Terra cotta is one of the oldest tile materials around, dating back before the birth of Christ, when it was sun-dried rather than oven-fired. People often use it, glazed or unglazed, when they want a rustic, weathered look.

"Quality terra cotta will last forever," says Dave Gobis, executive director of the Ceramic Tile Education Foundation, "but unfortunately it's very difficult to assess the quality, even for tile professionals." Buy only from a seller whose reputation you trust; even then, you may encounter problems.

For practical uses, "terra cotta can be enhanced by the seal you put on it," says Daniel Dixon, a California-based tile construction expert. "It is highly recommended that it be sealed, and if it's for kitchen use, you must seal it particularly well."

Install Yourself? No
Best Uses: Flooring, countertops, walls
Pros: Beauty, longevity when well-made
Cons: Wide variations in quality
Price Range: $3–$7 per square foot