Siding or wall cladding is the protective material attached to the exterior side of a wall of a house or other building. Along with the roof, it forms the first line of defense against the elements, most importantly sun, rain/snow, heat and cold, thus creating a stable, more comfortable environment on the interior side. The siding material and style also can enhance or detract from the building's beauty. There is a wide and expanding variety of materials to side with, both natural and artificial, each with its own benefits and drawbacks. Masonry walls as such do not require siding, but any wall can be sided. Walls that are internally framed, whether with wood, or steel I-beams, however, must always be sided.
Most siding consists of pieces of weather-resistant material that are smaller than the wall they cover, to allow for expansion and contraction of the materials due to moisture and temperature changes. There are various styles of joining the pieces, from board and batton, where the butt joints between panels is covered with a thin strip (usually 25 to 50 mm wide) of wood, to a variety of clapboard, also called lap siding, in which planks are laid horizontally across the wall starting from the bottom, and building up, the board below overlapped by the board above it. These techniques of joinery are designed to prevent water from entering the walls. Siding that does not consist of pieces joined would include stucco, which is widely used in the Southwestern United States. It is a plaster-like siding and is applied over a lattice, just like plaster. However, because of the lack of joints, it eventually cracks and is susceptible to water damage. Rainscreen construction is used to improve siding's ability to keep walls dry.
Wood siding
Left: Wood shingles; Center: Clapboard; Right: Board and batten.
Wood siding is very versatile in style and can be used on a wide variety of building structures. It can be painted or stained in any color palette desired.
Though installation and repair is relatively simple, wood siding requires more maintenance than other popular solutions, requiring treatment every four to nine years depending on the severity of the elements to which it is exposed. Ants and termites are a threat to many types of wood siding, such that extra treatment and maintenance that can significantly increase the cost in some pest-infested areas.
Wood is a moderately renewable resource and is biodegradable. However, most paints and stains used to treat wood are not environmentally friendly and can be toxic. Wood siding can provide some minor insulation and structural properties as compared to thinner cladding materials.
Wood siding in overlapping horizontal rows or "courses" is called
weatherboard
(British English), or bevel siding which is made with beveled boards, thin at the top edge and thick at the butt.
In colonial North America,
cedar
.
Drop siding
Jointed horizontal siding (also called "drop" siding or novelty siding) may be shiplapped or tongue and grooved (though less common). Drop siding comes in a wide variety of face finishes, including Dutch Lap (also called German or Cove Lap) and log siding (milled with curve).
Vertical boards
Main article:
Board and batten
Vertical siding may have a cover over the joint: board and batten, popular in American wooden Carpenter Gothic houses; or less commonly behind the joint called batten and board or reversed board and batten.
Wooden sheet siding
Plywood sheet siding is sometimes used on inexpensive buildings, sometimes with grooves to imitate vertical shiplap siding. One example of such grooved plywood siding is the type called Texture 1–11, T1-11, or T111 ("tee-one-eleven"). There is also a product known as reverse board-and-batten RBB that looks similar but has deeper grooves. Some of these products may be thick enough and rated for structural applications if properly fastened to studs. Both T-11 and RBB sheets are quick and easy to install as long as they are installed with compatible flashing at butt joints.
Stone siding
Slate shingles may be simple in form but many buildings with slate siding are highly decorative.