What Building Materials Block Mobile And WiFi Signals?

If you have ever suffered from signal problems on your phone or have a weak WiFi signal, the building materials around you could be to blame. This is particularly true when your phone works well in areas outside your home, but get little to no signal once you step inside. In this situation, it is clear that something in the house is blocking the signal, but what is it? There are actually a number of different materials in your home that could be blocking your signal and making it hard to use your phone or the internet.

While it is impossible to state for certain what is causing the problem, you can get an idea of what the problem material could be. The figures mentioned in this article will be mobile signal strength attenuation, but WiFi signals are attenuated similarly. The 802.11 standard used for WiFi offers distinct radio frequency ranged and each range is divided into multiple channels. Without getting into too much detail on frequencies and channels, it is important to note that the mobile signal information will provide an estimate for WiFi signal as well.

Poor Mobile Signal

Clear Glass Panes

Most people believe that clear glass fixtures such as the window are the best place to get a signal. These clear areas are ideal when you want more light, but they can reflect signal away from the house and bounce it around. This is particularly true when you are dealing with double-glazed windows. Triple-glazed windows will reflect and bounce the signal even more than the double-glazed windows.

The windows that deflect the most signal will be low emission ones. They have been designed to keep the elements out of your home and keep it warm or cool depending on the season. If you are looking to improve your mobile reception, you need to open the window to get the full benefit. The blockage on windows can reach -4db.

Insulation And Sheetrock

While sheetrock has lower blocking abilities when it comes to signal if the signal is already weak this material will be able to block it completely. Signals for 3G, 4G and 5G will be the same as a radio signal and this results in a fluctuation of -2db. Sheetrock rooms which are closed and not part of an open floor plan will cause more problems with signal than those in an open layout.

Fibreglass insulation in the attic and walls will also disrupt the signal if it is thick enough. This can be surprising for some people due to the porous nature of the insulation. If you have foil-faced insulation such as foam boards and fibreglass batts, radio frequencies will be blocked. The interior walls of your home may also use denser material which causes another -2db drop. This results in sheetrock and insulation being able to cut off your signal before it gets into your home.

Solid Wood And Plywood

Many residential properties will have a structure and framework made primarily of plywood. The problem is that this material is able to reduce 3G and 4G networks by up to -6db. 5G networks face greater disruption at -9db. It is important to note that this reduction will vary depending on the thickness of the plywood and how it has been compressed. When the plywood is damp or wet, the signal loss will increase to -20db, but this reduction is the least of your worries if the plywood in your home is wet.

Solid wood in your home such as the wood used for flooring will add to the blocking power of the plywood. Finishing’s on floors, doors and decking will offer a natural look to your home but they will also block the signal. All wood will slow down your signal and the thicker the wood, the greater the disruption will be. Softwoods such as pine will not cause too great a reduction, but you could still face a loss between -5db to -12db. While there are many solutions to poor coverage, a mobile signal booster is by far the best option you have if you want to reliably boost your coverage.

No Mobile Coverage


Brick is a study material when facing the elements and it is also one of the top signal blocking materials. The thickness of the brick is the first factor that slows down the signal. The second factor is the mortar between the bricks which does not allow any signal either. Bricks will also have supplementary materials to allow shelves, electronics and sheetrock to be added. The thickness of the wall, when combined with the density of the material, will cause a signal reduction of -28db.


When looking at building materials that block signal, metal is going to be the top disrupter. Metal roofs, interior metal and metal studs will all slow down the signal in your home. Metal can be aesthetically pleasing on your building, will be durable against the elements and will help with the routing of electricity away from the walls, but it will also route your signal away.

Most houses that have a metal roof will have a weak signal. This is true even for buildings that are located in areas with a very strong signal. Metal roofs can drop your signal strength to as little as -32db to -50db. When your signal reaches this point, your home is essentially classed as a dead zone.


This is one of the many reasons why buying a signal booster is a must in today’s society. Having great coverage and internet connection is so important and if you don’t have those then you will fall behind!