Recycling Old Carpet Into Insulation

Roughly four billion pounds (1.8 billion kg) of old carpeting are landfilled each year. Comprised of different materials—nylon, polyester, latex backing, etc.—the stuff is inherently difficult to reprocess back into carpet (see EBN Vol. 6, No. 6). So how ’bout simply shredding the stuff and turning it into a fiber insulation material? That’s exactly what entrepreneur Tom Deem wants to do.

Deem is an inventive sort of guy who works in a plumbing supply store in Philco, Illinois. When he wasn’t cutting pipe or finding the right plumbing fixtures for customers a few years ago, he thought a lot about the huge quantity of old carpet making its way into landfills. In 1993 he came up with the idea of turning old carpet into loose-fill insulation for attic applications. So he bought a used brush chipper and tried shredding samples of carpeting. That worked pretty well—the chipper broke the backing apart and left a fluffy fiber with a density of about 2 lb/ft3 (32 kg/m3). The product was not unlike cellulose insulation, and he found that it could be blown into attics using cellulose-blowing equipment.

Over the years, Deem had the good fortune of getting to know building scientist Bill Rose (with the Small Homes Research Council at the University of Illinois). He gave Rose a sample to carry out some quick thermal testing, and the stuff achieved a respectable R-3.3 per inch (RSI-0.6)—about the same as most fiberglass batt insulation and somewhat better than loose-fill fiberglass, though not quite as high as cellulose.