Fit-out cabling
Counting drops for a floor and planning the pathways they run in. Covers what actually needs a cable now that most devices are wireless, why the answer is still more than people expect, how to size containment so the next change is a pull rather than a rebuild, and where the telecom room has to be for the whole thing to certify.
Doing it
Planning the floor before anything is pulled, starting with the decisions that are expensive to reverse.
- Floor plan at a known scale
- Measuring wheel or laser distance meter
- 01
Start from the ceiling and the walls, not the desks
Access points, cameras, door controllers, displays, and clocks are all cabled, and on a modern floor they frequently outnumber the desk drops. Count them first, because they set where containment has to go and they are the ones forgotten in a desk-based count.
- 02
Count desk drops against how the floor is actually used
A hot-desked floor with laptops and docks needs fewer than a fixed-seat floor with desk phones and desktops, and a trading or dealing position needs several. Ask what sits on the desk today and what the client thinks sits there in three years, then specify for the larger of the two.
- 03
Place the telecom room before you count metres
Every horizontal run has to reach it within 90 metres of cable — not 90 metres as the crow flies, but the real path up into containment, along it, and back down. A room in a convenient corner rather than near the centre is the usual reason a floor needs a second one nobody budgeted for.
CautionMeasure the route, not the straight line. Vertical rises and detours around structure regularly add a third to the length.
- 04
Size the pathway for the second install, not the first
Containment filled to capacity on day one means the next change is a new pathway rather than a pull. Fill to roughly half, plan where a future bundle would enter and leave, and put draw strings in anything enclosed. This is the cheapest decision on the job and the one most often skipped.
- 05
Keep the route legal and serviceable
Cable in a return-air ceiling has to be rated for it. Anything crossing a fire compartment needs the penetration made good. J-hooks belong on structure, not on ceiling grid wire, sprinkler pipe, or someone else's conduit — and a run laid on top of a ceiling tile is not a pathway, it is a future fault.
CautionPlenum rating and firestopping are inspection items. Getting them wrong means opening the ceiling again with somebody watching.
- 06
Specify the category against the life of the fit-out
A five-year fit-out and a fifteen-year one are different answers. The cable is a small fraction of the installed cost and the labour to replace it is most of it, which is the whole argument for putting in more capability than today's switches can use.
- 07
Number the floor before anything is pulled
Agree the labelling scheme and put the numbers on the drawing first. Runs pulled before the scheme exists get labelled from memory afterwards, which is how a panel ends up with two ports called the same thing.
- How many network drops does a desk need?
- Two per seat is the common baseline — one for the machine or dock and one spare — with a third where a desk phone or a second device is fixed. A hot-desked laptop floor can work on fewer; a fixed-seat, multi-screen or dealing position needs more. The spare is not padding: it is what turns the next change into a patch rather than a pull.
- Do we still need cabling if everything is wireless?
- Yes, and often more of it than a cabled floor needed. Every access point is a cabled drop, usually two, and good coverage means many of them. Cameras, door controllers, displays and sensors are all cabled too. Going wireless moves the cable from the desk to the ceiling; it does not remove it.
- How far can a run be?
- Ninety metres of horizontal cable, plus up to ten metres of patch cords, for a hundred-metre channel. What catches people out is that the ninety metres is the real route — up, along, around structure, and back down — not the distance across the floor plan. Measure the path.
- Cat6 or Cat6a?
- Decide it on the life of the fit-out and on whether the run will carry high-wattage PoE, not on today's switch. Cat6a is specified for 10GBASE-T across a full channel and handles the heat of 802.3bt in a bundle better. The cable is a minor part of the installed cost; the labour to replace it later is most of it.
- Where should the telecom room go?
- As close to the centre of the area it serves as the building allows, so the furthest drop still comes in under length with the real route measured. A room pushed to a corner for convenience is the usual reason a floor needs a second one, which costs far more than the space it was meant to save.
The rest of the section
- 01RJ45 Wiring: T568A and T568BBoth colour codes, pin by pin, side by side.
- 02RJ11 Wiring and Phone PinoutsSix positions, three lines, two colour systems.
- 03Keystone Jack TerminationStrip, seat, punch, snap — without failing the certification.
- 0466 Block WiringFifty rows, four columns, and where the bridging clips go.
- 05110 Block WiringLay the pairs in, press the connecting block on.
- 06Cat5e vs Cat6 vs Cat6a vs Cat8Speed, distance, and power decide it — not the bigger number.
- 07Fibre Types, Connectors and PolishRead the jacket, read the connector, don't mate blue to green.
- 08Subnetting, ExplainedWhere the numbers come from, and the meaning behind them.
- 09PoE Standards and Why It Won't PowerThe switch reserves the class, not the draw.
- 10Camera Lens, Field of View and Pixel DensityCovering the room is not the same as identifying a face in it.
- 11Patch Panels and Labelling to TIA-606A label that survives is worth more than a tidy rack.
- 12Rack Planning: Units, Depth, Weight and HeatIt fits vertically. That was never the hard part.
- 13Writing a Switch ConfigurationFrom factory default to a switch you would hand over.
- 14Networking and Cabling GlossaryThe terms, and what they mean on a job.
- 15POTS to VoIP: What BreaksThe lines nobody remembers until they stop working.
- 16Testing an Analogue Phone LineTip, ring, and the four numbers that tell you whose fault it is.
- 17Toning and Tracing a CableFinding one pair in a bundle of two hundred.
- 18Reading a Cable Certifier ReportWhat PASS* actually means, and which number to look at first.
- 19Which Cable Tester Do You Need?Three tiers, and the one most people actually need.
- 20Running an Office Floor RestackEveryone sits down Monday and their machine works.
- 21Cable Management for Desks and RacksTidy is a by-product. Serviceable is the point.
- 22Asset Tagging and CMDB AuditsThe scan is easy. Scanning it into the right record is the job.
- 23Parcel Locker Site SurveysWhether the unit fits, powers, connects — and gets in the door.
- 24VLANs and TrunkingAccess, trunk, tagged, native — and which one is the security hole.
- 25Spanning Tree and Switching LoopsWhy one patch cord can take a whole floor down in seconds.
- 26Reading a TracerouteWhich loss is real, and whose network it is in.
- 27DHCP, DNS and Helper AddressesWhy the new VLAN gets no addresses, and why it is always DNS.
- 28Wi-Fi Channel Planning and AP PlacementMore access points at lower power, not fewer at maximum.
- 29SMART Attributes That Predict FailureA drive can report PASSED while it is visibly dying.
- 30BitLocker: Keys, Recovery and EscrowThe key exists somewhere, or the data does not.
- 31Grounding and Bonding a Telecom RoomOne ground, one path, and no loops between rooms.
- 32UPS Sizing: VA, Watts and RuntimeThe number on the box is not the number you need.
- 33Mounting Displays on Any WallFind the structure. Everything else is a repair bill.
- 34Mounting IP CamerasHeight, angle, and the surfaces that ruin the picture at night.
We do this work
as well as document it
Anyone pricing or specifying cabling for a floor, and anyone being asked how many drops a new office needs.