Traditional clay tile is both durable and noncombustible. If you use the barrel-shaped variety, make sure openings (especially those over the eaves) are sealed so flying embers can't penetrate your roof. The Roof Tile and Slate Company sells both new and salvaged Ludowici clay tile. About $500 per square (enough tile to cover 100 square feet), not including installation. The Roof Tile and Slate Company,
Carrollton, TX; 800-446-0220.