Unlike dozens of cabins, two have survived the massive Caldor Fire as it ravaged through the wooded Phillips Tract close to Sierra at Tahoe. Among the spared homes is the one which appeared to be covered in aluminum foil which was termed by some as a massive baked potato.
But wrapping structures with the aluminized wrap is already known as a fire protection strategy.
These wraps can prevent fire from catching the structure by blocking huge burning embers; preventing the building from touching the blaze directly; and foiling the extreme heat from causing fire through reflecting thermal radiation from nearby burning structures.
In fact, a couple of layers of this wrap can prevent up to 92 percent of convective heat and 96 percent of the radiation, said Fumiaki Takahashi, Case Western Reserve University’s engineering professor who has done laboratory experiments to test the wrap.
“It is effective for protecting structures for a short period while the wildfire front passes — 5 to 10 minutes —but longer protection would be needed to prevent structure-to-structure ignition,” the professor told The Chronicle.
The foil can be wrapped around a structure through staples and is available in rolls.
A San Diego-based company Fizerat that sells the wrap said that the material is made of aluminum on the outside. On the inside, it is made of woven polyester threads and fiberglass. A high-temperature adhesive is used to laminate the material, according to the company’s founder Dan Hirning.
“It’s not tin foil,” he said. “It’s so perfectly engineered after all these years.”
While the foil-wrapping strategy appears to be a fresh strategy, the founder said it was used in 1988 in the Yellowstone National Park. Firefighters, during that time, are deployed to prevent fire from reaching a historic building. The fire crew had to escape and thought of wrapping the structure with a part of their protective fire shelters.
“They think that’s part of what saved them,” he said.