DIY GUIDE · ELECTRICAL

How to run an Ethernet cable and fit a data socket yourself
A day for one run. £28–£37 for a data socket at each end and a tester; bulk cable on top.

Plan the route, keep clear of power cables, terminate both ends to the same colour code, then test.

DIFFICULTY
Moderate
part of the job only
TIME
A day for one run
the route and the drilling take longest; terminating both ends takes an hour
MATERIALS
£28–£37
two data sockets with surface boxes, one sold with a punch-down tool, and a basic tester
A PRO CHARGES
£60–£900
typically £300
  • Every step, start to finish
  • Checked October 2026 — sources at the end
  • Honest about when to call a pro

FIRST, THE HONEST ANSWER

Do it yourself, or get a electrician?

Do it yourself if…

  • You want one or two cables from the router to rooms in the same house
  • There is a route along skirting, through a floor void or a loft that you can reach
  • You can drill holes through floors and stud walls and keep clear of pipes and cables
  • You are happy to terminate small conductors precisely, following a colour code

Get a pro if…

  • The route means chasing into plaster or brick, or into a wall shared with a neighbour
  • You need a new mains socket for the router, a switch or a powered access point
  • The run passes through a fire-separating wall or floor, such as between a garage and the house or between flats
  • You need many outlets, a patch panel and certified testing

Safety first

  • Before drilling or cutting, find the mains cables. They run vertically and horizontally from switches and sockets, and under floors between joists. HSE's electrical guidance is to know where live conductors are and keep away from them; use a detector and, if in doubt, isolate the circuit.
  • Keep data cables separate from power cables. Running Cat6 tightly alongside mains cable in the same clip or notch invites interference and puts two systems where a single drill hole can damage both.
  • Lifting floorboards exposes pipes, cables and sometimes old lagging. HSE lists pipe lagging and boards among places asbestos may be found in buildings from before 2000; if you find anything that looks like it, stop.
  • In a loft, kneel on boards across the joists, never on the plasterboard between them. HSE's ladder guidance applies to the loft ladder too.
  • Drill joists only near their middle depth and not too close to the bearing ends; notching the top edge weakens the floor. If a run would need more than small holes, ask a builder.

Stop here: Stop here: the mains wiring, separating walls and fire barriers

A data cable carries no mains voltage, but anything touching the mains wiring does: a new socket or circuit for network equipment is electrical installation work, notifiable in England under Part P of the Building Regulations when it is a new circuit; Wales applies its own Approved Document P, never exempting kitchens, bathrooms or outdoors; Scotland works to building standard 4.5, and there electrical work that adversely affects a separating wall, such as recessed sockets, needs a building warrant in all homes; Northern Ireland has no Part P-style notification, but the work still needs a competent electrician. Chasing or cutting into a wall shared with a neighbour can fall under the party wall rules in England and Wales, and breaking through a fire-separating wall or floor must be fire-stopped to the building regulations' fire safety requirements in every nation. How to hire a data cabling installer →

MATERIALCOVERAGEFOR THIS JOB
Cat6 solid-core cableSolid copper, not copper-clad aluminium; LSZH indoorsThe route length plus a metre at each end
Cat6 keystone jacksTo match the cableOne per end, plus a spare
Faceplates and surface boxesSingle or double, to suit the number of cablesOne per end
Cable clipsSized for the cable diameterOne every half metre or so on surface runs

How much cable

Cable = the measured route + 1 m at each end for terminating and slack + 10% for detours. A 14 m route needs 14 + 2 + 1.4 = 17.4 m; a 20 m length will do.

Measure along the actual route — up and down walls, round doors, across the loft — not straight across the floor plan.

Cat6 solid-core cable for fixed runs

Use solid-core Cat6 for cable in walls, floors and lofts; stranded patch cable is for the short leads between socket and device. The Cat6 datasheet we checked describes a 23 AWG solid copper cable about 6.4 mm across, rated for a 90 m permanent link, so any run inside a house is well within range. Avoid copper-clad aluminium cable sold as Cat6; it is cheaper because it is not solid copper and it performs and terminates badly.

LSZH or PVC sheath

Low smoke zero halogen sheath gives off less toxic smoke in a fire. It is a sensible choice indoors, especially where cable runs through escape routes such as halls and stairs.

Keystone jacks and faceplates

A keystone jack is the socket module the cable is terminated onto; it clips into a faceplate. Toolless jacks close a cap over the conductors; punch-down jacks need a small tool that pushes each conductor into a slot. Buy Cat6 jacks to match Cat6 cable, and faceplates that fit standard back boxes or surface boxes.

One colour code at both ends

Each jack is marked with two colour codes, T568A and T568B. It does not matter which you use as long as both ends of the same cable use the same one. Pick one, write it down and stick to it.

A cable tester

A basic tester plugs into each end and shows whether all eight conductors connect in order. It catches a crossed pair or an unconnected conductor before you blame the router. It does not certify performance, but for a home link it is enough.

Surface or flush boxes

A surface box screws onto the wall with no cutting. A flush box sinks into the wall and needs a hole cut in plaster or plasterboard. Surface boxes are the householder's friend: no chasing, no dust and no risk to cables in the wall.

Buy one more jack than you need; a mis-terminated jack is easier to replace than to rework.
Label both ends of every cable before you pull it.

THE PART THAT DECIDES THE FINISH

Before you start — the route you have

The route decides everything. Walk it from the router to the far socket and match it to one of these.

Along skirting and architrave

The simplest route; no floors lifted.

  1. Plan the run along the top of the skirting, away from where sockets and their cables are
  2. Use small cable clips sized for the cable, every so often and at every turn
  3. Keep bends gentle; the datasheet we checked gives a minimum bend radius of four times the cable's diameter
  4. Paint the cable to match the skirting afterwards if it shows
Under a suspended timber floor

Floorboards over joists; common on ground floors of older houses and on upper floors.

  1. Lift a board at each end of the run, checking for pipes and cables first
  2. Run the cable alongside the joists where possible, clipped to the side of a joist
  3. Where you must cross joists, drill small holes near the middle of the joist's depth
  4. Keep the cable away from heating pipes and from mains cables in the same void
Through the loft and down

From an upstairs router across the loft to a bedroom.

  1. Work from boards across the joists; never step on the ceiling between them
  2. Lay the cable over the insulation, not buried under it, and away from downlight fittings
  3. Drop it down inside a stud wall or alongside a boxed-in pipe run
  4. Keep the cable clear of mains cables running to ceiling roses
Through a solid or shared wall

Brick, block, or a wall between two homes.

  1. One small hole through an internal brick wall is usually fine; check for cables first
  2. Do not chase or drill into a wall you share with a neighbour without considering the party wall rules
  3. Do not break through a fire-separating wall, such as between an integral garage and the house
  4. These routes are for an installer if anything more than one sealed hole is needed

THE JOB

How to run and terminate the cable

  1. Set up: plan the route and check for cables

    1 hr

    Walk the route from the router to the far socket and pick the case from the cards above. Mark where each socket will go. Sweep every drilling point and every floorboard you will lift with a cable and pipe detector. Measure the route and cut nothing yet.

    • Put the router end near the router and a power socket, not across the room
    • Plan sockets away from mains sockets by a little, not directly above or below them
    • Photograph under each board you lift before running anything

    Mistake to avoid: Drilling where the detector was not used. A mains cable under a floorboard or behind a skirting is easy to hit and expensive to repair.

  2. Prepare the route

    1 hr

    This is the prep from your card above. Lift the boards you need, drill the joist or wall holes, fit surface boxes at each end, and run a draw wire through any void the cable must cross. Clear sharp edges and nails from the path so the sheath is not cut as it is pulled.

    • Drill joist holes near the middle of their depth, not near the top or bottom edge
    • Keep holes as small as the cable needs
    • Fit grommets or smooth the edges where the cable passes through metal or sharp wood

    Mistake to avoid: Notching the top of joists to lay the cable in. Notches weaken the floor and leave the cable where the next floorboard nail will find it.

  3. Pull the cable

    45 min

    Label both ends of the cable before you start. Tape one end to the draw wire and pull it through steadily, with someone feeding it from the reel so it does not kink or twist. Do not yank it round corners. The datasheet we checked lists a maximum pulling force of 11.5 kg, which is easily exceeded by a hard pull on a snag.

    • Feed from the reel without letting it twist into loops
    • Leave a metre spare at each end
    • Keep it clear of mains cables in the same void

    Mistake to avoid: Hauling the cable through a tight hole until it moves. Over-pulled cable stretches its pairs and the link fails or runs slowly.

  4. Clip and dress the run

    45 min

    Clip the cable along its route with clips sized for it, without crushing it. Keep bends gentle, no tighter than four times the cable's diameter by the datasheet. Keep a little separation from mains cables wherever they run alongside, and cross them at right angles where they must cross.

    • Clips snug, not squeezing the sheath
    • No tight kinks behind furniture or round door frames
    • Replace the floorboards with screws, so they can come up again without damage

    Mistake to avoid: Bundling data cable tightly with mains cables under one clip. It is untidy, it can pick up interference, and one nail now damages both.

  5. Strip and prepare the ends

    15 min

    At each box, cut the cable leaving a little slack folded inside. Strip a short length of outer sheath, just enough to reach the jack, with a rotary stripper, taking care not to nick the pairs. Cut off the central spline and any pull thread. Keep each pair twisted as close to the jack as possible.

    • Score the sheath lightly and flex it to break it, rather than cutting deep
    • Check no conductor's insulation is nicked
    • Untwist only what is needed to reach each slot

    Mistake to avoid: Untwisting the pairs back to the sheath. The twist is what makes the cable work at speed; untwisted conductors near the jack lose performance.

  6. Terminate the keystone jacks

    30 min

    Lay each conductor into the slot of the same colour for your chosen code, T568A or T568B, as printed on the jack. On a punch-down jack, push each conductor home with the punch-down tool, cutter side to the outside, so it seats and trims in one action. On a toolless jack, lay the conductors in the cap and close it firmly. Do the other end with exactly the same code.

    • Same code at both ends; write it inside the faceplate
    • Keep the sheath as close to the jack as it will go
    • Check every conductor is fully seated, with no copper showing

    Mistake to avoid: Using T568A at one end and T568B at the other. The link then crosses two pairs and either fails or runs at a fraction of its speed.

  7. Fit the faceplates

    15 min

    Clip each jack into its faceplate, fold the slack cable gently into the box without sharp bends, and screw the faceplate on. Label each socket with the room or the number of the other end.

    • Do not crush the cable behind the faceplate
    • Label both ends the same, such as 'Lounge 1'
    • Fit blanking modules in any unused faceplate holes

    Mistake to avoid: Forcing a tight fold of cable behind a shallow faceplate. The bend kinks the pairs, and the link that tested fine on the floor fails once fitted.

  8. Test the link

    15 min

    Plug the tester's main unit into one socket and the remote into the other with two short patch leads. Run the test: all eight lights should go in order, one to eight. Then connect the router and the device, and check the device shows a gigabit connection.

    • A light out of order means a crossed pair; a missing light means a conductor not seated
    • Rework the jack at the end where the fault is, not both
    • Use good patch leads; a cheap lead fails more often than the fixed cable

    Mistake to avoid: Skipping the test because the device connects. A link with one bad pair can connect at a slower speed and look fine.

The mistakes that show

  • Using different colour codes at each end
  • Untwisting the pairs too far at the jack
  • Over-pulling the cable or bending it tighter than its rating
  • Running data cable tight alongside mains cable
  • Buying copper-clad aluminium cable sold as Cat6

Stop here and get a network cabling installer

  • The route needs chasing into plaster or brick, or into a wall shared with a neighbour
  • A new mains socket, spur or circuit is needed for the router or equipment
  • The run crosses a fire-separating wall or floor
  • You need many outlets, a patch panel or certified test results
How to hire a data cabling installer →

Ethernet link shows 100 Mbps instead of gigabitOne pair is not connected or is crossed. Test with a cable tester, and reterminate the jack at the faulty end.
Cable tester lights out of orderA pair is crossed at one end, or the codes differ. Check both jacks use the same code, T568A or T568B, and reterminate.
No connection at allA conductor is not seated, or the patch lead is faulty. Try another patch lead, then retest the fixed link.
Link drops intermittentlyA damaged cable, a loose jack, or interference from a mains cable run alongside. Check the jacks, inspect the route, and separate the run from power cables.
Faceplate will not sit flatToo much slack or a tight fold behind it. Use a deeper box or lay the slack in a gentle loop.
Conductor will not stay in the slotThe conductor is stranded, not solid, or the wrong gauge for the jack. Use solid-core cable and jacks rated for it.
Cable sheath cut during the pullA sharp edge or nail on the route. Find it, clear it, and replace the cable if the pairs are damaged.
Slow speeds despite a good testThe device, the router port or the patch leads are the limit. Check each with a known good lead.

WHAT YOU SAVE

What it costs to do it yourself

Cat6 data socket with surface box and punch-down tool, two£20
Basic cable tester£8–£17
Bulk Cat6 cable, 305 m reel£43
Total, one run without the cable£28–£37
DIY total£28–£37
A data cabling installer charges per job
LOW
£60
TYPICAL
£300
HIGH
£900
Data & Network Cabling price guide →

Guide prices compiled by the Locufy team from published Irish and UK provider price lists and 2026/27 cost guides. Updated 2026.

A network cabling installer's guide price per job covers several outlets and testing. One home run costs the jacks, two faceplates, a cheap tool and tester, and the cable.

RATHER NOT?

Data cabling installers near you, with prices shown

The ones who cover your area, nearest first, with one score from every review. No account needed to look.

Or post the job free and let them come to you.

Label and record

Label both ends of every cable and keep a sketch of the route with the colour code written on it.

Protect the run

Note where cable runs under floorboards so nobody nails through it when the boards next come up.

Dispose of the offcuts

Offcuts of network cable are copper and go to the cable or metals recycling at your council's household waste recycling centre; old routers and switches are electrical waste and go in the electrical recycling there. Find your centre on the council website or the recycling pages for your nation.

Keep the spares

Keep a spare jack, a faceplate and the tester together for the next run or a repair.

Running an Ethernet cable and fitting a data socket: questions people ask

Yes. A network cable carries no mains voltage. Plan the route, keep clear of mains cables and pipes, terminate both ends to the same colour code, and test it.

Cat6 solid-core is a good choice for home runs: it handles gigabit easily over far longer runs than a house needs. Avoid copper-clad aluminium cable.

Either, as long as both ends of the same cable match. Write the one you used inside the faceplate.

Keep them apart where you can and cross at right angles. Bundling them together can cause interference, and means one drill hole can damage both.

Not for the data cable itself. A new mains socket or circuit for equipment is electrical work with its own rules in each nation, and cutting through fire-separating walls or walls shared with neighbours brings other rules.

Locufy's UK price guide puts data and network cabling at £60–£900 per job, typically £300 — the same three figures as the strip at the top of this page.

MORE GUIDES

More DIY guides

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All 90 DIY guides →How to hire a data cabling installer →Data & Network Cabling price guide →Data cabling installers on Locufy →

Sources — checked October 2026

  1. Multicomp Pro — Cat6 U/UTP LSZH cable datasheet: construction, bend radius, pulling force, link length
  2. HSE — electrical safety: frequently asked questions
  3. HSE — asbestos: frequently asked questions (boards and lagging, buildings before 2000)
  4. HSE — ladders and stepladders
  5. gov.uk — Approved Document P: electrical safety in dwellings (England)
  6. gov.wales — building regulations: electrics
  7. gov.scot — Regulation of electricians in Scotland: when a building warrant is needed, including separating walls
  8. gov.scot — Building Standards Technical Handbook 2022 (domestic), standard 4.5 electrical safety
  9. gov.uk — recycling collections: find your council (England and Wales)
  10. mygov.scot — find your council's recycling centre (Scotland)
  11. nidirect — recycling and reusing (Northern Ireland)
  12. B&Q — price check: Cat6 cable
  13. B&Q — price check: RJ45 keystone jacks
  14. B&Q — price check: data faceplates
  15. B&Q — price check: punch-down tools
  16. B&Q — price check: network cable testers