Outdoor Network Cable Constructions: Aerial, Duct and Direct Burial

How aerial, ducted and direct burial routes change the jacket, core and mechanical protection of an outdoor network cable.

7 min read
  • Installation
  • Product Knowledge
Outdoor Network Cable Constructions: Aerial, Duct and Direct Burial

Most outdoor network cable problems are decided before the cable is ever pulled. The jacket, the core and the mechanical protection have to match the route the cable will live on, and that match matters more than the category printed on the reel.

Outdoor cable is not a single product. Between two projects, the same Cat5e, Cat6, Cat6a or Cat7 conductor pair can be built with different jackets, water blocking and mechanical protection. Those differences decide whether an installation still performs after years of sunlight, standing water, soil movement or rodent activity.

This guide covers the four routes behind most outdoor cable orders - aerial spans, ducts, direct burial and building entry - and the construction each one usually calls for.

Why the Route Decides the Construction

Sunlight, standing water, soil, vehicle loading and span load all act on the cable from the outside. The category sets the transmission performance of the copper; it says nothing about whether the cable survives the route it is installed on.

That is why an outdoor quotation normally starts from the route and the conditions around it rather than from a catalogue part number. Two projects in the same city can use the same Cat6 conductor and need completely different jackets and cores.

Aerial Spans

Aerial cable runs between poles, or between a pole and a building. It can be supplied with an integrated messenger for self-supporting spans, or without one where it will be lashed to an existing support.

The variables that matter are span length, the sag the route allows, and how much permanent sunlight the jacket will see. A construction that carries its own weight is a different product from one laid inside a duct.

  • Integrated messenger for self-supporting spans
  • Jacket strength matched to the span and the sag allowed
  • UV-stabilized PE jacket where the run sits in permanent sunlight

Duct and Conduit

Ducted routes are the most protected option. The cable is pulled through an underground duct, pipe or trenchless crossing, so it avoids direct soil contact and can be replaced without reopening the whole route.

Protection from soil does not remove the need for the right jacket. Ducts can hold standing water and condensation, and on long pulls the limiting factors become pull tension and bend radius rather than sunlight or rodent damage.

Direct Burial

Direct burial places the cable in a trench with no duct around it, so the construction carries all of the protection. The cable is normally specified with a water-blocked or gel-filled core, and with armor where soil, stone or vehicle loading can reach it.

  • Water-blocked or gel-filled core for standing water and condensation
  • Armor where soil, stone or vehicle loading can reach the cable
  • Burial depth, soil conditions and other services confirmed against your project drawings

Building Entry and Indoor Handover

Most outdoor runs finish at a building. The entry point is where outside plant cable hands over to the indoor network, and it is also where the two product families stop being interchangeable.

Outdoor PE jackets are not rated for flame and smoke the way indoor jackets are. For riser and plenum spaces, indoor-rated cable is used instead, even though an outdoor construction can physically be run indoors.

Construction Options at a Glance

Route, exposure and the construction that normally follows
RouteWhat It Has To SurviveTypical Construction
Aerial spanSpan load, wind, permanent sunlightUV-stabilized PE jacket with integrated messenger, or a lashing support
Duct or conduitStanding water, condensation, pull tensionPE jacket with a water-blocked core
Direct burialSoil, stone, rodent and vehicle loadingWater-blocked or gel-filled core, armor where required
Building entryHandover to the indoor networkOutdoor construction to the entry point, indoor-rated cable inside

What to Send with an Outdoor Cable Enquiry

A quotation can be built from a short list of details, and none of them need to be final. The route is the most useful input, because it narrows the construction fastest.

  • Installation route - aerial, duct, direct burial or building exterior
  • Cable category and the link speed the project has to carry
  • Any construction you have already specified, or the conditions we should design against
  • Total metres required and the reel length you want to pull from
  • Destination market, so certificates, test reports and packaging match your market or tender

Need the Right Cable Specification for Your Project?

Send us your required category, shielding, conductor, jacket, quantity, packaging, or target specification. Our team can help match the cable construction to your project requirements.

Our export team replies within 24 hours with pricing, lead time, and sample options.