USES:Its used to conceal varied service lines- structural features , open pipes and wiring, and air conditioning ducts.It gives more options to use special lighting systems such as cove lighting, wall washers, floating effects and so on.False ceiling can be used to give thermal insulation for a given space.Besides, it also creates an effective sonic system especially in auditoriums, cinema halls or recording studios.
TYPES OF SUSPENDED CEILINGS
EXPOSED OR LAY-IN GRID
CONCEALED GRID FOR
METAL CLIP-IN TILES
OPEN CELL CEILINGS
BESPOKE METAL CEILINGS
METAL FURRING SYSTEMS
Very basic and economic cost of False Ceiling comes out to Rs. 50 Rs 200 per sq. ft (square feet) . If you add some creative designs and material quality cost goes up. Designs that gel well with rest of the room.
Plaster of Paris ( POP ) is being used since long long time. Since last few years, Gypsum boards are used a lot. Previously simple wood was used, now good quality Ply is commonly used.
The suspended ceiling was originally developed to conceal the underside of the floor above and to offer acoustic balance and control in a room.
The acoustic performance of suspended ceilings has improved dramatically over the years, with enhanced sound absorption and attenuation. This is sometimes achieved by adding insulation known as sound attenuation bats (sabs), more commonly referred to as "sound bats", above the panels to help deaden sounds and keep adjacent rooms quieter.
EXPOSED OR LAY-IN GRID
A system where the grid is visible and into which panels are laid. The grid is finished in colours to harmonise or contrast with the panels.
Panels are manufactured from a variety of materials including mineral/rock fibre, glass fibre, plasterboard, calcium silicate, glass reinforced gypsum, perlite, wood, steel and aluminium. Panels are available in a variety of sizes to suit the modular features of the grid system. The more common being 1200 x 600, 600 x 600 and 500 x 500mm.
Grid systems are, generally, an inverted T design, with a table (exposed face) width of 15 or 24mm. They are rolled from galvanised steel strip with a finished facing of painted steel or aluminium. Grid systems may also have an exposed face that is rolled to a profile or have a profiled aluminium section applied.
Extruded aluminium exposed grid systems are also available.
The various components clip together to form square or rectangular modules to receive infill panels.
Panels have, most commonly, square or simple rebated edges, but some propriety products may have other edge details. A considerable number of face patterns and colours are available.
Many panels are designed for wide usage and have good general performance. Panels are also available with enhanced features, offering increased sound absorption, sound attenuation, heat insulation, resistance to humidity, etc.
Exposed grid suspended ceiling systems can contribute to passive fire protection.
The system is rapid to install and can provide a high degree of access to the ceiling void.
Concealed Grid (For Tiles Other Than Steel/Aluminium)
A system where, after the tiles are installed, the grid is not visible.
The system most commonly comprises galvanised steel Z sections fixed with clips to a primary network of galvanised channel sections.
Systems using inverted T sections (similar to those described under Exposed or lay-in grid ) may also be appropriate for specific manufacturer s tiles.
Tiles are manufactured from a variety of material, including mineral/rock wool, glass fibre, perlite cast plaster and wood.
Edges may be kerbed (slotted), back-cut or tongued & grooved to receive the Z or T section.
The butting edges of the tiles may be square or bevelled to create a V joint feature.
Common sizes of tiles are 300 x 300 and 600 x 600.
Concealed grid systems require an extremely high standard of workmanship to achieve a satisfactory installation.
SEMI-CONCEALED GRID :
A system where the grid is visible in one direction only.
The exposed grid sections would generally be a 24mm T , as described under Exposed or lay-in grid . The concealed components may be similar T section, Z section (usually 32mm deep) or a special deep cranked Z .
As the grid components do not interlock spacer bars must be used to prevent the exposed tee sections spreading allowing panels to fall.
This system is designed to support planks tiles that are 300mm wide and 1200, 1500, 1800 and up to 2500mm long.
The exposed sections support the shorter edges.
Planks are manufactured from a variety of material, including mineral/rock wool, glass fibre, wood, steel and aluminium.
The short edges are square cut and the long edges may be kerbed (slotted), back-cut or tongued and grooved to receive the Z or T section.
Planks manufactured from steel or aluminium will, generally, not require the longitudinal (concealed) components.
The butting edges of the planks are usually bevelled to create a V joint feature, but may be square metal versions may have a separating foam gasket.
Semi-concealed systems can offer access to the void above the ceiling, but, if required on a regular basis, care should be exercised in the selection of plank material.
Marking and drilling in primary ceiling.
fix the perimeter angle section to the walls at the desired levels.
Suspend the intermediate c channel from the ceiling at the desired height with soffit cleat.( soffit cleat spacing=1200mm, intermediate channel spacing=450/600mm)
Suspend the main frame ceiling section from the intermediate section with connecting clips at 600mm c/c.
Screw the panel onto the frame work.
the electric cables and service ducts ore laid as per design before panels are screwed.
For final finishing panel can be painted or polished.
Suspended ceiling is a secondary ceiling which is hung below the main ceiling.
Also referred as a drop ceiling, T-bar ceiling, false ceiling
Used for concealing the underside of the floor above
Used to offer acoustic balance and control in a room & improve insulation.
Consists of a grid work of metal channels in the shape of an upside-down "T
Grid work are suspended on wires from the overhead structure
Grids modular size = 600x600mm
Each cell is filled with lightweight "tiles" or "panels" which simply drop into the grid.
Tiles can be selected with a variety of materials
Installation Of Suspended Ceiling:
Install splayed wires at 3.6m on center in four directions.
Provide adjustable compression struts, at center of splayed wires, and attach to the structure above.
Provide ceiling tile clips.
Provide 25mm minimum separation between the ceiling system and the enclosing walls
This separation is called seismic separation
Standard grid module systems should not be more than 1.5 m in any direction.
Hanger attachment devices is capable of carrying either 200 pounds or 3 times the ceiling design load
Members perpendicular to the wall at the unattached sides of the grid shall be tied together with the help of stabilizing bar (stabilized) to prevent their spreading.
Lighting fixtures, egress lighting, speakers, air terminals or mechanical services weighing up to 56 pounds can be supported by suspended ceiling
Sprinkler heads or other similar ceiling penetrations shall be provided with at least 2.54 cm of clearance in all directions surrounding the sprinkler head or extension.
Installation Of Timber Suspended Ceiling:
Grid system is formed with the help of wooden joists.
Modular grid size 400x600mm
Grid system is supported by hanger wire & wooden screws
Each cell is filled with lightweight wooden panels" which simply drop into the grid.
Description of the material
1 Cement Board Indoor
2 Insulation material coat
3 Batten and lath framework 400/600 mm
4 Maxi Screw
7 Joint Filler 14 fire protection plate GKF, 12.5 mm
21 Direct hanger
27 Dividing strips
29 Expansion joint (15-20mm gap)
Polyvinyl chloride (P.V.C.) tiles
Are commonly used floor & suspended ceiling finish
They are small in size , usually 150mm, 225mm and 305mm
The tiles are made of a composite of PVC and fiber
Available in different colors, sizes, designs and patterns
Are used in residences, offices, and commercial areas
The main advantages of PVC tiles are:
Are easy to install & maintenance free
Offer excellent insulation
Are water proof and fire retardant.
Is a panel made of gypsum plaster
It is pressed between two thick sheets of paper.
It is used to make interior walls and ceilings.
The main advantages of gypsum board are:
a) Ease of installation
b) Fire resistance
c) Sound insulation
d) Durability , Economy & Versatility
Is a special kind of board made of sound absorbing materials.
Its job is to provide sound insulation.
Ceiling is porous.
When sound passes through an acoustic board, the intensity of sound is decreased.
The loss of sound energy is balanced by producing heat energy.
Used in auditoriums, halls, seminar rooms, libraries etc
GYPSUM BOARD CEILING
It s a part ceiling with or without covering the primary ceiling. this ceiling is mainly used to play with the levels of the false ceiling to provide lighting.
This system is creatively used, especially at the exhibition galleries and show rooms using very unusual materials like fabrics and other similar materials.
POINTS TO BE NOTED-
Avoid textured or porous materials at the non- air conditioned spaces to avoid accumulation of dust in long run and for better maintenance.
The ceiling material should be selected, in such a way that it can be painted.
The space between the false ceiling and the primary ceiling shall be completely sealed off for better maintenance
Gypboard attached(direct to framing):
Secured directly to framing members or to solid furring.
Most widely used in residential and light commercial
Two layers may be required for an improved fire resistance to sound transmission.
Directly affected by deflection and/or expansion/contraction in supporting framing.
4. PRIMARY AND SECONDARY SUPPORTS:
Primary suspension system may also include a
Secondary system of furring channels used to align
The primary system and/or to provide resilient mounting
of the membrane.
It is a high cost assembly and not widely used.
Resilient furring channels generally used with wood framing
PLASTER OF PARIS FALSE CEILING
WALL TO WALL FALSE CEILING -
It is commonly used. this is a straight forward ceiling with
plane, curve, domed or angular shaped forms connecting all
MATERIALS mostly used in this category are pop,
gypsum board, thermocol, extruded aluminium, ply wood
wooden panneling and ceiling tiles.