Cable Conduit, Trunking & Routing

To conceal cable conduit trunking into a solid wall you need to follow some basic steps. Firstly you must make a channel in the wall ensuring that it is 6mm wider and 3mm deeper than the conduit you are using. Then cut the conduit to the required length and feed your cable through. This can now be fixed within the channelling using any self-adhesive backing, conduit clips or nails before plastering the wall for a clean neat finish.

Determining cable conduit size

To calculate the conduit size you require, you must first multiply the cross-sectional area of each cable by the appropriate factor, the total factor for each of your cables must not exceed the capacity factor recommended for each conduit diameter.

Conduit Diameter (mm)            Capacity Factor

·         16mm                                           290

·         20mm                                           460

·         25mm                                           800

·         32mm                                           1400

How many cables fit into conduit and trunking?

The recommended maximum fill percentage of a conduit containing just 1 wire is 53%, for 2 wires, the maximum percentage is 31% and if the conduit contains 3 or wires, the maximum percentage is 40%. The size of the conduit you require can all be checked by calculating the cross-sectional area of the wires that will be contained within the conduit.

When incorporating bends within the conduit, it is recommended that 15% is subtracted from the maximum cross-sectional area being used. You should also avoid using 2 or more 90° bends in a single section of conduit.

Calibrate new and existing equipment
Get a quote online, quick and easy
Return online within 30 days

Guides & Articles


Our cable ties guide looks at the different types that are available on the market and the differences between them, with some handy tips on using them


Not all Ethernet cable is the same. What makes Cat 6 different to other network cables? Our guide looks at the differences helping you decide

Related Products
A range of Conduit, Fittings and Accessories manufactured ...
A range of Conduit, Fittings and Accessories manufactured from high grade stainless steel. These products are able to operate in many aggressive environments including conditions experienced offshore. They are ideal for applications in the food, brewing, dairy, pharmaceutical and chemical industries or anywhere that requires high pressure washdowns. Their aesthetically ...
The Legrand flush mounted adaptable box is designed ...
The Legrand flush mounted adaptable box is designed to be mounted onto plasterboard or plywood and is supplied with a cover and screws. This box is known for providing maximum volume for multiple conductors and connectors. It serves as the common junction point for splices of electrical wires where they ...
Resistance to glow wire test: 750 °COperating temperature: ...
Resistance to glow wire test: 750 °COperating temperature: – 25 °C to + 40 °CInterchangeable membrane glands with direct entryCaptive cover with clippable tie between box and cover except boxes 310 x 240 and 360 x 270Cover opens/closes with a 1/4 turn of a regular screwdriverCan be associated with Nylbloc ...
BS4568 Part 2 product finish classification.,Class 2 - ...
BS4568 Part 2 product finish classification.,Class 2 - Black enamelled inside and outside.,Class 3 - Pre-galvanised sheet steel.,Class 4 - Hot dipped galvanised inside and outside. Lids are secured by M5 x 8mm mushroom head screws.