People usually blame slow office Wi-Fi on the broadband line, but the cause is often inside the building. Picture a router in a cupboard at one end of the office, pushing its signal through walls, filing cabinets and a kitchen full of appliances while half the team joins video calls at once. Paying for a faster package won’t help much there.

The fixes below start with finding where your coverage drops and moving the equipment you already have, both of which cost little or nothing. After that you’ll see how to deal with congestion from neighbouring networks, and how to choose between an extender, mesh and wired access points if you still need more hardware.

Finding the dead zones in your office

Plenty of offices buy an extender for the room everyone complains about, then discover the problem was somewhere else. It might be a stairwell cutting off the floor above, or an exterior wall blocking far more signal than anyone expected. Guessing quickly gets expensive.

A coverage survey tells you where the weak spots are. Walk the office with a laptop or Android phone running a Wi-Fi analyser app, plus a speed test, and note the signal strength and speed in each area. (iPhones restrict what third-party scanning apps can see, which makes them awkward for this job.) The app shows signal strength in dBm, as a negative number where closer to zero is better. As a rough guide, -67 dBm or stronger handles video calls well, and anything weaker than about -70 dBm needs checking. Watch for spots where the signal reads fine but the speed test still crawls, because those point to congestion rather than coverage.

Do the walk during your busiest hours. A quiet office at 7am will flatter your network, and you want to see how it copes when everyone’s on video calls. Spend extra time in meeting rooms, kitchens, lifts and stairwells, and anywhere near the exterior walls.

Check 2.4 GHz and 5 GHz separately

Most routers broadcast on two frequency bands, and newer Wi-Fi 6E or Wi-Fi 7 kit adds a third at 6 GHz. The 5 GHz band is generally faster but doesn’t reach as far. Signal on 2.4 GHz covers more ground but gets crowded more easily, which is how a desk ends up with a strong 2.4 GHz connection and a weak 5 GHz one. Record both, and most analysers will list them separately.

Where to put your router

The router ends up in the comms cupboard for one reason: that’s where the broadband line comes into the building. It’s a sensible home for the line and a poor one for Wi-Fi. Signal spreads outwards from its source, so a router at one end of the building spends a good chunk of its range on the car park.

You don’t need to move the line to fix this. Leave the router where it is and run an Ethernet cable to an access point (a separate unit that broadcasts Wi-Fi) in the middle of the floor, or move the router itself somewhere central and high. A high shelf in the middle of the open-plan area gives the signal a clear run in every direction. Thick walls, concrete, metal and glass all soak up signal, and so does a filing cabinet parked in front of the router.

While you’re in the cupboard, log in to the router and check for a firmware update. Firmware is the software built into the router, and updates often include performance and security fixes, and it’s far easier to install them before you move and mount everything.

Mounting height and antennas

Height and a clear line of sight help whatever you’re placing. For a router or wall-mounted access point, around 2 metres up works in most offices. Many business access points go on the ceiling, though, and send their signal downwards, so check the fitting instructions before you drill anything.

Keep everything well clear of microwaves, photocopiers, motors and thick bundles of cabling. And if your router has external antennas, point them straight up for coverage across one floor, or angle them diagonally if you need to reach the floor above or below.

Why does Wi-Fi slow down when the signal looks fine?

Ever had full bars on your laptop and a video call that still freezes? That’s congestion. In a shared building your network competes with the networks next door and with every device your own staff have connected, and all that traffic can drag speeds down even where the signal is strong.

Which Wi-Fi channel should you use?

Wi-Fi splits each band into channels, and your router picks one for you. Usually that’s fine. If your survey turned up slow speeds alongside a strong signal, though, it’s worth taking control. On 2.4 GHz only channels 1, 6 and 11 avoid overlapping each other, and the analyser will show which of them your neighbours are crowding. Manually switch the router to the quietest one and retest. People skip that last step more than any other, and the channel that’s quiet first thing can be packed by lunchtime.

Move video calls onto 5 GHz

Video calls and big file transfers belong on 5 GHz. Many routers have a band steering setting that automatically nudges devices onto 5 GHz when they support it. If yours doesn’t, give the 5 GHz band its own network name and connect work laptops to that one, which leaves 2.4 GHz for older devices that can’t use anything else.

Disconnect devices you don’t need

Look for devices doing heavy work in the background, like a laptop that’s spent a week syncing the same cloud folder or a PC downloading large updates during the working day. Your router’s admin page will usually list every connected device and, on many models, how much data each one uses. Disconnect anything that shouldn’t be there.

Extender, mesh or access points: which do you need?

Any dead zones left after you’ve moved equipment and cleared up congestion need more hardware. The right kind depends mostly on how easily you can run cables around the building.

An extender suits one weak corner or meeting room in a small office. It rebroadcasts the existing wireless signal, which can cut speeds sharply, so it’s fine for one room but no good for a whole floor. Place it about halfway between the router and the dead zone, where it can still pick up a decent signal to pass on.

Wired access points are the most reliable choice for a typical office. Each one connects back to the network by Ethernet and broadcasts a full-strength signal of its own. In a large or multi-floor office, the usual answer is several managed access points, which you set up and monitor from one dashboard. If nobody in-house has time to keep an eye on them, a managed IT support arrangement can cover that.

Mesh systems are quicker to install because the units link to each other wirelessly, but that wireless link slows things down the same way an extender does. They make most sense where cabling isn’t practical, such as a listed building or a leased space where you can’t drill through walls. Many mesh systems also let you cable the units together, which solves the speed problem wherever you can run a cable.

Plug in anything that doesn’t move

This gets overlooked far too often. A desktop PC that never moves has no reason to be on Wi-Fi if there’s a network port nearby, and the same goes for printers and projectors. Where there’s no port, a powerline adapter can carry the connection through the building’s electrical wiring. Every device you take off Wi-Fi leaves more room for the laptops and phones that need it.

Spacing out multiple access points

Aim for neighbouring access points to overlap their coverage by about 30%. That’s enough for people to stay connected as they walk between areas, and keeping it to around a third limits interference between the units. Once they’re up, walk the office with your analyser again and adjust their positions and channels.

Quick checks, in order

One rule applies all the way through: change one thing at a time, then retest from the same spots with the same analyser. If you move the router, switch channels and add an extender on the same afternoon, you won’t know which one fixed the problem (or which one made something else worse).

Map weak spots and slow spots with a Wi-Fi analyser and speed test during busy hours.
Update the router’s firmware before you start moving anything.
Move the router, or add a cabled access point, so the signal starts somewhere central and high.
Switch 2.4 GHz to the quietest of channels 1, 6 and 11 if the automatic choice is struggling.
Turn on band steering, or set up a separate 5 GHz network, for laptops and video calls.
Plug desktops, printers and other fixed devices in with Ethernet wherever there’s a port.
Cover any remaining dead zones with wired access points, or with mesh where cabling isn’t practical.

What to expect, and when to call in help

In many offices, moving the router and sorting out channels clears most of the complaints on its own. The difference often shows first in meeting rooms, where video calls stop dropping, and at desks that used to sit on the edge of the signal.

If dead zones remain, go back to your survey notes. They show roughly where an access point or mesh unit needs to go and what reading it has to improve on, so you’re buying hardware for a specific gap instead of hoping. If you’re still stuck after that, it’s time for a professional site survey.

Rechecking coverage as the office changes

Wi-Fi coverage doesn’t stay fixed. A new partition goes up, a team moves to the other end of the floor, or someone parks a fridge right next to the access point, and a spot that was fine last year starts dropping calls. Whenever the layout shifts or the grumbling starts creeping back, grab the laptop and walk the same route again. It doesn’t take long, and it’ll usually show you what’s changed.

If you’d rather someone else did the walking round with a laptop, that’s the sort of day-to-day IT work Absolute Consultancy Services handles for SMEs across Ashton-under-Lyne and the wider Northwest. You can reach the team on 0161 850 0682 or at info@absolutecs.co.uk.