or you could just paint it

Paint your house to shield your WiFi

As wireless networks have proliferated, computer security companies have come up with increasingly complex defenses against hackers: password protection, encryption, biometrics. Insulating the interior of a house, apartment or office from radio-wave interference is a simpler concept that has yet to become a popular consumer strategy, but a new product called DefendAir from Force Field Wireless could change that.

Available online at forcefieldwireless.com, the product is a latex house paint that has been laced with copper and aluminum fibers that form an electromagnetic shield, blocking most radio waves and protecting wireless networks. Priced at $69 a gallon and available only in flat gray (it can be used as a primer), one coat shields Wi-Fi, WiMax and Bluetooth networks operating at frequencies from 100 megahertz to 2.4 gigahertz.

Two or three coats will achieve the paint's maximum level of protection, good for networks operating at up to five gigahertz. Force Field Wireless also sells a paint additive ($34 for a 32-ounce container, enough to treat a gallon of paint) and $39 window-shield films.

Harold Wray, a Force Field Wireless spokesman, said the paint must be carefully applied. "Radio waves find leaks," he said.

It should be applied selectively, he said, because it might hinder the performance of radios, televisions and cell phones.