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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 ?
So through various yawning holes there slipped to the floor below--to one room hams, to another forequarters, to another sides of pork.
When I realized this, I was so angry that I had to sit down on the floor and take hold of something to keep from lifting the roof off with an explosion of opinion.
There was something laying on the floor in the far corner that looked like a man.
Leaving the basement story of the house, which was entirely devoted to the servants' offices, they ascended to the first floor, and entered the long corridor, with which Magdalen's last night's experience had already made her acquainted.
Soon after the planks in the floor sprang up as before, and the woman came up, dressed in white, with the iron belt and chain.
As he sunk to the floor I wheeled around with my back toward the nearest desk, expecting to be overwhelmed by the vengeance of his fellows, but determined to give them as good a battle as the unequal odds would permit before I gave up my life.
Then he was dragged backward upon the floor, a heavy body fell upon him, powerful teeth fastened themselves in his jugular, his head whirled in the sudden blackness which rims eternity--a moment later the ape rose from his prostrate form; but Condon did not know--he was quite dead.
Then, methought, the air grew denser, perfumed from an unseen censer Swung by Angels whose faint foot-falls tinkled on the tufted floor.
And the Raven, never flitting, still is sitting, still is sitting On the pallid bust of Pallas just above my chamber door; And his eyes have all the seeming of a demon's that is dreaming And the lamp-light o'er him streaming throws his shadows on the floor; And my soul from out that shadow that lies floating on the floor Shall be lifted--nevermore!
They descended a dark stone staircase, at the floor of which Symon pressed a button and a door opened on a dark room, or, rather, a room which had an instant before been dark.
Aunt Em, badly frightened, threw open the trap door in the floor and climbed down the ladder into the small, dark hole.
This first floor, containing Mrs Brooks's best apartments, had been taken by the week by the d'Urbervilles.