Suspended ceilings with a metallic top layer can form a continuously closed level, but also an open soffit, whose components merely filter the view into the ceiling cavity. Accessibility to the ceiling cavity is made possible via inspection flaps or by loosely attached, movable or foldable top layer elements. In addition to meeting fire protection or sound insulation requirements, these suspended ceilings also offer a wide range of design options for the ceiling soffit as a space-forming component. Their substructure usually consists of load-bearing profiles that are suspended from the raw ceiling at the desired height via individual hangers, and there are systems that span from wall to wall in a self-supporting manner.
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Possible applications: The possible applications for suspended ceilings with a metallic top layer are diverse and depend heavily on the respective product. They are often used in the following new construction and renovation projects:
Requirements: The technical and design requirements that can be placed on suspended ceilings with a metallic top layer depending on the project are just as diverse as the possible applications:
Requirements and test methods for suspended ceilings are specified in particular in DIN EN 13964.
Fire protection: In certain installation situations, suspended ceilings must meet the fire behaviour of the building materials used (e.g. flame retardant, no burning droplets/drops), and/or fire resistance. In the case of ceiling cladding/suspended ceilings, this is differentiated according to whether it is suitable for fire exposure
is to be interpreted. Furthermore, in the case of a fire load from the underside, a distinction must be made as to whether the required fire resistance is met by the suspended ceiling alone or in conjunction with the raw ceiling above. For more information on the fire resistance of suspended ceilings, see Lexicon article ► Fire resistance of ceiling cladding/suspended ceilings.
Partition wall connection: In order for a ceiling cladding/ suspended ceiling with a requirement for fire resistance to be connected to a rising partition wall as a room-enclosing component in accordance with the approval, at least the same fire resistance must be proven for the partition wall as for the suspended ceiling .
According to the Model Pipeline System Directive (MLAR), pipeline systems in the false ceiling area of escape routes must be fastened in a fire-safe manner. In the event of a fire, the suspended ceiling must not be stressed by burning or falling pipe parts.
Resistance to wind stress: In accordance with DIN EN 13964, suspended ceilings inside the building must be able to absorb wind loads by means of suitable constructive measures if they are to be expected, e.g. through open doors and windows. They must remain stable and unharmed and, in particular, must not fail or collapse. Top layers that tend to lift off in critical areas such as entrance halls, in the corners and upper floors of multi-storey buildings and near open windows and doors must be clamped in place in accordance with DIN EN 13964. In the case of larger building openings, e.g. large doors, suspended ceilings in open entrances or multi-storey car parks, the resistance to wind pressure and suction must be demonstrated separately.
Module dimensions according to DIN EN 13964: Usually, module dimensions for suspended ceilings are based on a multiple of 100 mm, submodules on a multiple of 50 or 25 mm. This applies equally to all top layers, i.e. to square grid ceilings as well as to longitudinal panel ceilings.
Lateral disconnection/connection of the suspended ceiling: The lateral connection of suspended ceilings to rising walls is usually carried out with an L-bracket, which is visible on the underside with the top layer components and is butt-butted in the corners in accordance with DIN 18340 VOB C:
Appropriate
connection profiles also allow the formation of a shadow gap possible:
An open end is also possible for many suspended ceilings, taking into account the manufacturer's specifications, whereby the individual top layer components are bordered by U-shaped profiles:
Lighting: A wide range of recessed ceiling luminaires can be integrated into suspended ceilings with a metallic top layer, the size of which is matched to the ceiling grid used. Elongated formats especially for panel ceilings or rectangular/square formats, e.g. for coffered or lattice/honeycomb ceilings, can be integrated exactly into the module dimensions of the suspended ceiling , without unsightly cuts of the adjacent top layer components. Especially with metal design ceilings, there are creative possibilities for lighting design.
Ceiling mirror: When planning suspended ceilings with a metallic top layer, the creation of a ceiling mirror is usually useful or necessary. The ceiling mirror is a vertical projection of the ceiling soffit as a reflection downwards. The ceiling mirror must contain all the information that is important for the production of the suspended ceiling , including all attached, surface-mounted and built-in parts. This enables an overall planning of the suspended ceiling , including the consideration of laterally adjacent components, height differences and technical elements such as recessed luminaires and ventilation outlets. It often makes sense to define axes, e.g. in the middle of the room or to door/window openings, which determine the position of built-in parts across all trades. For more information, including an example of a ceiling mirror, see lexicon article ► Ceiling mirror.
Substructure: A substructure of suspended ceilings with a metallic top layer usually consists of basic profiles (supporting profiles), which are installed at intervals in accordance with the approval or the technical rules. Often, the basic profiles form a grate together with transverse additional connection profiles. The basic profiles are attached to the raw ceiling above by means of hangers. An exception is self-supporting ceilings, in which the top layer components span freely from wall to wall without ceiling fastening up to the maximum span specified by the manufacturer, if, for example, the quality of the existing raw ceiling does not allow the sub-ceiling to be attached to the raw ceiling in accordance with the approval. Lattice or honeycomb ceilings are suspended directly from the raw ceiling without additional basic profiles. Hangers are available in galvanized wire, spring steel, threaded rods, aluminum or sheet steel. Fastening in the ground must be carried out with fasteners approved for the respective building material (e.g. dowels, setting bolts). In the event of fire stress in the space between the ceilings, the fasteners also require appropriate approval for this purpose.
Construction height: The construction height of the suspended ceilings results from the thickness of the top layer, the height of the substructure and the suspension. For the clear dimension in the false ceiling, e.g. as an installation space for technical cables, the thickness of the top layer and the height of the substructure must be subtracted.
Sound insulation: Closed suspended ceilings usually significantly improve sound insulation to the building levels above. However, it is not possible to make any general statements about the improvements, as too many boundary conditions, in particular the design of the flanking components and the raw ceiling, play a role. The exact extent of the improvement must therefore be examined, calculated and, if necessary, evaluated in accordance with VDI 3755 in each individual case, taking into account the specific installation situation.
Sound absorption of acoustic ceilings: The installation of acoustic ceilings improves the so-called reverberation times of a room, which depend not only on the volume of the room, but above all on the sound absorption capacity of the room surfaces. Reverberation times that are incorrectly or not taken into account for the respective use can lead to the unusability of the room in certain rooms, e.g. gymnasiums, if, for example, communication is unreasonably difficult due to excessively long reverberation times.
Important information for hearing in rooms is contained in DIN 18041, which divides rooms into groups A and B. Group A includes rooms in which voice communication must be ensured over medium to long distances (e.g. conference rooms, banquet halls, community halls, classrooms and conference rooms, lecture halls, group rooms in kindergartens and day-care centres, day-care centres for the elderly, sports halls and swimming pools). Group B are rooms in which voice communication takes place at a short distance (e.g. sales rooms, restaurants, bank counters, consultation rooms in doctors' offices, offices, operating theatres, treatment rooms, hospital rooms, workrooms, public traffic areas, libraries and reading rooms).
According to DIN EN ISO 11654, the sound absorption capacity is divided into six classes A (highly absorbent, > 90% sound absorption) – E (low absorbency, 15 – 25% sound absorption). In the assessment according to VDI 3755, a class F (reflective, ≤ 10% sound absorption) is also provided.
The manufacturer specifies the sound absorption coefficients and sound absorption classes for the individual acoustic panels. Some manufacturers also offer free room acoustics calculators online for the uncomplicated calculation of reverberation times.
Curved ceiling surfaces: Curved ceiling surfaces can also be produced with metal suspended ceilings, especially with panel ceilings. There are systems
Both systems thus enable concave, convex or wave-shaped ceiling soffits.
Damp rooms: The damp room suitability of suspended ceilings with a metallic top layer must be specified by the manufacturer, assigning the suspended ceiling system to one of the load classes according to DIN EN 13964, see also lexicon article ► Suspended ceiling, load class according to DIN EN 13964. Especially ceilings in rooms with increased humidity and with corrosive impurities, e.g. salt or chloride pollution in a swimming pool, require increased corrosion protection of all metal components, depending on the load class and material, e.g. by anodizing, electrolytic galvanizing, coil coating or organic coating.
Ball impact safety: If ball impact protection is required, e.g. in gymnasiums, it must be checked whether the selected suspended ceiling system is suitable and approved for this, e.g. in accordance with DIN 18032.
of assembly: Annex A to DIN EN 13964 contains (informative) requirements for the construction site that must be met at the start of assembly, unless otherwise specified by the manufacturer:
Flatness/design tolerances: Permissible design tolerances and the required flatness of suspended ceiling systems are regulated in DIN EN 13964 (Tables 3/ 4/ 5 and Annex A.5.2).
Gated top layer components: According to DIN EN 18340 VOB C, cut top layer components such as metal cassettes or panels, e.g. in connection with rising walls, must be stiffened in such a way that they neither curl at the open edge nor sag further in the surface than permissible according to DIN EN 13964.
DIN 18041, Audibility in Rooms; Requirements, recommendations and notes for planning
DIN 18340, VOB Procurement and Contract Regulations for Construction Services - Part C: General Technical Contract Conditions for Construction Services (ATV) - Drywall construction work
DIN EN 13964, Suspended ceilings - Requirements and test methods
DIN EN ISO 11654, Acoustics - Sound absorbers for use in buildings - Assessment of sound absorption (ISO 11654)
VDI 3755, Technical Rule, Sound Insulation and Sound Absorption of Suspended Suspended Ceilings
Source: bauwion
