A floor is the walking surface of a room or vehicle. Floors vary from simple dirt in a cave to many-layered surfaces using modern technology. Floors may be stone, wood, bamboo, metal, or other material that can hold a person's weight.
Floors typically consist of a subfloor for support and a floor covering used to give a good walking surface. In modern buildings the subfloor often has electrical wiring, plumbing, and other services built in. Because floors meet many needs, some essential to safety, floors are built to strict building codes.
Where a special floor structure like a floating floor is laid upon another floor then both may be referred to as subfloors.
Special floor structures are used for a number of purposes:
Floor covering is a term to generically describe any finish material applied over a floor structure to provide a walking surface. Flooring is the general term for a permanent covering of a floor, or for the work of installing such a floor covering. Both terms are used interchangeably but floor covering refers more to loose-laid materials.
Materials almost always classified as floor covering include carpet, area rugs, and resilient flooring such as linoleum or vinyl flooring. Materials commonly called flooring include wood flooring, ceramic tile, stone, terrazzo, and various seamless chemical floor coatings.
The choice of material for floor covering is affected by factors such as cost, endurance, noise insulation, comfort and cleaning effort. Some types of flooring must not be installed below grade (lower than ground level), and laminate or hardwood should be avoided where there may be moisture or condensation.
The sub-floor may be finished in a way that makes it usable without any extra work, see:
Special tools used for flooring include:
There are a number of special features that may be used to ornament a floor or perform a useful service:
Wood floors, particularly older ones, will tend to 'squeak' in certain places. This is caused by the wood rubbing against other wood, usually at a joint of the subfloor. Firmly securing the pieces to each other with screws or nails will remove this problem.
Floor vibration is a particularly annoying problem with floors. Wood floors tend to pass sound, particularly heavy footsteps and low bass frequencies. Floating floors can reduce or eliminate this problem. Concrete floors are usually so solid they do not have this problem, but are also much more expensive to construct, and much heavier, resulting in further requirements regarding the structure of the building.
The flooring may need protection sometimes e.g. a gym floor used for a graduation ceremony. A Gym floor cover can be used to reduce the need to satisfy incompatible requirements.
Floor cleaning is a major occupation throughout the world. Cleaning is essential to prevent injuries due to slips and to remove dirt. Floors are also treated to protect or beautify the surface. The correct method to clean one type of floor can often damage another, so it is important to use the correct treatment. See floor cleaning for more details..
Ground-level slab floors are prepared for pouring by grading the base material so that it is flat, and then spreading a layer of sand and gravel. A grid of rebar is usually added to reinforce the concrete, especially if it will be used structurally, i.e. to support part of the building.
Floors in woodframe homes are usually constructed with joists that are centered no more than 16 inches or 40 centimeters apart, according to most building codes. Heavy floors, such as those made of stone, are more closely-spaced. If the span between load-bearing walls is too long for joists to safely support, then a heavy crossbeam (thick or laminated wood, or a metal I-beam or H-beam) may have to be used. A 'subfloor' of plywood or waferboard is then laid over the joists.
In modern buildings there are numerous services provided via ducts or wires underneath the floor or above the ceiling. The floor of one level typically also holds the ceiling of the level below (if any).
Services provided by subfloors include:
In floors supported by joists utilities are run through the floor, by drilling small holes to go crosswise. Where the floor is over the basement or crawlspace, they may instead be run under the joists, making the installation less expensive. Ducts for air conditioning (central heating and cooling) are large and cannot cross joists or beams, thus they are typically at or near the plenum, or come directly from underneath (or from an attic).
Pipes for plumbing, sewerage, underfloor heating and other utilities may be laid directly in slab floors, typically via cellular floor raceways. Maintenance of these systems can be very expensive however, requiring the opening of concrete or other fixed structures. Electrically heated floors are also available, and both kinds of systems can also be used in wood floors as well.