Fiber-cement board
Current fiber-cement products are direct descendants of asbestos-cement building products that were widely used until the 1970's, but contain no asbestos. Fiber-cement products are formed from a mixture of cement and wood fiber (which constitutes 8-10% of the material). Fiber-cement board products are typically 5/16" thick. . Fiber cement plank and lap siding is available in a variety of widths and finish textures. Panels are available in 4' x 8', 9', or 10' sheets. Some fiber-cement panel manufacturers offer a stucco finish in addition to smooth or wood-grain textures. Several fiber-cement manufacturers now offer accessory trim, soffit, and fascia elements. Fiber cement materials can be worked with woodworking tools, and should be finished with an alkali-resistant paint, although some can be used unpainted if handled carefully to avoid scratching. Most fiber-cement products come with a 50-year manufacturer's warranty, due to the relative newness of these products true longevity is unknown. It is expected that fiber-cement products will need less frequent repainting than wood products, since it expands and contracts less with fluctuations in moisture.