A raised computer floor, elevated floor system and access floor system are all the same thing: a raised structural floor placed on the reinforced concrete slab of a building.
Vertical pedestals are laid out and adhered or bolted to the concrete substructure and then panels are placed on top to complete the flooring in the desired finish.
The gap between the panels and the elevated floor can vary from 3 inches to 48 inches (and more if needed) according to the applications it is needed for. Besides the laying of the cabling for the electronics, data and communications systems, many raised computer floors also incorporate cooling and heating systems.
The panels (2X2 feet) consist of a cement or wood core which is strengthened by steel or aluminum. They can be found in all the popular types of floor finishes including carpet, ceramic tile, laminates, linoleum, rubbers, stone and vinyl.
Areas suited for raised computer floor applications
- Computer rooms and IT spaces
- Exhibit areas
- Open office layouts
- Training and conference centers
- Other office areas which encompass office support systems
Areas inappropriate for a raised computer floor
- Directly on a slab on grade location because of the lack of protection from moisture, heat etc.
- Food preparation areas and kitchens where food and liquid spills are highly likely.
- Laboratories are also high risk areas for chemical, biological and spills from plumbing.
- Fire stairs and all stair landings,
- Rooms that hold mechanical equipment like chillers, boilers ad air handling equipment. Besides containing moisture this equipment is also heavy,
- Loading areas, central storage rooms, garbage rooms, UPS areas, electrical generator areas and child care areas are also not suited for raised computer floor applications.
Minimal structural requirements for a raised computer floor
- Minimum impact load of 2.25KN
- Should support 11.86KN/m2
- Carry point load of 4KN
- Rolling load of 2KN at 1000 passes
Minimum specifications of raised floors for seismic conditions
- Bolts are required for fixing the pedestals in any seismic zone 3 and higher. The pedestal structure must also be suitable for seismic zones by meeting the specifications required.
- In seismic zones 3 and above, the bracing pedestals used must have a length greater than 12 inches.
Other considerations to be taken into account in the construction of an access floor
Cushions may need to be installed on the pedestals in areas where impact sounds may be generated by walking or rolling loads. The main reason for this is that if hollow panels are used they do not insulate impact sounds as well as panels with light concrete, cement like materials or wood.
Other sounds may also be transmitted from under the floor to other areas and the raised computer floor is often provided with sound transmission attenuation.
Vibration transmissions from machinery or transformers are not something that can be addressed by the manufacturer of the raised floor.
Advantages of a raised computer floor
- In situations where there is a problem of shear transfer across the diaphragm of an area, raised computer floors are a solution.
- In high seismic regions they reduce the cost of construction.
- This type of flooring offers waterproofing from small spills for the area it is to be used in.
- The heating and cooling of a building with an access floor is more efficient if it is used with HVAC systems.
- In the event of a fire, it will be suppressed between floors.
- Raised floors offer acoustic isolation.
- Lateral resistance and durability is increased for taller multi-story buildings in areas with extremely high wind. It is essentials that the structure also has a concrete roof otherwise the flooring alone won’t offer the protection needed.
Raised flooring offers many applications and also has many advantages for building structures. The main reason why computer raised flooring is still preferred is that it offers the possibility for cabling to be out of sight, while still allowing for easy access for cleaning, maintenance and the add-on of new systems without entailing costly maintenance. Power and data outlets can also be interspersed throughout the area as needed and these are also easy move if changes are needed.