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Today I want to talk about WiFi signals and how easily they penetrate walls.
During my EMF consults, I hear it pretty often:
“Well the WiFi router is in the office, so that shouldn’t be causing my sleeping problems (since my bedroom is far away from the office).”
That, unfortunately, is just not true. And I want to explain why…
How Does WiFi Work?
Living without WiFi technology is almost impossible in this digital age.
From powering social media connections to bridging lines of communication, WiFi sure has become an efficient and much-needed tool these days.
But have you ever thought about how it works – and what that means?
WiFi is short for Wireless Fidelity and is synonymous to Wireless Local Area Network or WLAN.
This technology operates through the use of radio waves in order to send signals between different devices.
To be specific, WiFi receives and transmits information using the Gigahertz range (GHz).
Interestingly, the frequency at which WiFi works is almost the same as a microwave.
When heating up food in your microwave, the appliance uses 2.450 GHz while sending data operates within the 2.412 to 2.472 GHz range.
That right there is where the problem lies.
Let’s talk more about that…
Is WiFi Radiation Harmful?
Knowing how WiFi works is the key to understanding how it can be harmful.
As we’ve discussed, WiFi technology operates via radio waves, which emit a form of energy known as electromagnetic radiation (EMR).
The problem with this is that radiation exposure, even at low doses, can cause health complications over a long period of time.
The health problems linked to radiation can range from minor discomforts such as headache and fatigue to more severe things such as tumors, cancers, and insomnia.
The extent of that harm is also affected by a number of factors.
First, WiFi routers are usually kept on, all day and all night, seven days a week. This means you and your family are constantly under radiation exposure.
Second, your router isn’t the only source of radiation – neighboring houses and establishments probably have it, too.
Finally, the EMF that WiFi emits can pass through the walls of your house, making the two previous factors a big deal when it comes to accounting for the amount of radiation around you.
How Does WiFi Travel?
Now let’s look more into how these radio waves allow for WiFi to travel to different parts of a house, especially through walls.
I’m sure you’ve noticed if a WiFi router is located in your living room, you can still access its connection from many rooms away.
However, if someone turns on the light in the living room, that light source doesn’t pass through the wall like WiFi does.
Why is that so?
Radio waves are made up of bigger wavelengths than the size of the atoms of a wall, allowing them to pass through.
Light waves, on the other hand, have smaller wavelengths compared to the wall’s atoms, preventing them from penetrating walls.
Of course, this concept is dependent on the atomic structure of the wall.
Clearly, if the wall is made of glass, light passes just as easily as WiFi does.
Materials whose electron structure is transparent for radio waves allow for wireless technology to operate.
Other wall structures may have properties of electron shells that don’t allow specific types of electromagnetic waves to pass.
What Is the Maximum Range of WiFi?
It depends on a number of things. The first factor is the kind of wireless router you have.
Using routers that have high power capacity can cover more range for wireless connection.
However, this factor also depends on the power radio of the connecting device (ie your cellphone or laptop).
If the paired device has a low power radio, the wireless link won’t be strong even if the router has a wider range.
The second factor is the kind of 802.11 protocol that is used.
For example, the 802.11 ac standard can only operate in short distances but can offer the highest throughput (aka how much data is transferred from one point to another in a given amount of time).
Meanwhile, the 802.11b provides the best range but at the expense of low throughput and speed.
Lastly, the WiFi range also varies depending on the physical environment where the router is placed.
WiFi signals may weaken depending on the path it has to go through.
If it needs to penetrate materials like walls and multiple floors, it will lose strength.
What Can Interfere with WiFi Signals?
You’ve probably noticed the farther your device is from the router, the weaker the signal gets.
This happens because WiFi doesn’t have an endless range.
Some circumstances cause the WiFi signal to grow weak because of path loss. Here are a few factors that affect WiFi signal strength:
1. Physical Obstructions
Solid items such as walls, doors, and floors can decrease the range of a WiFi signal.
Normally, WiFi passes through easily, but if the objects are made out of tougher or thicker materials, these things can block the signals.
For instance, there will be a big problem with the WiFi signal if your walls are made of cement, metal, or certain stones.
When surveying your home or office, just remember that metallic bodies are structures that best absorb WiFi signals.
This is why you usually lose connection when you’re inside the elevator.
Rooms with tinted glass are also slightly better shielded because this type of glass has metal constituents in it.
Generally speaking, it’s rooms that are constructed with non-porous materials that tend to block WiFi signals the best.
Another factor affecting WiFi strength is radio interference with the frequency range.
Other WiFi networks and appliances that use a similar wireless channel can also disrupt your signal.
Microwaves, wireless phones, baby monitors, digital satellites, and neighboring routers can be a source of interference.
If those devices are in the same area as your router, the chances of interference are higher.
What Materials Will Block a WiFi Signal?
If you want to create a home where WiFi DOES NOT have “free range,” here are some of the materials you want to use:
Metal blocks WiFi signals most effectively because it’s a conductive material. Radio waves will essentially “bounce off” or be reflected.
The best materials for WiFi shielding include silver, copper, and stainless steel.
Certain Types of Insulation
Insulation can still interrupt signals even though it’s porous.
If the design of the fiberglass insulation is thick enough, it can potentially cut your reception.
Considering the density of bricks and the mortar between them, they’ll decrease the amount of radio frequency radiation that enters your home from the outside – but not much.
Does WiFi Go Through Concrete Walls?
No. Concrete is another material that blocks WiFi signals pretty effectively. WiFi signals and cellular reception drop significantly when they encounter concrete obstructions.
For more specific info, check out my article on WiFi radiation protection advice.
Frequently Asked Questions
Does WiFi bounce off walls?
Most walls are made with drywall, which is pourous and non-conductive, so no, WiFi does not “bounce” off of walls.
If, however, your walls have metal sheeting in them, then yes, the radio waves would be reflected.
Can 5 GHz go through walls?
Yes, but not as easily and thoroughly as 2.4 GHz signals. That’s because 5 GHz can’t travel as far, and they’re more easily affected by obstacles like floors and walls.
Certified EMF Expert, Chief Editor & Researcher at Beat EMF. I’m in charge of testing all the products and sorting through the duds to deliver effective EMF solutions for your family. Learn more about me here.