Networking and Wi-Fi
Wi-Fi dead zones and coverage fixes (NZ)
This guide is about coverage: rooms where Wi-Fi is weak or unreliable, devices that cling to the wrong access point, and "it works next to the router but not in the bedroom/office" problems. It is different from slow internet troubleshooting.
Dead zone or slow internet? Decide the problem first
Before you buy new gear, decide which category you are in:
- Coverage problem: Wi-Fi signal drops off in specific rooms, behind walls, or at the far end of a building.
- Stability problem: Wi-Fi disconnects or freezes even near the router, or devices randomly "lose internet".
- Upstream problem: the fibre connection itself drops out, or speeds are poor even on a wired connection.
If you suspect upstream issues, start with the Wi-Fi and slow internet troubleshooting checklist (it focuses on fault isolation and ISP escalation evidence). This page focuses on coverage and layout.
1) Map the coverage with two simple measurements
You do not need fancy tools to get a useful map. Two measurements are enough:
- Signal strength (RSSI): most Wi-Fi apps show this as dBm. Lower (more negative) is weaker.
- Consistency: does the signal stay stable, or does it bounce around when you stand still?
For SMEs, write down: which device you tested on, where you stood, and roughly what time. This kind of simple evidence is what makes follow-up work faster and reduces guesswork.
Coverage evidence that makes upgrades safer
A coverage map is more useful when it separates signal strength from actual user experience. A room might show a weak signal but still work for email, while another room may show acceptable signal but fail video calls because of roaming, interference, or access-point load.
Room-by-room notes
Record each work area, the test device, signal strength, whether video calls work, and whether performance changes when doors are closed.
Device class
Test at least one phone, one laptop, and any business-critical device. Different Wi-Fi chipsets can behave differently in the same room.
Wired comparison
Compare Wi-Fi against a wired test near the router. If wired performance is poor too, this is not only a coverage project.
Before-and-after baseline
Keep the old map. After moving a router or adding an access point, retest the same rooms so improvement is measurable.
2) Router placement fixes more than people expect
In NZ, the fibre ONT and router often end up in a garage or corner because that is where the install happened. Coverage will be worse if the router is:
- inside a metal cabinet or behind a TV/AV rack,
- on the floor, behind furniture, or inside a cupboard,
- next to big sources of interference (some appliances, thick masonry walls, foil insulation),
- in a far corner of the building.
A simple improvement is moving the router higher and more central. If the ONT cannot move, consider a single wired access point in a better location.
3) Mesh vs access points (and why wired backhaul matters)
The two common upgrade patterns are:
- Mesh system: multiple nodes that try to extend coverage automatically.
- Wired access points: one or more access points connected by Ethernet to the router or a switch.
If you can run Ethernet to an access point, wired access points usually produce the most predictable results. Mesh can work well, but mesh nodes that talk to each other wirelessly can lose performance as you add hops. In plain terms: the "backhaul" link matters.
For small offices, a good compromise is: keep the ISP router (for fibre/voice), disable its Wi-Fi if necessary, then run one or two wired access points for consistent coverage.
A simple decision rule: mesh, wired access point, or router move?
Buying more Wi-Fi hardware is easy. Choosing the right kind is harder. Start with the cheapest reversible option, then move toward cabling or extra access points only when the evidence supports it.
Router move
Best when the router is in a cupboard, garage, floor corner, TV cabinet, or far from the rooms where people work.
Mesh system
Best when cabling is impractical and the nodes can still see each other clearly. Bad node placement creates attractive but slow Wi-Fi.
Wired access point
Best when you can run Ethernet to the area that needs coverage. It usually gives more predictable performance than wireless backhaul.
Router replacement
Best when the existing router is old, overloaded, unreliable, unsupported, or cannot handle the number of devices and current security expectations.
4) 2.4 GHz vs 5 GHz and channel planning
Quick rules of thumb:
- 2.4 GHz travels further and penetrates walls better, but it is crowded and often slower.
- 5 GHz is usually faster and cleaner, but range is shorter.
If a device is far from the router, 2.4 GHz can be more stable. If you are close, 5 GHz is often better. If you have multiple access points, channel planning matters because "auto" can pick overlapping channels that fight each other.
5) Roaming problems: devices clinging to the wrong node
A common complaint is: "Wi-Fi is fine upstairs, but my phone won't switch when I walk downstairs." That is a roaming behavior issue: some clients hold onto a weak connection longer than you would expect.
- If you have a mesh system, check if it supports "client steering" or roaming assistance.
- If you have multiple SSIDs, simplify (one SSID per band is sometimes helpful during diagnosis).
- When in doubt, test by toggling Wi-Fi off/on on the device after moving rooms.
Official NZ context for performance and router hygiene
Coverage work still needs current, practical reference points. These sources help separate in-home Wi-Fi performance from broadband performance, and remind SMEs that routers and access points are also security-sensitive devices.
In-home performance
The Commerce Commission's RealSpeed work separates performance to the router from performance experienced on devices in the home.
Broadband monitoring
Measuring Broadband New Zealand provides independent broadband performance information across providers, plans, and technologies.
Router hygiene
NCSC's router security guidance highlights firmware updates and the risk of compromised small-office/home-office routers.
Provider escalation
If coverage work shows the problem is upstream, move back to timestamps, wired tests, ONT/router state, and provider evidence.
6) When upgrading hardware is actually the right move
After placement and a basic coverage map, an upgrade makes sense when:
- you have clear dead zones that are predictable,
- the building layout is Wi-Fi-hostile (thick walls, long corridors, multiple levels),
- you have more devices than the router handles reliably,
- you need stable video calls or VoIP on Wi-Fi across the building.
If the issue is stability even near the router, treat it as a troubleshooting job first. Hardware might help, but it is not always the root cause.
7) Write handover notes so the next change is safe
If you change Wi-Fi configuration without notes, the next issue becomes harder. A simple handover note includes:
- router model, firmware version, and ISP,
- SSID names and which devices use them,
- where access points/nodes are physically placed,
- what changed and when,
- how to roll back if the change makes something worse.
This is the same mindset used across the rest of the site: practical documentation you can maintain. For more context, see About John Finnerty and the Projects hub.
Related services
Wi-Fi support and fault isolation
If you are in Christchurch and want hands-on follow-up, the Wi-Fi service page describes the workflow and the kind of evidence that helps. If you are troubleshooting speed and dropouts (not just coverage), use the slow-internet checklist first.