When running a cable underground — whether for power, motorway communications, lighting, or utilities — it’s essential to protect it from damage and make it easily identifiable. To achieve this, the cable must be run inside a duct. This guide explains how to choose the right materials for your application and how to install ducting safely.
Contents
1) Select the right material
Our ducting cable is available in both flexible and rigid options, including Twinwall HDPE, solid wall Polyethylene, and solid wall uPVC systems. The type of ducting you select depends on your application — for example:
- Flexible ducting is best for longer runs.
- Rigid ducting is better suited for shorter runs.
- Twinwall duct provides extra strength for use under paths and roads.
If you’re unsure which ducting you need, don’t hesitate to get in touch with our team of experts. We’ll identify which product best meets your specifications.
2) Select the right colour
Choosing the correct duct colour ensures quick identification during installation or maintenance. Here’s a quick guide to typical duct colours and their applications:
- Electricity – Black
- CCTV – Green
- Water – Blue
- Gas – Yellow
- Motorway Communication – Purple
- Street Lighting – Orange
- Street Lighting (Scotland) – Purple
- Traffic Signals – Orange
- Telecommunications (BT) – Grey
3) Make sure it meets industry standards
Depending on its application, ducting may need to meet specific certifications. Always check this when purchasing from your supplier. Our ducting is manufactured to the highest quality and complies with industry standards, including:
- BBA certification (for highways)
- ENATS 12/24 Issue 2007/8 (C2 Application)
Contact our team for guidance on the correct certification for your project.
4) Install the ducting safely
When installing ducting, follow best practices:
- Use as few bends as possible.
- Lay ducting along a clear route (e.g. a path or patio).
- Install at the recommended depths:
- Cable TV and communications – 250–350mm
- Electricity (LV) – 450mm
- Electricity (HV) – 450–1200mm
- Gas – 600–750mm
- Motorway communications – 450mm
- Street Lighting – 450–600mm
- Telecoms – 350mm
- Water – 750mm
Avoid placing the duct directly on stones that could cause damage — instead, lay it on a bed of sand. To make the duct easier to identify, use additional sharp sand or marker tape when backfilling. All ducts should include a draw rope after installation unless otherwise agreed locally.
5) Different ways to join the duct
The joining method depends on the ducting type:
- Twinwall duct: Uses plain ends; requires separate couplers.
- Flexible duct: Comes with a joiner attached at one end.
Always confirm with your supplier whether couplers are included or need to be purchased separately.
6) Access to ducting
Where access to the ducting cable is required, we recommend our duct access chambers, which are commonly used for electrical or telecoms cabling.
Our specialists can provide expert advice on ducting selection and installation. Call us today on 0121 351 3230.
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