The complaint that brings me to TVs is always the same. "It buffers in the middle of films." "The picture goes blocky for a few seconds and then comes back." "It says 'Wi-Fi signal weak' even though the router is in the next room." All the same problem: the TV is on the wrong side of a WiFi signal that can't sustain 4K reliably.
Why WiFi struggles with 4K
4K streaming from Netflix or Disney+ needs a sustained 25Mbps. That's not a peak — it's the average over each second of playback. Drop below that for more than a few seconds and the stream either buffers (cheap players) or downshifts to lower resolution (smart players, which is why the picture suddenly looks blocky).
WiFi delivers 25Mbps comfortably when the signal is strong. The problem is most TVs aren't where the signal is strong. They're against a wall, often behind metal stands or in front of a fireplace, sometimes with the back of the TV (where the WiFi antenna lives) facing into the wall instead of into the room. Signal strength at the TV's antenna position is usually 20-40% lower than at head height in the same room.
Add the typical Victorian-house penalty (signal travelling through one or two brick walls from the router), and your TV is trying to sustain 25Mbps on a connection that's getting maybe 18 with occasional drops. Result: buffering.
What a wired install actually is
One Cat6 cable, run from a port on your router (or a small switch near the router) to a wall plate behind your TV. The TV plugs into the wall plate with a short ethernet patch lead. Done.
Performance is gigabit (1000Mbps) end-to-end if your TV supports it, or 100Mbps on older sets — either way, dramatically more than the 25Mbps you actually need. The cable doesn't care about brick walls, foil-backed insulation or where the router is. It carries the full data, every time, no exceptions.
From the customer's side, the TV menu suddenly shows "Connected — Wired" instead of "Connected — Wi-Fi", and the buffering stops.
James in Hackney runs his home as a working setup — video editor, big NAS in the cupboard, 4K reference monitor in the living room. Before I installed the proper structured cabling for him, his TV was the worst-affected device in the flat. Dropbox syncs were failing on his desktop, but the visible problem was that his 4K reference monitor (which doubles as the living room TV) was downsampling Netflix to HD every other evening.
His warehouse-conversion flat had a single Cat5e cable run by the developer behind the TV. That sounds like it should have been the fix already — but on inspection it was a daisy-chain of Cat5e patch leads (not solid-core install cable), badly crimped at both ends, running 12 metres through the cable tray with no consideration of separation from the mains. Speed-tested at 60Mbps where it should have been 940.
I pulled it out, replaced it with proper solid-core Cat6 terminated to a keystone jack at the wall plate, a Cat6 patch lead from there to the TV. Speed: 940Mbps sustained. Streaming issues gone. That was alongside the rest of his Cat6 work (desk, NAS, spare), but the TV connection was the single biggest user-visible improvement.
The route
Where the cable runs depends on your specific property. The common routes I use:
- Down through the floor (if the router is upstairs and the TV is downstairs): drill through the floor near the router, drop the cable into the floor void, run across the joists, drill up through the ceiling near the TV. Often invisible.
- Up through the floor (router downstairs, TV upstairs): reverse of the above.
- Around the perimeter via skirting voids (same-floor): lift skirting boards along the route, lay cable in the gap behind, refit. Works in most pre-1980s houses where the skirting isn't a single fitted unit.
- Through stud walls (same-floor, modern flats): drill at top and bottom, fish the cable down the wall cavity, terminate at a wall plate.
- Behind a TV bracket recess (if the TV is wall-mounted): with a recessed wall plate behind the TV, the cable disappears completely. Brilliant if the TV is going up anyway.
What's at each end
At the router end: either a direct connection from one of the router's LAN ports (if there's a spare), or a small unmanaged switch if you've used up the router's ports. Either way, the cable terminates to a wall plate on the wall behind the router, with a short patch lead from the wall plate to the router.
At the TV end: a single wall plate with one ethernet port, mounted behind the TV at a height where it won't be visible. A short patch lead from the wall plate to the TV's ethernet port. If the wall plate is well-positioned, the lead is hidden by the TV itself.
What we test
Every Cat6 install I do gets tested with a Fluke MicroScanner before I leave:
- Wiremap: proves all 8 wires in the cable are correctly connected at both ends. Catches the most common termination mistakes (swapped pairs, missed wires).
- Length: confirms the cable is within spec (under 100m for gigabit performance — almost always under 30m for a single TV run).
- Signal-to-noise / NEXT (Near-End Crosstalk): proves the terminations are correctly twisted and the cable is delivering its rated performance.
If anything fails, we retest the terminations until it passes. Customer gets a printout of the test certificate. The whole thing takes about 3 minutes.
Can you DIY this?
For a simple route with good access — yes. You need:
- Cat6 cable (solid-core, not stranded patch cable). Cheap Cat6 from generic online sellers often turns out to be copper-clad aluminium — fine for short runs but fails on longer ones. Stick to known brands.
- One single-gang back box + wall plate with a Cat6 keystone module.
- A Cat6 keystone jack at the router end (or a small unmanaged switch).
- An IDC punchdown tool.
- A short ethernet patch lead at each end.
The cable termination takes practice — most first-time DIYers get the pinout wrong (T568A vs T568B — use B unless you have a specific reason) or untwist the pairs too far at termination (leave no more than 13mm of untwisted wire).
Where DIY usually goes wrong: the route. Fishing cable through stud walls takes a fishing tool (a fibreglass rod or a roll of cable mouse), and access points usually need cutting in places you'd rather not cut. Most amateur installs end up with the cable visible somewhere it doesn't need to be, because the chosen route turned out to be harder than expected.
If you're confident and the route is straightforward (e.g. same floor, lifting skirting on a carpeted floor), a Saturday morning gets it done. If the route involves drilling through joists or fishing through stud walls — getting an engineer in is usually the right call.
Common questions
Why is WiFi not good enough for 4K?
4K needs about 25Mbps sustained — WiFi delivers that easily when signal is strong. But TVs are usually in positions where signal is weakest (against walls, behind cabinets, in front of fireplaces). Wired is consistent; WiFi is a coin flip.
How long does the install take?
1–3 hours depending on the route. Same-floor with good access — about 90 minutes. Through-floor or through-wall — about 3 hours.
Can I do it myself?
Yes, if you're handy and the route is straightforward. Cat6 cable, a keystone jack, a wall plate, and a punchdown tool will get the parts on the bench. Where DIY fails is fishing the cable through unexpected obstacles in the chosen route, and proper termination technique (don't untwist the pairs more than 13mm).
Want a wired TV that doesn't buffer?
Tell me where the router is, where the TV is, and what's between them. Ring me and we'll talk it through — usually 90 seconds — and book it in for the same week.