Things That Don't Mix: Homeowners, Chicken Wire and WiFi
Many residents of old homes in San Francisco homes have chicken wire inside their walls that was put there 70 years ago instead of drywall. Now, nearly a century later that chicken wire is preventing homeowners from getting WiFi or cellphone signals.
The problem dates to before drywall became a popular building material in the 1950s. Before then, construction crews usually made walls out of plaster applied to lath, a base structure that holds it up. Often, lath in Victorian and Edwardian-era homes was made of wood stapled with chicken wire, a cheap fencing material that also doubles as lightweight support. The problem occurs in other cities too, but San Francisco has an unusually dense collection of old homes and gadget lovers.
"It's the old bumping into the new," says Mike Scott, a technical media manager for network gear maker D-Link Corp., who fields many questions about chicken wire. "How were people 70 years ago supposed to know that we were going to have all of these wireless gadgets?"
Many factors can disrupt wireless networks, including steel girders, air-conditioning vents and water-filled objects -- including humans and pets. But even with its many holes, chicken wire creates a particularly powerful metal shield.
Physicists call it a "Faraday cage" -- a metal structure that impedes electricity and waves -- because the fencing is the perfect size to catch waves generated by 2.4-gigahertz Wi-Fi networks. "It turns out that chicken wire is almost perfectly the right wavelength of a Wi-Fi signal," says Karl Garcia, who sets up Google Inc.'s free Wi-Fi efforts. "It acts just like a solid piece of metal."
A Faraday Cage, eh? Naturally, that makes us forget all about the hazards of chicken wire to ponder anew the role of Dr. Daniel Faraday on Lost. Dr. Michael Faraday (who got the Faraday Cage named after him, among other things) was a physicist that lived from 1791 – 1867 who specialized in electromagnetism and electrochemistry. He was known for his experiments, although so far as we know he did not experiment with time travel.
So, to sum up: if you have an old home and can't get a WiFi signal, look into the whole chicken wire in the walls thing. And Lost returns Tuesday, February 2nd on ABC.
