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Comment by neolog | Hacker News Reader

Is it practical to put a Faraday mesh into the exterior walls of a house?

I've rented two houses that used chicken wire to bind the plaster to the lath. You could get a bit of cell service near the windows, but you needed a WAP in each room. Finding studs was a nightmare.

Yes, this kind of shielding in construction is well understood, people concerned about information leakage have been doing it for decades and made the specs public. (Also people suffering from perceived "eletromagnetic hypersensitivity")

Of course, any house totally shielded with a Faraday cage would look extra suspicious and thus receive closer scrutiny. You'd need most of the house to be non-shielded to act as a honeypot while maintaining a small shielded section of the house for "emergencies".

Who are you hiding from exactly?

Advertisers.

With 2 conditions; a) you would have to do it before closing up the walls and b) give up on radio.

Also, expect to have very strange windows. Of course, if visible light can pass through, that might be considered a flaw in your faraday cage so YMMV.

Personally, I'd like it if my devices knew what room I was in. Back in 2013, I'd started working on a home automation project with that goal in mind, but then all these closed source devices came out that were incredibly cheap and convenient and I haven't revisited the idea since.

I do look back with a bit of regret that more hasn't been done to push for reverse engineering these devices or somehow encouraging companies to open source their routers to support third-party operating systems, etc. We take for granted that we've open source smartphones and standard PC specifications when we don't yet have a standard that could let me run YouTube TV on my Echo Show 8, for example, or add lossless FLAC playback to my smart speaker...

I imagine window screen mesh connected electrically to the rest of your grid should work sufficiently (like the mesh on the microwave window)

>Also, expect to have very strange windows.

I have screens on my windows so I can have them open yet not have bugs wandering in and out - just pick wire mesh and ground it. Done!

You could just put antennae outside the walls like many houses/cars do.

I recently cut a couple holes in my house exterior through stucco. Like a sibling comment, that stucco was secured over some wire mesh. I can't remember how dense the mesh needs to be to block whichever frequencies would be used, but something like that would be commonplace and provide reasonable doubt.

There are different types of lathe used for plaster walls.

From chicken wire to mesh with 1/8, or less, inch rectangles.

I imagine the whole room would have to be covered with lathe. In good construction the lathe is covering every sq. inch of a room before the the base coat is put on.

Plaster wall are not typical anymore. Stucco is still used on exterior walls, but it usually just covers up ap the foundation, and might extent up the wall a few feet.

Plaster walls in a bathroom are the best walls though. The house I'm in has 1" thick plaster walls, and they hold up to a lot of abuse.

A well plastered plaster room would need screen on the door too, but that's doable.

If I was building a house, it would have stucco walls. Maybe only the exterior walls, and the ceilings? Then my signals could go room to room, but the world is locked out.

No one uses chicken wire, but it works just as well as the new smaller holed lathe sheets.

I still have no clue if modern sheets of lathe would act as a Faraday Cage?

I have fooled around with Faraday Cages, and tiny openings matter.

(I remember hearing about a guy who stole a vechicle with lowjack. He covered the vechicle with chicken wire, and the cell signal with through? He was caught.)

https://en.wikipedia.org/wiki/Tempest_(codename) might have useful info

Attic insulation ("radiant barrier") has a layer of aluminum, it can reduce EMF if joints overlap and are sealed with aluminum tape.

You also need to ground it (you should be doing this anyway for electrical safety).

Should there be a resistor (100K? 1M?) on the connection between shield and ground?

I am not an electrical engineer, but AFAIK no. You want your ground path to be the favored path, rather then say, a sweaty human hand if there's a short.

Trying to stop radio waves is sort of like trying to stop water. Any little crack or hole and it'll come through.

In addition to that, you might want/need to use only wired connections to your router and rip out any components that enable wireless.

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