I Think I Figured Out My Wireless Issues -- I Am Living in a Damn Faraday Cage

I have always had a couple of frustrations in my house.   First, we get awful, almost non-existent cell service from both Verizon and AT&T, despite living right in the middle of the city.  I always chalked this up to be on the outskirts of an area of town that until recently did not allow the construction of cell towers.

The other problem I have is trying to get a wireless signal through my house.  While the house sort of sprawls, it is U shaped with distances such that it should not be impossible to send signals from one side of the U to the other.   But it always has been hard, thus my investment in a commercial grade wifi system.

The other day I was watching a contractor cut a hole in the outer wall of my house, which is covered in stucco.  I hadn't really thought much about the home's construction -- it has some cinder block but mostly is just wood frame.  But watching the construction I had an epiphany.  The stucco was put on in the old way, over chicken wire.   I hadn't thought of this because none of the new stucco I have ever seen going on is done this way any more.   It turns out my whole house is covered in a big net of chicken wire.  Worse, I saw they had removed the stucco around one of the hose bibs and the chicken wire was wrapped around the metal piping, the same piping our house uses as a ground.  My whole house turns out to be covered in grounded chicken wire -- I'm living in a Faraday cage!

Obviously since the wire does not cover every surface (windows, roof, etc) and was not carefully constructed to be a Faraday cage, the effect is not perfect.  But I took some measurements.  Wifi signal strengths in the 2.4Ghz range dropped by about 7-10 db when passing through an interior wall but dropped between 20 and 30 db through my exterior walls.

So at least I have some idea, finally, of what might be going on.

32 Comments

  1. Joe Flamini:

    How lucky can you get?! I'm spending a fortune and a gazillion hours EMP-proofing my place. For cellular service, all you need is an external antenna connected to a bi-directional amplifier. Internally, a few interconnected wi-fi routers.

  2. Griz Hebert:

    Nothing beats hardwired APs, and lots of them. I use inSSIDer to fine tune the channels.

  3. McG:

    At our previous home, we used a carrier-sold femtocell that used our internet connection. Now I use a carrier that uses wifi, but Mrs. McG's carrier has much better signal inside this house.

  4. Ward Chartier:

    Well, at least you are nearly immune to electronic spying.

  5. Matthew Slyfield:

    The solution for your wifi issues then would be repeaters at the inside corners of the U, preferably arranged so the repeaters have line of sight between them.

  6. Kurt Droffe:

    Time for some funny experiments, I would say!:
    https://m.youtube.com/watch?v=Cgm4iegP-Og

  7. Stan Jackson:

    That's great! You don't need to wear foil on your head like I do!

  8. CapitalistRoader:

    Aluminum lath is still being used in new home construction in Denver. I rarely see plastic lath.

  9. Ray:

    You mention 2.4GHz, but I sure hope you're using 5GHz? Assuming you have the AP coverage (sounds like you do?).

    2.4 has better range, sure, but the spectrum is so saturated we've all but disabled it at work (~3000 or so users via Cisco WAPs) to force badly-behaving clients onto 5GHz instead.

    Also, not sure how you're extending your wifi network, but absent CAT5e/CAT6 in your home, you might look at using MOCA (assuming you don't also have DirecTV).

  10. rxc:

    At least you don't have a metal roof. They are everywhere here in Florida, because they are less likely to fly away during a storm or leak.

  11. jdgalt:

    For any Faraday cage, the greatest reduction in signal strength will be for wavelengths >= twice the largest dimension of any opening in the cage. The usual "chicken wire" has hexagonal openings maybe 2 cm across, thus most strongly affecting wavelengths >= 4 cm which are frequencies <= 7.5 GHz.

    This suggests that a grid with openings of 12 cm or larger would not affect wi-fi signals, or not nearly as much. It also suggests that a spy equipped to listen to frequencies above 7.5 GHz, such as the refresh signal to your picture tube, would be unaffected.

  12. southpaw0609:

    I use foil on my head to get better reception when I put the cell to my ear. Still experimenting aluminum vs tin. I'll get back to you

  13. Matthew Slyfield:

    Where do you even get tin foil anymore?

  14. marque2:

    Just a note here, it isn't a Faraday cage, and the grounding has nothing to do with the issue. What you have is a radiant barrier. The metal surface works like a mirror and reflects away most of the energy that is approximately twice the width of the holes of the poultry netting, about 5cm wide or greater. 2.3 gigahertz is approximately a 13cm wavelength, and 700 mhz is 46 cm so almost all the energy will be reflected off of your walls.

  15. marque2:

    I find the 2.4 works better than 5 in my neighborhood, because we live in houses, there are few other 2.4 ghz routers to interfere. Warren lives in a very nice community where the houses are spread out even more. I doubt he would have an issue. Apartment complexes are the worst. You almost are forced to use5ghz there, but sadly the routers seem to use fixed frequencies, so you don't get the spread like you would expect.

    Note too, some devices only work on 2.4. Alas, I have most of my computers on 2.4 because the wifi printer does not do 5. Also some of our cheaper cell phones (the ones the kids have) don't do 5.0 either.

  16. southpaw0609:

    You can find tin foil in hardware stores. As you noted, only Al foil is sold in grocery stores -- maybe food storage health code rules? -- just guessing.

  17. Craig:

    Yes. You could use an external antenna to boost your signal or a femtocell, which would give you a cellular signal inside your house from your router. https://www.komando.com/tips/296040/how-to-boost-cell-signals-inside-your-home/all

  18. Ray:

    All good points. Any potential interference could also be validated easily enough with spectrum analyzer tool for his smart phone.

    Anecdote: My sister has a microwave that, when running, kills a good chunk of the 2.4 spectrum... :-)

  19. marque2:

    Home microwaves run at 2.3 ghz - commercial in 900 mhz but they are suppose to be shielded. If she is getting severe phone interference she needs a new microwave. I wouldn't mess with a malfunctioning one.

  20. marque2:

    I cant find tin foil online at Amazon or home depot. Always directs me to aluminum "tin foil"

  21. EL_TED0:

    I have a room with a tin ceiling that gets terrible wifi. Had to add a Powerline adapter through the electric circuit to get internet there.

  22. Nehemiah:

    At least your electronic items might fare better when the EMP device goes off.

  23. marque2:

    When I was a kid I used to visit my grandparents in Germany. They had this display goodness at least 50 years now! My favorite part of the demonstration is when they take a piece of glass, must be 1.5 x 1.5 meters, and blast electricity from one side to the other. They show how the electricity crawls around the glass rather than through.

  24. johnmoore:

    Yep. When I was planning on building a house on my Paradise Valley lot, I looked into that, because I wanted my ham radios to work with indoor antennas. The house I have now (about 1 mi NE of your office) doesn't have wire in the stucco, and my scanners work just fine without outside antennae. Even so, my interior Wifi doesn't have that great a range (no outside walls involved). I don't know why.

  25. johnmoore:

    Why would you EMP proof your house?

    I say that as the author of an article warning about the danger of EMP: https://pjmedia.com/trending/2017/06/06/emp-commission-chair-warns-on-north-korean-emp/

  26. johnmoore:

    It is a Faraday cage, although not a very good one unless they intentionally bonded the chicken wire. You're right, though, that grounding has nothing to do with it (at those wavelengths).

  27. marque2:

    No, its not really, but no point in really getting into it for purposes of this discussion. Whether the energy is reflected (radiant barrier) or if you actually turned the homebintona Gaussian sphere Faraway cage is beyond the scope of the issue.

  28. CorkyBoyd:

    And they last a lot longer than shingles.

  29. CorkyBoyd:

    EMP is overrated as a danger. I was stationed near Pearl Harbor during Starfish Prime and listened to the short wave countdown from Johnston Island and switched to a VOA station in California with no loss of signal. There is far more EMP from a lightning strike on a power line near your home than a nuclear detonation 200 miles high.

  30. Joe Flamini:

    I lost a couple of video cameras a while back during a huge lightning storm. They were actually on the house, not remote w/"antennas".
    I live on a !#%$&! high-resistance rock in Virginia's Blue Ridge, and I've had to install electrolytic ground rods just to bring my grounds down from hundreds of ohms to tens of ohms. I've also added "halo" ground conductors to distort lightning-based "EMP" surges. BTW, great article!
    Call me sometime: 434-960-9259.

  31. Don:

    On the plus side, you have a chance of being able to watch dvds if the Norks decide to execute an EMP attack on the western US (well, once electricity is restored, about 6 months later).