The concept of radiofrequency (RF) shielding is simple: simply put a barrier between the source of the radiation and the area you want to protect. But keep in mind that in many ways, RF behaves like light and can reflects off of some surfaces… working its way around any shield which is less than a complete enclosure.

Image that you are outdoors on a sunny day. You set a large mirror on a stand above your head. The attenuation for the mirror is very high, perhaps 120 dB or more, so basically no light comes through the mirror. If leakage was not an issue, you would be in total darkness. We all know this is not the case. Leakage from the sides easily illuminates the shaded area. Granted, the amount of illumination is less than standing in full sunlight, but the attenuation is nowhere near 120 dB. Maybe more like 20 dB. Furthermore, using a shield with even better attenuation will not yield any more benefit.

To achieve a high level of shielding, you must control leakage VERY carefully. Gaps under doors, joints between shield sections, and even pinholes from sewing shielding material can permit these high frequency signals to penetrate. You need to create a “complete” enclosure. Any part that is not shielded is a leakage point.

In addition, it is critical that you remove RF sources which are inside the room. Check with an RF meter for cordless phones, wifi routers, laptops, baby monitors, etc. An RF meter will also guide and evaluate the effectiveness of your shielding installation.

Start by shielding the windows

Windows will most certainly permit RF to enter the room. Think about the type of windows you have and whether or not you plan to open the windows. There are 3 basic approaches to shielding windows:

1) apply a shielding film to the glass itself. ScotchTint and RadioClear are two good choices.

2) create an indoor screen which fits into the window opening. Use Copper Wire Mesh or VeilShield

3) create a shielded curtain, or curtain liner. Naturell, ArgenMesh, SaniSilver, and Soft&Safe are good choices. If you need transparency, choose High Performance Silver Mesh, Daylite, or VeilShield.

Shield the walls and ceiling
Painted surfaces are easily shielded with CuPro-Cote or Y-Shield paint. This includes trim and doors. Be sure to caulk and gaps or cracks prior to painting so that you have a continuous, unbroken painted surface. You can paint over the shielding paint with any color of latex paint to achieve any appearance you like. You could also use a shielding fabric such as Nickel Copper RipStop or AL60 behind the wall. Attach these materials directly to the studs before installing the drywall. Pay attention to whether or not a vapor barrier is desired in your location.

How about the floor?
Floors are best shielded during construction. The subfloor can be painted, or a shielding fabric layer can be applied before the final floor surface is installed. If the floor in already installed, you can lay shielding fabric, and cover it by a large area rug or sheet linoleum.

Remember to control leakage, such as the gap around the door, switch plates, mounted light fixtures, vents and so on. Contact us if you need advice.