Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sdd.hp.com!hplabs!hpl-opus!hpnmdla!charlies
From: charlies@hpnmdla.hp.com (Charlie Sallberg)
Newsgroups: sci.electronics
Subject: Re: room shielding
Message-ID: <7380030@hpnmdla.hp.com>
Date: 24 Apr 91 17:48:03 GMT
References: <1991Apr13.031643.3772@world.std.com>
Organization: HP Network Measurements Div, Santa Rosa, CA
Lines: 21


 We recently built a "low-cost" shielded room here at HP for an antenna
 testing range, using two layers of foil-backed wallboard on both sides
 of the metal 2x4 framing (4 layers of foil total). The seams of the foil
 were taped with 4-inch wide aluminum tape. The seams of the two layers
 on each side of the wall were also staggered. 
 The ceiling was done the same way, and for the floor, sheet aluminum was
 laid down, again taping all seams between panels and where the floor meets
 the wall.

 I measured > 60 dB of shielding effectiveness at 1, 5, & 10 GHz for these
 walls.

 Handling the penetrations for lighting, other electrical, doors, etc. is
 the trickiest part of any shielded room, but others have already made some
 good suggestions for some of those.

 I believe the foil-backed wallboard is generally available anywhere, as I
 think it's designed to provide a vapor barrier for normal construction.

 Charlie