
SSOW-06: Manual Handling of Posts & Heavy Materials
SSOW-07: Safe Use of Power Tools & Cutting Equipment
SSOW-13: Working in Driveways and Vehicle Areas
SSOW-16: COSHH – Handling Fuels, Chemicals, and Bitumen
SSOW-18: Excavation and Use of CAT Scanner