These can be defined as ceilings which are fixed to a framework suspended from main structure thus forming a void between the two components. The basic functional requirements of suspended ceilings are:
- They should be easy to construct, repair, maintain and clean.
- So designed that an adequate means of access is provided to the void space for the maintenance of the suspension system, concealed services and/or light fittings.
- Provide any required sound and/or thermal insulation.
- Provide any required acoustic control in terms of absorption and reverberation.
- Provide if required structural fire protection to structural steel beams supporting a concrete floor.
- Conform with the minimum requirements set out in the Building regulations and in particular the regulations governing the restriction of spread of flame over surfaces of ceilings and the exceptions permitting the use of certain plastic materials.
- Design to be based on a planning module preferably a dimensional coordinated system with a first preference module of 300mm.
Classification of Suspended Ceiling
There is no standard method of classification since some are classified by their function such as illuminated and acoustic suspended ceilings others are classified by the materials used and classification by method of construction is also very popular. The latter method is simple since most suspended ceiling types can be placed in one of three groups:-
- Jointless suspended ceilings.
- Panelled suspended ceilings.
- Decorative and open suspended ceilings.
Jointless Suspended Ceilings
These forms of suspended ceilings provide a continuous and jointless surface with the internal appearance of a conventional ceiling. They may be selected to fulfil fire resistance requirements or to provide a robust form of suspended ceiling. The two common ways of construction are a plasterboard or expanded metal lathing soffit with hand applied plaster finish or a sprayed applied rendering with a cement base.
Panelled Suspended Ceilings
These are the most popular form of suspended ceiling consisting of a suspended grid framework to which the ceiling covering is attached. The covering can be of a tile, tray, board or strip format in a wide variety of materials with an exposed or concealed supporting framework. Services such as luminaries can usually be incorporated within the system. Generally panelled systems are easy to assemble and install using a water level or laser beam for initial and final levelling. Provision for maintenance access can be easily incorporated into most systems and layouts.
Decorative and Open Suspended Ceilings
These ceilings usually consist of an openwork grid or suspended shapes onto which the lights fixed at, above or below ceiling level can be trained thus creating a decorative and illuminated effect. Many of these ceilings are purpose designed and built as opposed to the proprietary systems associated with jointless and panelled suspended ceilings.