What Is a Weird Thing to Use As Insulation?

Corn Cobs

• Corn cobs sometimes were used as insulation in the walls of old American homes. In Needham, Massachusetts, the dining room of the 1776 Josiah Lewis House can't be wired for electricity, because its walls contain corn cobs. Candlelight is still used to illuminate the room. Today, ground corn cobs are commonly sold as animal bedding. One company uses the material in sock-like door draft stoppers.

Denim

• America's cast-off denim pants have found new life as building insulation. In 2008, Levi Strauss & Co. shredded 200,000 pairs of old jeans to create insulation batting for the California Academy of Sciences in San Francisco's Golden Gate Park. Two years later, it insulated its own San Francisco headquarters with denim. Denim is touted as a renewable, nontoxic insulator versus fiberglass batting, which contains formaldehyde -- a known carcinogen.

Dirt and Tires

• Architect Michael Reynolds in the 1970s began building energy-efficient houses with walls made of old tires rammed with dirt. His Earthship Biotecture firm of Taos, New Mexico, used the technique to teach Haitians how to build inexpensive, earthquake- and hurricane-proof homes following the devastating earthquake in January 2010. Reynolds refers to the homes he designs as "earthships" and uses a number of disposables in their construction, including plastic bottles, another material he helped popularize as alternative insulation.

Mushroom Spores

• Mushroom spores are an ingredient of Eben Bayer's fire-resistant insulation board, which also contains water, flour and minerals. Bayer invented the product in 2007 while pursuing an undergraduate dual major in mechanical engineering and product design and innovation at New York's Rensselaer Polytechnic Institute. The mushroom spores create a tightly meshed material by digesting starch in the flour.