Raised Floors

A raised floor or access floor, are types of floor that provide an elevated structural floor above a solid substrate (often a concrete slab) to create a hidden void for the passage of mechanical and electrical services. They are widely used in modern office buildings, and in specialized areas such as command centres, IT data centres and computer rooms where there is a requirement to route mechanical services and cables, wiring, and electrical supply. Raised/Access Flooring can be installed at varying heights from 100mm to heights above 1500mm to suit services that may be accommodated beneath. Additional structural support and lighting are often provided when a floor is raised enough for a person to crawl or even walk beneath. Many modern computer and equipment rooms employ an underfloor air distribution to ensure even cooling of the room with minimal wasted energy.

Conditioned air is provided under the floor and dispersed upward into the room through regularly spaced diffuser tiles, blowers or through ducts directed into specific equipment. Automatic fire protection shutoffs may be required for underfloor ventilation, and additional suppression systems may be installed in case of underfloor fires.

This type of floor consists of a substructure of adjustable-height supports called pedestals that provide support for removable floor panels, which are 600×600 mm in size. The height of the pedestals is dictated by the volume of cables and other services provided beneath, but typically arranged for a clearance of at least 150mm.

The panels are made of a steel panel with a wooden internal core. Panels may be covered with a variety of flooring finishes to suit the application such as carpet tiles, high-pressure laminates, marble, stone, and antistatic finishes for use in computer rooms and laboratories. To remove panels, a tool with a suction cup on the end (referred to as a "floor puller", "tile lifter", or "suction lifter") is used. A hook-and-loop lifter may be used on carpeted panels.

Additional accessories for the access floors are available such as ventilation grills and brush grommets. Brush grommets are used bring cables from the floor void into the office environment and can be helpful in improving air ventilation under the flooring. The brush also acts as a protection guard preventing small objects or dust finding its way into the floor void.