Wool is the most expensive and luxurious fiber in everyday use for carpets. It has advantages over synthetics but costs considerably more. Because of its price and some other drawbacks, wool carpets represent only about 1 percent of U.S. market [source: Doityourself.com]
Wool fiber carpets are made from the hair of sheep, with New Zealand wool considered the finest. Some wool rugs are made from the hair of goats, llamas or alpaca. Wool is naturally resilient. Because the sheep's hair grows in a spiral, the fibers have an excellent "memory" when twisted into tufts. Wool fiber is durable and the carpets can last 60 years or more if properly cared for [source: The Flooring Lady]. The fiber is easy to dye and comes in rich colors.
But wool is high-maintenance. It usually requires a professional cleaner to do a careful job. The fiber has some stain-resistance, but wool can absorb protein-based stains like meat juice and blood. It's also sensitive to dye stains like tea, coffee and wine. Fortunately, because of the way the wool fibers bend light, it tends to hide dirt.
Wool's resistance to fire is another plus. While synthetic carpets can melt and burn, wool chars but does not burn. It can be a good choice if cigarette burns are a concern. Because it's a natural fiber, wool is a sustainable resource. It has good insulating properties. It absorbs and releases moisture, serving as natural humidifier. It resists dust mites, which can aggravate allergies.
Keep in mind that wool is almost always going to be more expensive than other fibers. Also, it can create a static charge, especially in dry weather, so -- like nylon -- you won't want it near your computer. Some people are allergic to wool.
Wool has low resistance to abrasion, so it can wear down in high-traffic areas. After long use, wool carpet can develop bald spots. It's also subject to damage by moths -- though most wool carpets are now moth-proofed before you buy them. Wool holds 10 times its weight in moisture, making it susceptible to mildew and mold. It can develop an odor and shrink if it gets wet.
Wool is more popular for rugs -- which cover only a part of a room -- than for wall-to-wall carpets. A wool area rug gives luxurious accent to a formal room. You won't want to use it for high-traffic areas like hallways. And it's not the best if you have kids or pets.
In the next section, you'll read about a fiber that looks like wool but is much less expensive.