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1. a flat bottom surface in or on any structure
2. Nautical the bottom, or the lowermost framing members at the bottom, of a vessel
3. Politics that part of a legislative hall in which debate and other business is conducted
4. Politics the right to speak in a legislative or deliberative body (esp in the phrases get, have, or be given the floor)
5. a minimum price charged or paid
6. take the floor to begin dancing on a dance floor


The lowest surface of a room or structure, which can be a division between one story and another made up of other elements, or a homogeneous material. It is the base plane of any room or structure, and is usually characterized by a flat surface or a series of flat surfaces at different levels.

floating floor

The floor is separated from the rest of the building by supporting it on sleepers or a built-up structural system, to provide sound insulation or space for high-tech flexible electrical service, independent of wall locations.

hollow-tile floor

A reinforced-concrete floor that is cast over a formwork of hollow clay tile blocks, the concrete filling the voids between the tiles.

laminated floor

A structural floor that is constructed using a continuous series of lumber set on edge and nailed together.

raised floor

A false floor, which provides a space for cables or ducts above the structural floor, floor sections are usually supported on short, adjustable peg columns.



a horizontal interior enclosed member of a building. Floors are used between stories, between the upper story and the attic, in basements, between the first story and the basement, and over passageways. Floors, which are supported by walls and other vertical elements, bear the weight of people, equipment, partitions, and furniture and transfer the load to the supports. At the same time, floors lend horizontal structural stability to a building as stiffening diaphragms.

In modern construction, a floor usually is a complex structure consisting of a load-bearing frame (slabs or beams), layers of insulation, a flooring, and, sometimes, a ceiling (a separate component of the floor). In multistory buildings, the floor frame is most often made of reinforced concrete. Wooden floor frames are used in smaller masonry and wood buildings. Wooden frames are generally used in regions rich in timber. Reinforced-concrete floor elements (precast, cast-in-place, or a combination of both) are manufactured from normal weight, silicate, or lightweight concretes (including expanded-clay and perlite concretes), as well as from various combinations of the three concretes (in multilayer floor frames).

The design of reinforced-concrete floor selected is determined by the uses of a building, the nature of the load the floor will bear, and the site conditions. Floors may consist of several slabs set on joists, girders, or trusses; slabs spanning in two directions supported by walls or partitions; or a single slab having an area equal to that of the room. Floor slabs may be solid, hollow-core, ribbed (waffle type and slabs with prestressed edge beams), or corrugated.

In mass housing construction, precast hollow-core porous slabs are most commonly used. The longitudinal hollow cores are mostly round or oval in cross section.

Floors must satisfy requirements of strength, rigidity, durability, fire-resistance, and sound insulation. Some floors, mainly in industrial buildings, must be impermeable to gas and steam and resistant to aggressive media. It is particularly important that the floors of residential and public buildings have good sound insulation. This may be achieved by carefully sealing joints and seams, using several layers of sound-insulating materials, or using special acoustic construction (for example, using two parallel slabs separated by a layer of air, using an elastic bearing beneath the flooring, or constructing a suspended ceiling). Ceilings made of sound-absorbent materials are used in rooms with particularly demanding acoustic requirements.

Today, the basic trend in the design and construction of floors involves the use of large prefabricated composite slabs. The design of floors of combined precast and cast-in-place construction is undergoing further improvement, as is the design of floors made of a single reinforced-concrete slab, which are erected by the lift-slab method.


Konstruktsii grazhdanskikh zdanii, 2nd ed. Edited by M. S. Tupolev. Moscow, 1973.
Konstruktsii promyshlennykh zdanii. Edited by A. N. Popov. Moscow, 1972.

Z. A. KAZBEK-KAZIEV [19–1139—4]



a structural element of a building that bears the effect of the movement of people and loads, as well as static loads of furniture and machinery in a room. The structural, operating, sanitary, and decorative requirements of a floor are determined by the purpose and nature of the room. The floors of public buildings must be durable, wear resistant, elastic, and smooth but not slippery. They must have low heat assimilation, be easy to clean, have a pleasant appearance, and match the interior decoration. In damp areas the floors must be water-resistant and waterproof; in fire-hazardous rooms the floors must be fireproof. In industrial buildings, greater requirements are specified for the surface of floors in terms of their capacity to resist mechanical effects (abrasion, impact, puncturation) and, for some industrial processes, the effects of chemicals or heat.

In modern construction, most floors are multilayer. They consist of a foundation (the ground or a structural floor) and the flooring, which is directly subjected to the operating effects. The floor may also include sound and heat insulation and waterproofing. In the installation of a floor on ground level, the flooring is installed on a bedding course to distribute the load on the ground. (A bedding course generally is not used in floors above ground level.) To smooth out the surface of the foundation and give it the necessary rigidity, a layer of cement mortar is applied above the base layers. Then the finished floor is laid.

Floors are distinguished according to their type of flooring. Monolithic, or continuous, floors are made of cement concrete, asphalt concrete, xylolith, earth, or clay. Materials in sheet or roll form are used to make floors (linoleum, synthetic pile coverings, ultrahard wood fiberboard). Some floors are inlaid with parquet, boards, stone blocks, ceramic tile, clinker, and metal plates. The best floors are seamless mastic floors and floors made of polymer roll materials (linoleum, Relin), which are installed over a base of heat and sound insulation.


Tishchenko, I. I., and O. M. Maksimova. Ustroistvo polov: Spravochnik. Moscow, 1972.
Belousov, E. D., E. M. Linde, and A. S. Bykov. Poly zhilykh i obshchestvennykh zdanii. Moscow, 1974.



The bottom, horizontal surface of an enclosed space.
The rock underlying a stratified or nearly horizontal deposit, corresponding to the footwall of more steeply dipping deposits.
A horizontal, flat ore body.
(mining engineering)
Boards laid at the heading to receive blasted rocks and to facilitate ore loading.
(naval architecture)
One of a series of vertical plates extending across the bottom of a ship at right angles to the center line and forming part of the bottom framing of the hull.


1. In a room, the surface on which one walks.
2. A division between one story and another; one story of a building. Also see blind floor, counter-floor, earth floor, finish floor, ground floor, lowest floor, threshold floor, underfloor, upper floor.
References in classic literature ?
At sight of the two struggling upon the floor the newcomer raised his voice in a shriek of rage.
The protruding tongue and the popping eyes proclaimed that the end was near and a moment later the red robe sank to the floor of the room, the curved blade slipping from nerveless fingers.
The blade struck at the junction of the neck and torso and with such force as to completely decapitate the Wieroo, the hideous head dropping to the floor and the body falling forward upon the Englishman.
Upon the floor at his feet was the dead body of a strange man.
He had never heard of Sherlock Holmes or he would have lost no time in invoking the aid of that celebrated sleuth, for here was a real mystery: An old woman--an invalid who had to be carried from the ship to her room in the hotel--and a handsome lad, her grandson, had entered a room on the second floor of his hostelry the day before.
And so the forest grew until today it covers almost the entire floor of the valley except for the open space where the city stands.
The old woman led Bertha Kircher to an adjoining apartment in the floor of which was a pool of water.
For what seemed hours to the distraught girl she paced the floor of her apartment, awaiting the final summons to the presence of the mad king.
As the question passed through his mind, he noticed for the first time something lying on the floor near the head.
Without a sound he died and lunged forward to the floor.
You will not speak with Tara, Princess of Helium, though doubtless the blood of many Manatorians will drench the floors of the women's quarters before you are slain.
Struck in mid-air, a trifle of a flying machine, all its delicate gears tangled and disrupted, Cocky fell to the floor in a shower of white feathers, which, like snowflakes, eddied slowly down after, and after the plummet-like descent of the cat, so that some of them came to rest on her back, startling her tense nerves with their gentle impact and making her crouch closer while she shot a swift glance around and overhead for any danger that might threaten.