Full bars in the reception, nothing in room 12. Video calls that freeze when you walk to the kitchen. Guests complaining in reviews. Wi-Fi dead zones are one of the most common building complaints, and one of the most often "fixed" the wrong way, with another cheap extender plugged into a socket.
Full bars in the reception, nothing in room 12. Video calls that freeze when you walk to the kitchen. Guests complaining in reviews. Wi-Fi dead zones are one of the most common building complaints, and one of the most often "fixed" the wrong way, with another cheap extender plugged into a socket.
This guide explains why dead zones happen, how to map them with just a phone, and which fix actually works for your building.
You need only a phone and a floor plan (a hand-drawn sketch is fine).
| Signal (dBm) | What it means |
|---|---|
| −30 to −60 | Excellent to very good |
| −60 to −67 | Good: fine for video calls and streaming |
| −67 to −75 | Usable for browsing; calls may struggle |
| Weaker than −75 | Poor: expect drop-outs |
When you finish, you will have a simple map that shows where the problem is and which walls cause it. This is a basic survey, not a professional one, but it is often enough to plan a fix.
Before buying anything, put the router or access point high, central and in the open: on a wall or shelf, not on the floor, not inside a cabinet, and away from metal and large mirrors. Point external antennas vertically. This is free and sometimes enough for a small house or office.
On 2.4 GHz, only channels 1, 6 and 11 do not overlap with each other. Use one of them, and choose the least crowded according to your analyser. Keep 2.4 GHz at 20 MHz channel width. Wider channels on 2.4 GHz cause more interference than they are worth.
Use 5 GHz for most devices where signal allows. It has many more channels and less interference, but it does not travel through walls as well, so it needs access points closer to users. Newer equipment also supports 6 GHz, which has even shorter range through walls.
Combine your guest and staff networks where you can, or keep the number of network names to two or three.
A typical plug-in extender has to receive data from the router and retransmit it to your device, often on the same radio and channel. It cannot do both at once, so the airtime is shared, and throughput through an extender is roughly half of what it receives, at best. Chain two extenders and it drops further. The extender also needs good signal itself, so it must sit where the router signal is still strong. Behind a thick wall, it simply repeats a weak signal.
Extenders can be a quick fix for one small room. They are not a solution for a building.
A mesh system uses several units that work together as one network, with the same name, and helps devices move between them. Better mesh systems have a dedicated radio for backhaul (the link between units), which avoids most of the extender speed loss.
Mesh suits homes, villas and small offices where running cables is difficult. Its limits are the same walls: if the units cannot hear each other well through coral stone, the backhaul is weak and so is everything after it. Many mesh systems can use an Ethernet cable as backhaul, which is far better.
For hotels, guesthouses, schools, hospitals and offices, the reliable answer is ceiling- or wall-mounted access points connected by Ethernet cable, powered by PoE and managed from one controller. Each access point serves a small area at moderate power. Devices roam between them. Speed does not halve because each one has its own wired connection back to the network.
Typical good practice:
Our comparison of mesh Wi-Fi versus managed access points goes into more detail.
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In Stone Town, a UNESCO World Heritage Site, visible changes to building exteriors need approval from the conservation authority. Plan cable routes and outdoor equipment discreetly, inside the building where possible, and check with the authority before fixing anything to a façade. Inside, existing ducts, ceiling voids and skirting runs can often hide new cabling.
Warning Installing ceiling access points and running cables means working at height on ladders and, often, near electrical wiring in ceiling voids. Use a stable ladder with someone holding it, and turn off nearby circuits or leave the work to qualified installers. Never drill into walls without checking for hidden pipes and cables.
Pool decks, gardens and car parks need outdoor-rated access points (look for an IP66 or IP67 rating) with sealed connectors and stainless fixings, especially near the sea. Outdoor cable runs should have surge protection and proper earthing because of lightning.
Call a professional if your building has several floors, more than a handful of rooms, outdoor areas, or users who depend on the Wi-Fi for business. Also call one if you have already added extenders or mesh units and the problem is no better. Before calling, collect:
Rarely. Even if the router shouts louder, phones and laptops transmit at low power and cannot shout back through thick walls. More access points closer to users work better than one powerful router.
Mesh with wired backhaul is close. Wireless mesh is good for homes and small offices, but in large buildings with thick walls, wired access points are more reliable and faster.
Use both. 2.4 GHz travels further through walls but is crowded and slower. 5 GHz is faster and less congested but has shorter range. Good access point placement makes 5 GHz usable throughout.
It depends on wall materials, layout and the number of users. In coral-stone or concrete buildings, plan on more than you would expect. A survey is the only reliable way to tell.
You can do a basic one with a phone app, as described above, and it is useful. A professional survey uses calibrated tools and predictive planning and is worth it for hotels, hospitals and large offices.
Extrion Tech surveys buildings, designs Wi-Fi coverage and installs wired access point networks with PoE, UPS backup and central management. See our network architecture and infrastructure service or contact us with your floor plan and readings.
This guide is general information to help you plan. Prices, product features and regulations change, so confirm the details for your own site before you buy.
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