Do Walls Affect Wi-Fi?

A Wi-Fi connection can seem like magic, streaming the Internet to your computer or mobile device with no wires and connecting you to the rest of the world, but that doesn’t mean the technology is without its limitations. Just like any other radio signal, Wi-Fi signals can be absorbed or reflected by certain materials, reducing their strength. The walls of buildings are no exception. However, you can take steps to reduce the impact of structural elements on your wireless signal.

Wireless devices are essentially miniature radio transceivers, capable of transmitting and receiving radio signals. Wi-Fi connects your devices to the Internet by transmitting data packets using ultrahigh radio frequencies. Wireless routers operate on either the 2.4-GHz or 5.8-GHz band, with 2.4 GHz offering greater range and 5.8 GHz offering more channels of operation, which results in less interference from adjacent signals. As with any radio signal, some materials can absorb the radio signals, a situation known as attenuation.

An attenuated Wi-Fi signal can result in undesirable performance from your network connection. If the signal is weakened to the point where reception is marginal, data packets can be lost as the signal fades in and out, or the connection can be lost entirely. Weakened signals can also cause connection speeds to slow to a crawl and make streaming music, videos and games choppy or completely unplayable.

Signal strength and attenuation are measured in decibels, which work on a logarithmic scale. A loss of 6 dB is a 50-percent reduction in signal strength, and a 12-dB loss is a 75-percent reduction in signal strength. A typical 3.5-inch brick wall, 2 inches of marble and a 1.75-inch solid wood door will all attenuate a 2.4-GHz Wi-Fi signal by 6 dB. A single-pane exterior window will cause a 7-dB reduction in signal strength, and a double-pane window will add 13 dB of attenuation. An interior hollow wall of 4 inches causes 5 dB of attenuation, a 6-inch hollow wall causes a 9-dB loss, and a 5-inch solid wall causes a 14-dB signal strength loss.

Since the typical household interior poses significant attenuation to Wi-Fi signals, it’s important to maximize every bit of signal possible to get the most out of your connection. Placing your router in a central location offers the most even coverage of the entire house with relatively even signal fall-off throughout all corners of the building. Keeping the router out in the open, as opposed to tucked in a cabinet or at the back of a shelf spreads the Wi-Fi signals evenly. Houses with interior brick or cinder block wall construction may require more drastic measures such as external antennas or setting up Wi-Fi repeaters.