Individual horizontal siding strips that overlap each other are often called clapboards. Cedar is a popular (though pricey) choice because it is naturally insulating, stable, and easy to work with. It has some natural preservatives but will rot if exposed to moisture for long periods; the lighter-color sapwood is more susceptible than the darker heartwood. Beveled cedar clapboards come in various grades. Widths range from 4 to 12 inches; 6-inch-wide boards are the most common size. The term "beveled" refers to the fact that the boards are wider at the bottom end than the top. Better boards are knot-free ("clear") or have only tiny knots. Clapboards with vertical grain (evidenced by closely spaced and fairly straight grain lines) may be called "quartersawn" and are less likely to warp and shrink than boards with flat grain (evidenced by widely spaced and wavy grain lines). To ensure against rot, order primed or prestained cedar.Channeled and Beveled Cedar
Channeled and beveled cedar has a lip that slips over the piece below, simplifying installation. The channels make the boards more stable. You may also choose cedar-beveled siding with decorative edges.Preprimed Wood Siding
Preprimed wood siding may be made of Scandinavian pine or another light-color wood. The wood itself is not as rot-resistant as cedar, but the priming is a great help.Fiber-Cement Lap Siding
Fiber-cement lap siding comes in various widths and is usually not beveled. Some types are smooth; others have a wood-grain texture. This material is inexpensive and easy to work with. Once installed and painted, it is difficult to distinguish from wood siding. It resists cracking but will swell if exposed to moisture for prolonged periods.Primed Hardboard and Textured OSB
Primed hardboard and textured OSB (oriented-strand board) are the least expensive options. They are also easy to work with and will last a long time if kept well sealed with paint. However, if a bare surface is exposed to moisture, it will swell quickly.Tongue-and-Groove or Lapped Horizontal Siding
This type of siding is available in wood only. Car siding fits together in a shiplap arrangement, with the top piece lapping over the lower piece. Cedar tongue-and-groove, or drop, siding may have a decorative curved surface at the top. Installation is easier than for standard lap siding because you can simply stack them on top of each other without measuring the exposure.