Quick Answer: Indoor fibre pays when a run is long, when the route leaves the building, or when copper would create an earth loop. It carries 10 Gbit/s far beyond the 100 m that Cat 6a manages on a 500 MHz channel, and it ignores mains interference and conducted surge. What it does not do is terminate itself: a splicer and a loss tester cost more than a drum of copper, so below about 100 m Cat 6a usually wins on installed cost.
A home network is a copper network by default, because copper is cheap, the tooling is a crimp tool and every device has a socket. Fibre enters the argument at the two points copper cannot follow: distance past 100 m, and any route where the two ends must not share an electrical earth. Those two cases decide most domestic installations.
Where indoor fibre wins
The first win is distance. 10GBASE-T over Cat 6a reaches 100 m on a 500 MHz channel; multimode fibre carries the same rate several hundred metres and single-mode far more. In a large house that difference matters mostly for outbuildings, where the run leaves the main building.
Distance beyond copper
Cat 6 holds 10 Gbit/s to about 55 m and Cat 6a to 100 m, which covers most rooms. A garage, workshop or annexe often sits past that. Pre-terminated indoor fibre cable in a fixed length removes the jointing problem and pulls through a duct in one go.
Electrical isolation
Copper joins two earths. Between buildings that means a potential difference driving current through the screen, and a nearby lightning strike induces a surge that arrives at both ends. Fibre carries light only, so it breaks the loop. Where an outbuilding has its own supply, that isolation is worth more than the bandwidth.
Where it loses on cost
Fibre is cheap as glass and expensive as a joint. A fusion splicer, a cleaver and a power meter cost far more than a crimp tool, and a poor cleave shows up as loss rather than as a dead link. That is why the crossover point sits near 100 m.
Termination and connectors
Two routes exist: pre-terminated assemblies in fixed lengths, or field termination with a splice. Pre-terminated is the practical domestic choice, provided the length is ordered before the duct is sealed and the connectors are protected during the pull. Our fibre patch cords guide covers the connector types and polarity conventions that catch people out.
Media converters and power
Both ends need an optical port. A switch with an SFP slot is the tidy answer; a media converter is the cheap one, adding a box and a power supply at each end. Two converters and two sockets is often the point where the saving over copper disappears.
Weighing fibre against Cat 6a
Decide on the route first and the optics second. A run inside one building under 100 m is copper work, and a Cat 6a 10G cable on a 500 MHz channel already handles it; anything longer, or anything crossing to another structure, is fibre work. Bend radius is the other check: fibre dislikes a tight corner more than copper does, so allow a generous radius at every bend and never pull it around a right angle without a former.
| Criterion | Cat 6a copper | Indoor fibre |
|---|
| 10 Gbit/s reach | 100 m | Several hundred metres |
| Mains interference | Screening needed | Immune |
| Surge and earth loops | Copper path end to end | None |
| Field termination | Plug and test | Splice or pre-terminated |
| Typical use | Room drops | Risers and outbuildings |
Practical scenarios
- Situation: A studio 140 m from the house on the same supply. Run fibre in duct, because 10GBASE-T over Cat 6a stops at 100 m whatever the cable quality.
- Situation: A garage on its own supply where a copper link hums. Fibre removes the earth loop that a screened copper link would carry through its screen.
- Situation: A 60 m run to a top-floor bedroom. Cat 6a is cheaper and easier to terminate, and fibre only pays if 10 Gbit/s is certain and the duct is awkward.
- Situation: An 80 m pre-terminated assembly arrives with connector shells too fat for a 25 mm duct. Fit a pulling sock and check the shell diameter before ordering.
FAQ
Can fibre feed a normal laptop?
Only through a media converter or a switch with an optical port, because laptops carry copper Ethernet sockets. Fibre is a backbone choice, not a desktop one. Use it between switches or to a wireless access point with an SFP slot, and keep copper for the last few metres.
Is fibre affected by mains interference?
No. The signal is light inside a glass core, so electric fields from mains cable have nothing to couple into. That is why fibre can share a duct with power, subject to the separation and fire performance rules that apply to its jacket in that location.
Multimode or single-mode indoors?
Multimode is easier to connectorise and suits short links with inexpensive optics. Single-mode costs little more as cable and reaches much further, which matters for outbuildings. Under 300 m either works, so choose the type the switches at both ends already support.
