Running a cable to the shed: when ethernet beats every wireless fix

Every wireless link to a shed is a negotiation with the environment. Rain fade, foliage growing into the path, antennas knocked out of alignment, interference from every other radio in range — each one taxes your speed and reliability. A cable in the ground negotiates with nothing. No weather, no alignment, no interference, no shared spectrum. It runs at full speed on the worst day of the year, and it keeps doing so after you’ve forgotten it exists.

The performance gap matters less than the reliability gap. A decent wireless bridge can post good speeds on a clear day. The cable posts the same number every day, and it carries power-over-ethernet for a camera or access point at the shed end as a bonus.

Two ways to put ethernet underground, and one of them is clearly better.

Conduit first. Bury electrical/communications conduit and pull the cable through it. The conduit protects the cable from soil, water and shovels, and — the real win — lets you replace or add cables later without digging again. Pull a draw wire through with the first cable and future-you will be grateful. Oversize the conduit; it costs little more and you will want the space.

Direct-burial cable second. If you’re trenching once and never again, use cable actually rated for direct burial — gel-filled or flooded outdoor cable built to survive wet soil. It works, but a damaged run means a new trench.

Indoor cable in dirt: never. Ordinary indoor ethernet cable in the ground fails. The jacket isn’t built for moisture, and water wicks along the cable into your connectors. It might survive a year or two, then you’re diagnosing a “network problem” that’s actually a rotted cable.

Ethernet over copper has a hard design limit of roughly 100 metres end to end — wall socket to wall socket, patch leads included. Inside that, you’re fine. Past it, links get flaky in ways that are miserable to diagnose.

The answer for longer runs is fibre. Fibre between buildings sounds exotic and isn’t anymore: a pre-terminated outdoor fibre lead and a small media converter or switch with a fibre port at each end. Fibre carries a second advantage worth naming on any rural block: it’s glass, not metal. It cannot conduct a lightning-induced surge from one building into the other. For long runs, or for sheds with expensive gear inside, fibre is often the right call even under 100 metres.

A buried copper cable electrically joins two buildings. Nearby lightning — not even a direct strike — can induce a surge along that copper, and differences in earth potential between the buildings can push current through it during a fault. Either can cook the network gear at both ends.

If you run copper, fit an ethernet surge protector where the cable enters each building, and understand that doing surge protection properly involves earthing and bonding — which is licensed-electrician territory in Australia, as is any mains work at the shed. There’s also a compliance angle on fixed network cabling itself: Australia has cabling-provider rules that can require a registered cabler for fixed cabling work, so check where your job sits before you DIY the terminations. If all that sounds like more than you signed up for, that’s another quiet argument for fibre, which sidesteps the surge problem entirely.

Before any trench, check what’s already in the ground. Australia has a free national referral service — Before You Dig Australia — that tells you where registered services run on and near your property. Private runs (your own power to the shed, irrigation, septic lines) won’t be on anyone’s map, so think about what past owners buried.

Practicalities that save grief: dig once and dig deep enough that a garden fork never finds the conduit; lay marker tape above the run; take photos with a tape measure in frame before you backfill; and keep the run away from mains power trenches or cross them at right angles. A hired trencher turns a weekend of digging into an hour.

The cable isn’t always the answer. Skip it when:

• You’re renting. You can’t trench someone else’s land, and you take nothing with you when you leave. Use a wireless option instead.
• The ground says no. Solid rock or sandstone shelf between house and shed turns a cheap trench into an expensive one. Price the trenching honestly before committing.
• The distance is extreme. At many hundreds of metres, trenching cost climbs while a good point-to-point wireless link with clear line of sight gets more attractive — that’s the territory of our sister service Long Range WiFi, and the chooser covers the trade-off.
• The need is temporary. A shed you’ll use for one season doesn’t justify earthworks.

One buried cable outperforms every wireless fix — no weather, no alignment, no interference, same speed every day. Put it in conduit with a draw wire, or use genuine direct-burial cable; never indoor cable in dirt. Copper tops out around 100 metres and wants surge protection at both ends; fibre goes further and can’t carry a lightning surge between buildings. Check Before You Dig Australia before trenching, and skip the whole exercise if you’re renting, on rock, or only need the link for a season.

General guidance only — distances, ground conditions and cabling rules vary, so verify against your own site and current regulations before digging or buying gear.