You can use it on either side of the wall, but it will not stand up to weather.
Emil
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Could you use that on the outside walls? And then the waves would be absorbed rather than be repelled. But.....
would some still get through because it is absorbing them? Loni
A very convenient material which can be used to line walls, and ceilings is
the Laminated Microwave Absorber
http://www.lessemf. com/fabric. html#259
Absorber installation is much simpler than for a reflector as you don't have
such a big concern about leakage points. Just cover a large area (maybe
75-90% of the surface).
Emil