Get Started
green building materials

What Materials Can Block Mobile Phone & Wi-Fi Signals

Table of contents

Some building materials reduce a mobile signal and negatively impact the quality of calls. This is why you cannot make a call or send a text when you are in an underground car park or in some commercial buildings. As the mobile signal is transmitted from mobile towers to your devices, an unfortunate choice for building material can jeopardise your communication and disrupt your calls with colleagues, clients, and even family and friends. But what materials can block or worsen mobile reception? In this article, we will go over the seven most popular building materials used worldwide that can cause connection issues as well as take a look at the solution from UCtel.

7 Building Materials that Block Mobile Phone and Wi-Fi Signals

We have selected the most common materials that are used in residential and commercial construction and block your phone or wireless signal. 

Low-E glass

Low-E glass, or low-emissivity glass, is a type of green building material that is commonly used in office and residential buildings. The purpose of Low-E glass is to reduce the amount of heat that makes its way into a building through glass windows or doors without minimising the amount of light. As a result, people inside the building can enjoy the coolness and save on energy bills. 

Although Low-E glass has become quite popular because of its eco-friendliness, it is one of the materials that block a mobile phone signal. Low-E glass subtracts 40dB from your mobile phone signal, which can be quite damaging to the quality of the calls. 

Fibreglass insulation 

Fibreglass insulation is a go-to choice for many homeowners as it is cheap, effective, and easy to install. Not only does it protect you from the heat in the summer and cold in the winter, but fibreglass is also known to be moisture and fire-resistant, keeping your belongings safe even in case of a flood or fire. Additionally, fibreglass is extremely durable, eco-friendly, and will even soundproof the premises. 

No wonder fibreglass insulation is a popular choice to insulate and soundproof a house. Unfortunately, it comes at a price: it can block mobile signals. Even though fibreglass is a lightweight building material, it is often applied in thick layers to ensure efficiency. Moreover, foil is often applied to insulation material to enhance the effect even further. As a result, this mobile phone signal blocking material can deteriorate your phone reception by 2dB. 


When it comes to wood, it is important to note what material blocks mobile phone signals the most. For example, wood materials like beech, ash, maple, oak, or mahogany can substantially affect the quality of the signal, up to -12dB. On the other hand, Plywood reduces the reception by 6 to 9dB, which is also quite damaging but to a lesser degree. 

Additionally, natural woods near your house can be accountable for your poor mobile signal. Depending on the forest type and density, your signal might experience a loss range from 5 to 12dB. 


If you are experiencing poor connection at home and can’t figure out which material disrupts your signal, there is a huge possibility that you have brick walls. As a tenant, you might not even know what is behind the layer of paint or paper wall. Brick walls are quite popular in residential construction as they keep you warm in the winter and warm in the summer. It is also an affordable building material, but it can block your mobile and WiFi signal. 

Besides brick, we can also mention kitchen or bathroom tiles as well as stone. Depending on the thickness and the density of the brick construction, you may be losing somewhere from 8 to 28dB. 


Concrete is not one of the materials that block WiFi and mobile signals inside your office or kitchen as it is commonly used as a building foundation, material for the roads and bridges. Due to its thickness and density, the reason for using concrete is its ability to withstand enormous weights. 

You have certainly faced a reception issue or mobile signal blocking with concrete in a car park or basement. Although it realises its purpose and prevents buildings from falling down, it is one of the most significant mobile signal blockers out there. You will experience a 10 to 20dB deficit in the mobile signal quality. 


Although concrete and Low-E glass look like the answer to the question “What materials can block mobile phone signals the most?”, wait until you find out the number for metal. Metal, being a building material that is used everywhere, in commercial buildings, offices, hospitals, shopping centres, residential homes, etc., is the most disruptive element. 

Whether it is aluminium, brass, copper, iron, or any other type of metal, it will cause the most damage to the call reception. When getting through a metal barrier, the mobile signal loses up to 50dB. 


Plasterboard is used in schools, hospitals, shopping malls, and residential homes to build partitions, wall linings, or ceilings. Plasterboard is at the bottom of our list as it is the least harmful on our list of construction materials that disrupt a mobile signal. Although, if your signal is already weak to begin with, even a small interference can cause issues to your calls. You can lose up to 2dB if you are surrounded by plasterboard material. 

How Can We Help Improve the Signal in the Building?

With a mobile phone signal booster solution from Cel-Fi, you can allow your mobile phone signal to bypass even hard-to-penetrate construction materials entirely using a network of indoor antenna systems. 

An external antenna can be set up wherever the mobile phone signal is strongest. Mobile phone signal is boosted using an internal amplifier and fed indoors via a cable to an indoor antenna. This can be stretched out across your building’s interior, giving you reliable coverage so your family members and coworkers can get bars on their phones, wherever they are.

Cel-Fi products are the perfect fit for your environmentally conscious building. You’ll be able to benefit from increased energy efficiency and green credentials while ensuring your staff can contact clients and loved ones, access mobile internet on 3G, 4G and 5G, and stay connected.

Contact the team to discover how UCtel can improve your digital connectivity and communications. Get started

Final Thoughts

We are all surrounded by building materials blocking a mobile phone signal at work, at a shop, at home, etc. Using a signal boosting system, you can noticeably enhance your signal strength. If you want to know more about what materials block mobile signals and affect phone reception, reach out to the experts at UCtel.  

Blog Photos

Still have questions

Find answer below or contact us to ask more about UCtel

Which types of materials block mobile phone signals?

The most damaging phone and WiFi signal blocking materials are metal, concrete, and Low-E glass. However, brick, wood, and fibreglass insulation can also significantly deteriorate the quality of your calls.

Why do I have a poor phone signal from my home or office?

There are many reasons for experiencing poor phone signals such as unintentionally blocking the antenna with your hand, being in a crowded place, or being inside a building that is made of materials such as metal, wood, concrete, Low-E glass, fibreglass, and brick.

Can aluminium foil worsen a mobile phone signal?

Aluminium foil is a material that blocks mobile phone signals by up to 40dB. Even compared to concrete and brick, aluminium and metal materials, in general, affect your signal the most.

Does metal negatively impact phone signals?

Metal is one of the building materials blocking mobile phone signals the most. If you are in a building with metal elements, the signal might go down by 40dB.

Contact the team to discover how UCtel can improve your digital connectivity and communications.

Get started with UCtel

    Upload floor plans (PDF)

    No file selected

    Latest news from UCtel

    Read more

    This website uses cookies. By using this website you consent to our use of these cookies. For more information visit our Privacy Policy