System floors are divided into raised floors (regulated in DIN EN 12825) and hollow floors (regulated in DIN EN 13213).
The base course of finished hollow floors, whether poured on site or installed in dry construction, forms a continuous homogeneous layer with a flat bond. The finished floor covering can also be laid as a broadloom by the subsequent flooring trade, regardless of the hollow floor grid. The cavity of a hollow floor can only be accessed non-destructively via fixed recesses, e.g. in the form of inspection openings or raised floor routes inserted in sections.
In contrast, with a raised floor, all areas below the base course remain freely accessible at all times, as the base course, including the wear layer, consists of modular elements with a mostly square basic grid, which is also taken up by the floor covering, which is usually already applied to the raised floor elements at the factory.
Numerous different floor coverings are possible with both systems, such as HPL, parquet, elastic and textile floor coverings, which are glued on element by element to raised floors and must be approved by the manufacturer for use on raised floors. The top of the base course can also represent the finished wear layer, e.g. as a powder-coated metal surface. In the case of a raised floor with a metallic base layer, perforations are also possible, which, for example, in a clean room enable a particularly low-turbulence vertical displacement flow with soil vapour extraction via the air-permeable (because perforated) base layer and the intermediate floor area, or a spring air floor, in which the system floor supplies the (air-conditioned) fresh air to the room.
Source: bauwion
