10 Most Common Materials that Block WiFi Signals

graphic of common materials that block wifi

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While WiFi is undoubtedly fantastic, it’s nowhere near perfect in practice. Many people regularly deal with slow internet, sudden connection drops, and more. People also struggle against various privacy and security risks due to hackers using wireless networks to steal data and plant nefarious malware. 

In this guide, we focus on the main cause of WiFi issues. A poor connection can be caused by fundamental tech or hardware issues, but more times than not it’s the result of various materials near your WiFi router that actively block your internet signal. 

10 Materials That Block WiFi Signals

All devices with wireless connectivity are susceptible to signal interference, and WiFi is no exception. Countless obstacles can interfere with your signal, but the primary culprit tends to be a range of different building materials.

The following is a selection of some of the most common types of building materials that block your WiFi signal. If your router is placed near any of the following materials, you should consider moving it to a different location to boost the power and efficiency of your wireless internet connection.


Metal is the most challenging material to penetrate because it’s a great conductor of electricity. Because WiFi is electromagnetic, metal has the unique ability to absorb it and cancel out the signal. Anything made of metal, from doors, walls, and building infrastructure, can significantly reduce or even terminate your WiFi signal. The more metal that stands between your router and the device you’re trying to connect, the worse the WiFi signal is likely to be. 

Concrete Walls

Concrete is a very thick material, so there’s little wonder as to why it would be difficult for WiFi signals to penetrate it. The thicker the concrete involved, the harder the WiFi signal has to work to make it through the obstacle, even with the added assistance of a WiFi booster. It becomes even more complicated if the concrete is coupled with metal laths.

Plaster & Drywall

Plaster and drywall are prevalent building materials in most homes and businesses. Thankfully, because they tend to be relatively weak and thin, they have the smallest amount of impact on your WiFi signal. That said, they can still weaken it, especially if there’s a wall between your router and the device you’re trying to connect.

Ceramic Tile

Ceramic tile is another commonly used material for floors and walls, and like with drywall and plaster, WiFi signals are generally weakened as they pass through it. However, because tiles are often combined with plaster or drywall, the materials are likely to increase WiFi interference. This is also why placing your router in a high, central location within your home is considered best practice. The further away it is from floors and walls, the better.


You wouldn’t think windows would interfere with your WiFi since they’re clear and great at letting light in, but the truth is that they can reflect your signal. This is especially the case for Low-E (low-emissivity) windows, which contain a type of metallic film to help reduce energy consumption. The addition of the metallic film makes it even easier to absorb or interfere with WiFi signals.


Like windows, mirrors are reflective and contain a thin coating of metal behind their glass. Combining these two elements allows them to cause a decent amount of electromagnetic interference. However, the extent that the mirror will interfere with your WiFi signal depends on its size. So an entire wall of mirrors will be much more harmful than a smaller one. 


Anything containing a considerable amount of water can reduce the strength of your WiFi signals, such as a fish tank and even you as a human. WiFi signals struggle to pass through water, which can significantly reduce its speed and the ability of your devices to connect to it effectively.


Furniture creates several obstacles for your WiFi signal to contend with. The more furniture you have, and the bigger and thicker it is, the more your signal will experience disruption. If your router is currently hiding behind any furniture or is too close to any, move it to a more open, less obstructed area. Or, consider rearranging your furniture against the walls or eliminating unnecessary items altogether to help improve your WiFi coverage.

Home Appliances

Large household appliances like washing machines, microwaves, dishwashers, ovens, refrigerators, and even air conditioners can disrupt and weaken the strength of your WiFi signal because they contain metal and electrical components. You’ll want to make sure your router is far away from any of these appliances to avoid interference. 

Metallic Blinds

We’ve already talked a lot about how any metal can cause issues with your WiFi signal, so it shouldn’t be surprising that metallic blinds can also be an issue. While not completely necessary, it may be helpful to invest in fabric or paper blinds if you need more ways to strengthen your WiFi signal and have already tried everything else.

Other Things That Interfere With WiFi

While the building materials above are the most common cause of signal interference and outright blockage, several other factors can also impede your signal and make it difficult to connect to the internet. Some of these factors include:


Any wireless Bluetooth device – from keyboards and headsets to mice and microphones – can interfere with your WiFi signal. This interference occurs because Bluetooth uses specialized technology to promote frequency hopping, which can clog up signal traffic and create delays in your connection.

Your Neighbor’s WiFi Network

Have you ever noticed that options to connect to nearby networks will typically appear on your device? Well, the truth is that those nearby signals may be hindering your broadband connection, especially if your neighbors use the same wireless channel as you or an overlapping channel. While this shouldn’t be enough to block or erase your signal, it’s likely to weaken and slow it down.

Nanny Cams & Wireless Security Cameras

Any analog video sender – from wireless security cameras to nanny cams – can be a source of WiFi disruption in your home. Actually, anything that can transmit pictures via satellite or cable to a computer monitor or TV can strongly impact the strength of your WiFi signal. And because these devices typically have such a broad reach, they can also negatively impact the WiFi signal of your neighbors. 

Final Thoughts

If you frequently struggle with weak or dropped signals, applying the above information will likely help you find a solution to the issue. If you want to improve your wireless internet, ensure your WiFi router is not located near any problematic materials or devices that can actively hinder its performance.

Granted, if that doesn’t work, it may be a sign that you need to upgrade your current internet plan or switch over to a different internet service provider altogether. Our experts can help you compare the best internet, tv, and bundle deals currently available in your area. 

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Marla Milano
Marla is a Contributing Writer for HighSpeedOptions, assisting in HighSpeedOptions’ coverage of satellite internet, streaming, and TV content. She comes with five years of experience writing for lifestyle and tech brands across multiple industries and has a BA in Marketing and MA in Digital Communication and Media Arts from DePaul University. Marla is passionate about not only integrating a creative edge into her work but also pulling data-driven insights to enhance her thought process.