Do you have poor coverage in parts of your home? Here are some examples of how much Wi-Fi signals are weakened when passing through walls.
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.
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. Plywood and drywall come close to zero signal loss in tests.
Signal Loss by the Numbers
The numbers in the graphic above and the table below are based on the findings in extensive experiments performed by the US National Institute of Standards and Technology.
| Material | Attenuation in decibels at 5 GHz |
|---|---|
| Concrete (203 mm) | 55,1581 |
| Reinforced concrete | 53,7989 |
| Brick-faced concrete | 39,8953 |
| Brick-faced masonry block | 32,6320 |
| Concrete (102 mm) | 26,0008 |
| Brick | 15,2806 |
| Masonry block | 14,9250 |
| Timber | 3,2778 |
| Glass | 0,0688 |
| Drywall | ~ 0 |
| Plywood | ~ 0 |
These figures are taken from the report “Electromagnetic Signal Attenuation in Construction Materials”, NIST Construction Automation Program Report No. 3 from the National Institute of Standards and Technology.
Geek’s Corner
You can read the full research report here: http://fire.nist.gov/bfrlpubs/build97/art123.html
Article by Jorunn Danielsen
