DIY GUIDE · ELECTRICAL · CHECKED OCTOBER 2026
How to run an Ethernet cable and fit a data socket yourself
A day. €16–€72 for a reel of Cat6, a data outlet kit and patch leads.
Plan the route, pull the cable without kinking it, terminate it in the right colour order, test it. Leave the mains, the board and the operator's equipment alone.
- 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 data points in another room, fed from the router or a switch beside it
- There is a practical route: under floorboards, through the attic, along skirtings or down a cupboard
- You are happy to drill through a wall or floor after checking for cables and pipes
- The router and its power socket stay where they are
Get a pro if…
- The route means chasing cable into plastered walls across the house
- You need a new mains socket near the router or at the far end
- You want a full structured cabling system with a patch panel and many outlets
- The cable would have to run outside, underground or to another building
Safety first
- Scan before every hole. Mains cables run in the same floors, walls and attics as your route; the HSA's electricity guidance treats contact with live parts as the danger to control.
- In the attic, stand only on boards or joists. The HSA's ladder guidance asks for three points of contact on the ladder up to the hatch.
- Wear gloves and a dust mask when moving attic insulation.
- Wear eye protection when drilling overhead or through masonry.
- If you drill into a mains cable, do not touch it. Switch off at the board from a dry place and call a Registered Electrical Contractor.
Stop here: Stop here: the mains, the board and anything outside
Data cable carries no mains power, but the moment the job needs a new socket, a new circuit or anything at the distribution board, it becomes restricted electrical work under Irish law, S.I. No. 264 of 2013, which only a Registered Electrical Contractor may carry out and certify; the CRU prosecutes unregistered restricted work. A cable run outside, underground or to an outbuilding is a danger without the right cable and protection, and is a job for a professional. Equipment your broadband operator installed belongs to the operator; leave it alone. How to hire a data cabling installer →
| MATERIAL | COVERAGE | FOR THIS JOB |
|---|---|---|
| Cat6 solid cable | Solid copper, sized for the run plus slack | One reel |
| Data outlet kit | Faceplate, Cat6 module and back box | One per end |
| Patch leads | Short Cat6 leads from the socket to the device and from the router to the socket | Two |
| Cable clips | Sized for the cable, not crushing it | A pack |
How much cable to buy
Cable = route length + rise and fall at each wall + slack at each end. A route of 14 m across the attic, two drops of 2.5 m, and 0.5 m spare at each socket needs 20 m, so a 25 m reel.
Measure the route with a tape or a length of string, add the vertical runs, and buy the next reel size up. A cable that falls short by a metre is useless.
Cat6 cable is the sensible choice for a new home run today. One maker's Cat6 sheet we read gives a frequency rating of 250 MHz and an outer diameter of 6.0 mm, with solid copper conductors, which is what makes it suitable for the fixed run between two sockets. Use solid-core cable for the run and flexible patch leads only at each end.
The same sheet gives a minimum bending radius during installation of more than eight times the outer diameter. On a 6 mm cable that means no bend tighter than about the curve of a coffee mug. Tight kinks, crushing under a clip and stepping on it all damage the twisted pairs inside.
If the run can go along skirtings and under doors, a long ready-made patch lead with plugs on both ends saves terminating anything. For a neat, permanent job, a socket at each end looks better and protects the cable.
Find where the socket will go, then work back to the router: up into the attic and down a wall, or under the floor and up behind a skirting. Avoid running alongside mains cables for long distances; cross them at right angles where you must.
The fibre or broadband box and its socket where the line comes into the house belong to your broadband operator. Plug into your own router or a switch, not into anything the operator installed.
THE PART THAT DECIDES THE FINISH
Before you start — the route you have
Walk the route from the router to the new socket. Match it to one of these and do its prep.
Through the attic and down a wall
Upstairs rooms, or a bungalow where the attic covers both ends.
- Check the attic for safe boarding along the route
- Find the top plate of the wall you will drop down, and check the cavity below is clear
- Scan the wall below for cables and pipes before drilling
- Lift insulation carefully and lay it back after
Under suspended timber floors
A ground floor with floorboards and a void below.
- Lift a board near each end and look along the void with a torch
- Check the direction of the joists; crossing them means drilling each one
- Drill joists only in the middle of their depth, never notch the top or bottom
- Look out for pipes and mains cables in the same void
Along skirtings and through one wall
Rooms next to each other, or a run where hiding the cable is not essential.
- Plan the cable along the top of the skirting or behind it
- Scan the wall at the drill point for cables and pipes
- Drill through the wall low, near the skirting, with a long masonry bit
- Use clips spaced along the skirting that hold without crushing the cable
Solid floors and plastered walls
Concrete floors and block walls with no void to use.
- Consider surface trunking along skirtings instead of chasing walls
- Do not chase a wall without knowing what is buried in it
- If a chase is unavoidable, that is a job for a professional
- A long patch lead along the skirting may be the simplest answer
THE JOB
How to run the cable and fit the socket
Plan and set up
30 minMark the socket positions at both ends and the route between them. Check at each drill point with the detector. Lay out the reel, tools, clips and outlet kits. Set up a stepladder for the attic hatch and boards to stand on up there.
- Fit the sockets at the same height as the room's power sockets
- Keep the router end near the router and its power
- Tell the household where you will be drilling
Mistake to avoid: Starting to drill before the route is planned end to end. You end up with holes that do not line up and a cable a metre short.
Do the prep for your route
30 minThis is the prep from the cards above: board the attic, lift floorboards at each end, find joist directions, scan each wall. Mark the drilling points clearly.
- Lift boards carefully at their screws or nails so they go back flat
- Photograph what is in the void before you start
- Put a light in the void to see further along
Mistake to avoid: Lifting floorboards without checking for pipes and cables underneath. A nail or screw through a pipe as you refit the board is a leak under the floor.
Drill the holes
45 minDrill through the top plate, the joists or the wall at the marked points, with the right bit, after checking each spot again with the detector. Keep holes in joists to the middle of their depth. Clean out dust so the cable is not snagged.
- Drill slightly larger than the cable so it slides through
- Use a long bit to reach without enlarging the opening
- Wear eye protection when drilling overhead
Mistake to avoid: Drilling through the bottom of a joist or notching its top. It weakens the floor.
Pull the cable
60 minFeed the cable from the reel, letting it turn freely so it does not twist. Use a draw wire or rods to pull it through voids, and guide it rather than yank it. Leave half a metre spare at each end.
- Tape the cable end smoothly to the draw wire so it will not catch
- Pull gently and steadily; have a helper feed it
- Keep bends gentle, inside the maker's bending radius
Mistake to avoid: Hauling the cable round a sharp edge or kinking it to get past a joist. The pairs inside deform and the link fails at speed.
Fix the cable along its route
30 minClip the cable along skirtings or joists at regular intervals with clips that hold it without squeezing it. Keep it off hot pipes and away from the mains cables where you can, crossing them squarely.
- Leave clips loose enough to slide the cable
- Do not staple through or squash the cable
- Lay it on top of attic insulation, not buried in it, if it may need moving
Mistake to avoid: Hammering cable clips tight. A crushed cable looks fine and performs badly.
Fit the back boxes
30 minFit the back box from the outlet kit at each end, surface-mounted or into a dry-lining wall, after checking behind with the detector. Feed the cable into the box through a grommet or knock-out.
- Keep the box level so the faceplate is straight
- Leave the spare cable coiled loosely in the box
- Fix surface boxes with screws suited to the wall
Mistake to avoid: Fitting the box tight to a power socket so the cables share a gap. Keep the data box a little apart.
Terminate the cable in the module
40 minStrip the outer sheath back only as far as the module needs. Keep each pair twisted right up to its contact. Lay each core in the slot shown by the module's colour code, using the same wiring scheme at both ends, and seat it with the punch-down tool or the module's own cap. Trim the excess.
- Use the same colour scheme, usually printed on the module, at both ends
- Untwist as little as possible
- Clip the module into the faceplate and fix the plate
Mistake to avoid: Untwisting the pairs a long way back. The cable then picks up interference and the link runs slowly.
Test the link
20 minPlug the tester's two halves into each socket, or into a patch lead at each, and run it. Every core should light in order. Then connect the router to one socket with a patch lead and your device to the other, and check the speed and that the link light shows the connection.
- Test before you put floorboards back
- If one core fails, reterminate that end
- Label each socket with where it goes
Mistake to avoid: Refitting floorboards and boxing before testing. A crossed pair at one end means opening everything again.
Connect the far end and the router end
20 minAt the router, plug a short patch lead from a spare port on the router or a small switch into the new socket. At the far end, plug the device into the socket with another lead. If the router has no spare port, a small network switch beside it adds more; plug the switch's own power supply into the existing socket the router uses or one next to it, never a new one you have added yourself. Check the device now gets its connection over the cable and not over Wi-Fi.
- Turn off Wi-Fi on the device briefly to prove the cable link works
- Keep patch leads short and tidy at the router
- Note which router port feeds which room
Mistake to avoid: Daisy-chaining extension leads to power a switch at the router. A crowded multi-plug behind the router is a fire risk; keep to the sockets that are already there.
Close up and tidy
30 minRefit floorboards with screws, keeping well clear of the cable, pipes and mains cables below. Lay attic insulation back. Clean up the dust and coil any spare patch leads neatly.
- Mark on the board where the cable runs underneath
- Screw boards down rather than nailing them
- Keep spare cable for a future repair
Mistake to avoid: Nailing floorboards back over the cable. One nail through it and the link fails.
The mistakes that show
- Drilling without scanning for mains cables and pipes
- Kinking or crushing the cable while pulling or clipping it
- Untwisting the pairs too far at the module
- Using different colour schemes at each end
- Closing up floors before testing the link
- Plugging into the broadband operator's own box
Stop here and get a Registered Electrical Contractor or a cabling installer
- A new mains socket is needed for the router or a device at the far end
- The route means chasing walls you cannot see inside
- The cable has to go outside, underground or to another building
- You have damaged a mains cable while drilling
| WHAT YOU SEE | WHY, AND THE FIX |
|---|---|
| Tester shows a core missing | A core is not seated in its contact. Reterminate that end, pushing the core fully into its slot. |
| Tester shows cores crossed | Different colour schemes at each end. Reterminate one end to match the other. |
| Link works but is slow | Pairs untwisted too far, a kinked cable, or an old patch lead. Reterminate with the twists kept, and change the patch leads. |
| No link light at all | The router port, a patch lead or the socket. Swap each patch lead first, then test the cable. |
| Link drops when a nearby appliance runs | The cable runs alongside a mains cable for a long way. Reroute it apart, crossing at right angles. |
| Cable will not reach the socket | The route was longer than measured. Use a socket at the short end and a joiner rated for Cat6, or run a new length. |
| Faceplate will not sit flat | Too much spare cable in the box. Coil it loosely and use a deeper box. |
| Drill hit something | Stop at once. If it is a mains cable, do not touch it; switch off at the board and call a Registered Electrical Contractor. If it is a pipe, turn off the water. |
WHAT YOU SAVE
What it costs to do it yourself
| Cat6 cable, 25 m or 50 m | €32.30–€52 |
|---|---|
| Cat6 single outlet kit, one per end | €12 each |
| Cat6 patch leads, 3 m to 10 m | €8–€16 |
| Total | €16–€72 |
| DIY total | €16–€72 |
Guide prices compiled by the Locufy team from published Irish and UK provider price lists and 2026/27 cost guides. Updated 2026.
The low figure is a single 10 m ready-made lead along the skirting. The high figure is a 25 m reel, an outlet kit at each end and two short patch leads, still a fraction of a professional install.
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.
Mark each socket with where its other end is. It saves confusion the next time you rearrange the router or the desk.
Keep the rest of the reel and a spare module. A pet chewing a patch lead or a damaged socket is a ten-minute fix.
Old network leads and broken modules are electrical waste. Mywaste.ie lists cables, cords and chargers as items for a WEEE drop-off point or civic amenity site, free of charge; do not bin them.
Sketch where the cable runs under floors and in the attic, and keep it with your house papers. The next person to lift a floorboard will thank you.
Running an Ethernet cable and fitting a data socket: questions people ask
Yes. Data cable carries no mains power. Plan the route, scan before you drill, pull it gently, terminate it carefully and test it. A new mains socket or anything at the board is for a Registered Electrical Contractor.
For a new run, Cat6. The Cat6 sheet we read rates it to 250 MHz, and it costs little more than Cat5e.
Not tighter than the maker allows. The sheet we read gives more than eight times the cable's outer diameter during installation.
Keep the data cable apart from mains cables where you can, and where it has to meet one, cross it squarely rather than running the two side by side.
Connect to your own router or a switch. Equipment your broadband operator installed belongs to the operator.
Locufy's Irish price guide puts data and network cabling at €150–€800 per job, typically €350. One run with a socket at each end is at the low end.
MORE GUIDES
More DIY guides
Sources — checked October 2026
- Dahua — 305 m U/UTP Cat6 LSZH cable specification: diameter, frequency, bending radius
- HSA — guide to Part 3 of the General Application Regulations 2007: electricity
- HSA — using ladders safely information sheet
- S.I. No. 264 of 2013 — Electricity Regulation Act 1999 (Restricted Electrical Works) Regulations
- CRU — RGI and Safe Electric schemes
- MyWaste.ie — cables, cords and chargers
- DIY.ie — Ethernet cables and connectors (price check)
- DIY.ie — Cat6 single outlet kit (price check)