http://fire.nist.gov/bfrlpubs/build97/art123.html - might be more
useful
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Gregory Forrest
404.Stone, W. C., "Electromagnetic Signal Attenuation in Construction Materials," NISTIR 6055, pp.202. ,NIST Construction Automation Program Report No. 3. October, 1997.
