Walls, microwaves, and weather: What really blocks your WiFi signal?

Walls, microwaves, and weather: What really blocks your WiFi signal?

Date: 19/09/23

Author: Anthony Harrison

If you find yourself constantly seeking a WiFi signal there might be something blocking it, like a certain material. But what are the true causes and reasons for WiFi signal blocks?

There are a lot of popular myths, but we can help unlock the mysteries with a list of materials and common objects that might interfere with your WiFi.

Let’s make sure it’s not something you’re doing wrong first. Take your router and:

  • Place it in a central spot so the signal can spread out evenly
  • Keep it away from other electronics, thick walls, or metal
  • Position the router antennas upright and pointed towards empty space

Let’s explore whether a material might be blocking your WiFi signal and lift the lid on what can interfere, and what cannot, with your internet.

Not sure if it’s the signal or something else? Learn how to check your WiFi signal strength.

Materials that block WiFi signal

Some sneaky materials are huge signal blockers you might not have thought about. Watch out for these everyday materials that might interfere with your WiFi:

  • Concrete: Thick concrete walls and ceilings can  reduce your WiFi signal.
  • Metal: Doors and panels can be signal-blocking, especially if they’re dense.
  • Brick: Even if they look great, brick walls and fireplaces might block your WiFi!
  • Water: Large aquariums, water tanks, and boilers can easily dampen your signal.
  • Mirrors: Even tiny mirrors can reflect WiFi waves away from where you want them.
  • Glass: Thick window glass or glazing with metallic coatings can block WiFi signal.
  • Plasterboard: Dense, insulated walls, like ones with metal inside, may block signal.
  • Furniture: Sofas, glass tables, and plush chairs can often become signal snuffers.
  • Insulation: Foam or fibreglass may help keep you warm–but can also block WiFi.

For some science on the matter, see this report from the U.S.-based National Institute of Standards and Technology, which covers many materials from concrete to plywood.

If these materials are around, Mesh WiFi systems can help by pushing signals seamlessly around obstacles. Discover how we use Mesh WiFi to guarantee WiFi in the rooms that matter most with our unbeatable Premium WiFi service – London’s fastest option to date. 

Want to make weak signal a thing of the past? Learn more about Mesh WiFi and how it works.

Objects and things that can block WiFi signal

There may be everyday objects in your midst that also block signal. Here are some WiFi signal blockers that could be ruining the speed and reliability of your internet:

  • Microwaves: These emit electromagnetic waves in a similar range as WiFi signals.
  • Cordless phones: Some models mess with the WiFi signals, giving you a blockage.
  • Baby monitors: They’re essential but may use frequencies that block your WiFi.
  • Bluetooth devices: Speakers, headphones, or keyboards, can interfere with WiFi.
  • LED bulbs: Low-quality bulbs might create electromagnetic interference.
  • TV antennas: Big antennas near your router can often play the role of WiFi barrier.
  • Metal appliances: Fridges or washing machines can reflect or absorb WiFi signals.
  • Bookshelves: Thick layers of paper, and the shelf itself, can easily block your WiFi.
  • Pet enclosures: Like dog crates, hamster cages, or anything using metal wires.

Keep an eye on these WiFi signal depleters and always try to find service providers who provide suitable routers that can handle the internet speeds you require.

Myth vs fact: What does and doesn’t block your WiFi

WiFi signals use a radio frequency range, so it’s things that also like to use this range that will interfere with your internet connection or cause blockages.

With that in mind, here are a few myth-busting tidbits about WiFi and signal blockers:

Yes (or maybe)


Microwaves: Possible, as they operate on a similar frequency–but modern WiFi uses other frequencies and shielding techniques.

Weather: Rain, snow, or fog do not directly block WiFi signals.

Plasterboard: Possible, but only if it is heavily insulated or has metal parts (and wires)–but not by itself.

Paper or cardboard: There is a very low chance of any interference for radio waves with such thin materials.

Fridges: If they are big and made of metal, a fridge can easily block WiFi signals.

Windows: Not a problem unless the glass is very thick, has a dense metal coating, or wires (like light switches) nearby.

Neighbour’s network: If a neighbour has a router very close to yours, like on the other side of a thin wall, it can easily interfere with WiFi signals.

Wood: WiFi signals pass through wood with minimal interference.


Still having issues? Learn more about how to boost your WiFi signal.

How to guarantee a better WiFi signal

Thick, dense materials like concrete can block WiFi signals, as well as certain objects that use the same frequencies. Router placement can help avoid interference and blockages.

WiFi extenders or Mesh WiFi systems can help expand your signal range and navigate obstacles. These high-tech routers help us deliver our Premium WiFi service guarantee. 

Your WiFi will be at your side wherever you roam throughout your home, which offers London’s highest speeds as part of our 1Gpbs and 3Gpbs service packages. 

We’ll shout you three months’ free broadband if it’s not possible. Sounds like a good plan? 

If you live in London, you can check your postcode for the availability of our broadband. See our blog for more news, tips, and updates on WiFi, signal, and other topics.

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