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.

Special floor structures

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:

• Balcony, a platform projecting from a wall
• Floating floor, normally for noise or vibration reduction
• Glass floor, as in glass bottomed elevators
• Nightingale floor makes a noise when an intruder walks on it
• Raised floor, utilities underneath can be accessed easily
• Sprung floor, improves the performance and safety of athletes and dancers

Floor covering

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:

• Earthen floor adobe or clay floors
• Solid ground floor cement screed or granolithic

Carpet

Carpet is a floor covering woven or felted from natural or man-made fibers. Fitted carpet is attached to the floor structure, extends wall-to-wall, and cannot be moved from place to place. An underlay can extend carpet life and improve comfort.