if you were to build a room to block out radio waves with cheap materials, how would you do it? layers of foil lining the room? how many layers would it take? what percentage would be blocked out by the method you suggest? thanks in advance!
Sheet metal and most wall insulator will block some of radio waves. If you have a charging device and connect it to your sheet metal, it will observe the radio wave by a lot.
Layers of foil would block some of it. A layer of sheet copper would be a lot better. You have to cover the entire room, floor, ceiling walls window, etc. Joints should be soldered for a complete seal. Special care has to be taken on any heating/AC input, and any power or data connections, and around doors and windows. These all can get complicated with special filters for power and data connections.
