One of the most common questions I get from people interested in Faraday cages for electronics is: "Don't Faraday cages need to be grounded?"
This is a question I've investigated. With the help of technical consultants, I'd like to give you the short answer - Maybe!
It depends on the size. A small Faraday cage will not need grounding You can see this in the videos we show on our site - when our shield is tested, it rests on a plastic bin.
A large Faraday cage may need that grounding. When you get to a room or building size cage, there is the possibility that the EMP wave can electrically saturate the cage without good grounding. And, there is also a safety reason to ground - If someone touched an ungrounded cage of that size, there could under the right conditions be a discharge through that person. Not good.
Now you know what to say, the next time someone asks YOU this question! Help pass the word on.
If you have any thoughts, please, feel free to comment below!