Which Building Materials Can Block Wi-Fi Signals?

Are you curious why a part of your home, or even an area just outside the house, has poor Wi-Fi reception? It could be due to the material used for the wall, or other physical barriers that block or weaken Wi-Fi signals.


Infographic: Wi-Fi Signal Loss By Building Material (also described in the article below)

Worst Signal Loss: Concrete

Concrete, with and without metal reinforcement, is one of the worst building materials for wireless signals to pass through, but masonry block and bricks can also be serious barriers for Wi-Fi.

Least Signal Loss: Plywood and Drywall

Plywood and drywall come close to zero signal loss in tests.

By the Numbers

The numbers in the graphic and the following table are based on the findings in extensive experiments performed by the US National Institute of Standards and Technology.

Material Loss in decibel at 5 GHz
Concrete (203 mm) 55.1581
Reinforced concrete 53.7989
Brick-faced concrete 39.8953
Brick-faced masonry block 32.6320
Concrete (102mm) 26.0008
Brick 15.2806
Masonry block 14.9250
Lumber 3.2778
Glass 0,0688
Drywall ~0
Plywood ~0

The full report is called “Electromagnetic Signal Attenuation in Construction Materials”, NIST Construction Automation Program Report No. 3.