Report on Suspended Ceiling

What is Suspended ceiling?A suspended ceiling is a secondary ceiling, hung below the main (structural) ceiling. They may also be referred to as adrop ceiling,false ceiling, or dropped ceiling, and are a staple of modernconstruction and architecture.

The area above the dropped ceiling is called theplenum space, as it is sometimes used forHVACair return. The plenum space is also very commonly used to concealpiping,wiring, and/orductwork.

A typical dropped ceiling consists of a grid-work of metal channels in the shape of an upside-down "T", suspended on wires from the overhead structure. These channels snap together in a regularly spaced pattern - typically a 2x2 foot square grid or 2x4 foot rectangular grid, or 600 x 600mm grid.

Each cell is filled with lightweight "tiles" or "panels" which simply drop into the grid.

Tiles can be selected with a variety of materials, including wood, metal, plastic, or mineral fibres, and can come in almost any colour.

Components of Suspended CeilingThere are five key parts of a suspended ceiling system-

Main runners, the primary support members, are arranged in parallel rows that run the length of the room. Main runners come in a variety of finishes and shapes.

Cross runners are lighter-gauge supports that fit between the main runners at right angles.

Hangers are lengths of lightweight (usually 18-gauge) wire. One end of each hanger hooks into holes in the main runners, while the other end attaches to the ceiling joists.

Ceiling panels fit into the grid created by the runners. The panels can be square or rectangular and come in a variety of sizes and patterns.

Wall moulding is a metal channel attached to the walls. The moulding supports ceiling panels around the perimeter of the room.

Types of Suspended CeilingEXPOSED GRID Exposed grid varieties are the most common type of suspended ceiling. They consist of long metal strips, called "mains," which are interconnected with shorter metal pieces known as "tees." Together, the mains and tees form a grid system of 2' by 2' or 2' by 4' squares, which are then filled with acoustical ceiling tiles. These exposed grid systems feature a standard 15/16" wide metal frame around each tile, though wider and narrower versions are also available.

CONCEALED GRID

Concealed grid systems use the acoustical tiles to hide the grid system from view. This creates a smooth, clean look that many find to be aesthetically pleasing. The tile used in a concealed system has a small groove built into it's perimeter, which slides over the mains and tees to cover them. This type of system is more expensive than an exposed system, and can make it difficult for maintenance personnel to access areas above the ceiling.

Types of Suspended CeilingBANDRASTER

Bandraster systems are one of the most versatile types of suspended ceilings. They are comprised of metal tees and mains of varying lengths, which can be used to form a variety of patterns. These systems are often used by building owners who want to create a certain look with their ceiling, as they can be arranged in many different ways. Bandraster ceilings require the use of specially-sized tile to fit within the unique grid patterns.

SUSPENDED DRYWALL CEILINGSSome suspended ceiling systems do not require the use of metal grid, and instead use wires and hangers to suspend sheets of drywall below the ceiling. These systems are an easier alternative to the extensive framing and hat channel that are typically required to create drywall arches or ceiling structures. Flat sheets of suspended drywall or panels may also be hung below ceiling level to provide acoustical or aesthetic benefits .

Uses of Suspended CeilingThey are used to cover up air ducts and maintenance areas of Light fixtures HVAC airgrilles Speakers Fire sprinkler2. The suspended ceiling was originally developed to conceal the underside of the floor above and to offer acoustic balance and control in a room. Dropped ceiling, after installation. Light fixtures, a speaker grill, smoke detectors, and an air grill are all visible.Interlocked panels can be "slid" across and out of the grid

Advantages Very good for fire safety, you can get ceiling tiles that are made from certain mineral fibres or fire proof fibres that will meet fire codes around the world and possibly save you or others lives.

Another advantage of a dropped ceiling is that the easily-removed ceiling panels offer instant access to the plenum, greatly simplifying repairs or alterations.The tiles and other parts of a drop ceiling are easily removed to allow access to the area above the grid to do any necessary wiring or plumbing modifications.

Nearly all components the grid can be dismantled and reassembled somewhere else.

Gives thermal insulation.

As a design element. Numerous colours and patterns thus making the space look good.

To soundproof rooms such as meeting rooms, auditoriums, etc, which require a quit environment.

Disadvantages One disadvantage with this ceiling system is reduced headroom. Clearance is required between the grid and any pipes or ductwork above to install the ceiling tiles and light fixtures. In general, a minimum clearance of four to eight inches is often needed between the lowest obstruction and the level of the ceiling grid.

Dropped ceilings are frequently used byslumlord to hide structural and cosmetic damage, loose wiring, insect/rodent infestation, avoiding the need to carry out any repairs or maintenance.

They tend to show their age quickly (and are sometimes discoloured by excessive smoking), are damaged easily and are somewhat lacking aesthetically.

The space between the true ceiling and the suspended ceiling gets very dusty over a period of time.

MaterialsGYPSUM BOARD (GYPBOARD)

Lightweight, flexible and fire and moisture resistant, gypsum is most commonly used for false ceiling. Gypsum board panels are tough, versatile and economical, and are fast replacing other ceiling materials such as POP. Gypsum board can be used while constructing false ceiling. as well as to renovate old ceilings. The material is fire-resistant, waterproof, as well as soundproof, which is why it is the most preferred material for false ceiling. A gypsum panel could have tapered or square edges. Panels with tapered adage are used for ceiling since the gap between each edge can be filled, to give a smooth surface. Square-edges board can be used. Where visibility of the joints is a requirement. A suspended Gypsum board ceiling can be constructed by nailing Gypsum board panels to each other, or by fixing the panels in a metal grid (usually steel). Generally, gypsum panels of 600 mm600mm are used.

MaterialsGYPSUM CEILING ARE POPULAR BECAUSE:

The dry construction eliminates the use of extra water while making the ceiling. This also keeps the building clean. Gypsum board is quite flexible. It allows for various shapes and design-such as plain, curved, stepped, coffered, pelmet, drop design, etc. Gypsum board has high impact-resistance and is very strong. It is possible to suspend a load of up to 15 kg from the ceiling without any difficulty. A Gyp board ceiling suspended on a metal grid forms a strong ceiling design. The ceiling can be easily decorated with wallpaper or paint, 24 hours after it is constructed. Glass fibre-reinforced gyp board makes excellent insulation material. Gypsum ceilings are non-resonant which makes then good soundproofing. When exposed to fire, gypsum gives out water, which is converted to steam and helps combat the fire. This is what makes the ceiling fireproof.

Details : gypsum board fixing

Details : gypsum board fixing

Details : Clip in Ceiling System

Details : Lay in Ceiling System

Details : Furring Ceiling System

Materials2. METAL CEILING PANELS

Metals ceilings are suitable for a large Range of applications. The false ceiling is constructed with metal panels. Which are coupled with insulating materials to make them soundproof. They are ideal for concealing ducts and wiring, since they can be easily installed and maintained. Aluminium or steel panels, 600mm600mm in size, are generally used. The panels can be laid on a visible steel grid with T-sections or cross-sections that are suspended from the ceiling by rods. This result is strong, long-lasting surface, which is easy to access. The panels can also be clipped to each other or clipping into a suspension system having springs. That method prevents the panel edges from being seen. The third method is to stretch the metal sheets to form various shapes, which can be suspended form the ceiling. This treatment is ideal for obtaining a variety of shapes in the metal, without changing its soundproofing ability.

MaterialsADVANTAGES OF METAL CEILING:

They reduce overall cost, since they are easy to install and access. Hidden services can be easily accessed since the panels are removable. They are ideal for workspaces which require clean environments and services that require maintenance such as the machinery rooms, the AHU, etc. They have a monolithic look. They give the space a very modern look and blend well with glass.

MaterialsFIBREBOARED AND FIBRE/MINRAL REINFORCED TILES

False ceiling can be made with fibre or mineral reinforced tiles and fibreboard. Fibre reinforced tiles are strengthened with wood vegetable fibre, wood waste, reed paper and agricultural wastes. Mineral tiles are Ceramics reinforced with natural stone, wood, vegetable fibre, bitumen and tars. This process increases the insulation capacity of the product.

FIBREMINERAL-REINFORCED MATERIALS ARE USED BECAUSE: They have high insulation against sound and fire. The fibre increases the hardness and the toughness of the material. The material can be decorated with paint or other finishes improving the aesthetics of the room. Water repellents and preservatives can be added to increase the life of the product.

MaterialsPLASTER OF PARIS

Plaster of Paris (POP) is commonly used for constructing false ceilings. Gypsum, which gives out water when heated, makes POP. Post-heating, gypsum softens and is then crushed to form a powder. POP hardens instantly when water is added to it. It is applied to fibreboard or a wood base, which is then suspended to form the false ceiling.

ADVANTAGES OF POP

A smooth, uniform finish. The surface can be recorded or painted. POP false ceiling are easy to construct and maintain. The ceilings are reality light.

MaterialsPLYWOOD

Plywood ceiling are widely used for their visual appeal. These ceilings are created with strips of ply glued or nailed together. The strips are held together and strengthened with ply supports at equal distances. Ply ceiling are generally used in place with cold climates.

ADVANTAGE OF PLY CEILINGS They are strong and look appealing. They can be given various finishes, or painted to get the right look. They can be treated to increase their lifespan.

However, ply ceiling are difficult to maintain, since the are prone to termite attacks. The room has to be thermally controlled to reduce the humidity in the air. Also, the wood is prone to warping and other physical changes, with time.

Safety issues The space above the dropped ceiling is often used as aplenumair return for ventilation systems, requiring only enclosed ducts that deliver fresh air into the room below. Return air enters the ceiling space through open grilles across the ceiling. In the event that the dropped ceiling is used as a plenum, low-voltage cables and wiring not installed inside conduit need to use a special low-smoke and low-toxicity wire insulation which will tend to char and stop burning on its own. This helps to protect building occupants so that they are not poisoned with toxic chemicals sucked through the ventilation system in the event of a fire, and helps to prevent fires from spreading inside the hidden plenum space. This special low-smoke cable is typically referred to asplenum cable.

Lighting fixtures and other devices installed in a dropped ceiling are required to be firmly secured to the dropped ceiling framework. Binding the fixtures to the framework assures that if the framework must be pulled down the fixture will come down with it and not become a pendulous swinging hazard to the firemen.

How to install ?PLAN THE JOB Make a plan-view drawing to determine the number of cross runners and ceiling panels you'll need, as well as the lineal feet of the main runners. Panels are available of different sizes e.g. 24x24-inch and 24x48-inch sizes. The latter works better if you'll use fluorescent lighting; the panels fit the standard fluorescent tube length. Smaller panels require more cross runners, so the job is more time-consuming. Wall moulding and main runners are sold in different lengths.

2) LOCATE THE BENCHMARKS

The key to success is making sure marking the ceiling level across the entire room. Existing floor and ceiling surfaces may not be level, so never use them as reference points for measuring. Instead, establish benchmarks on the walls at every corner using a water level to ensure that each benchmark is precisely located. Benchmarks can be placed at any height, but a 60-inch height is most convenient. Future measurements will be taken from these benchmarks.

How to install ?3) DETERMINE THE CEILING HEIGHT The standard ceiling height is 96 inches; 90 inches is the minimum height for lighting in a suspended ceiling. Once the ceiling height is determined, measure up from the benchmarks to locate the top edge of the wall moulding. Snap a chalk line between the new marks on the walls around the perimeter of theroom.

4) INSTALL THE WALL MOULDING

Using the chalk lines as a placement guide for the top edge of the moulding, nail moulding to the walls using nails. Make sure each nail penetrates a stud. When cutting the wall moulding to length, remember to account for the thickness of the adjacent wall angle. Butt lengths of wall moulding where they meet mid-wall.

How to install ?5) ESTABLISH THE CENTERLINES

Measure the length and width of the room and divide these measurements in half to get the centre point of each wall. Use layout strings, stretching them tightly, to connect opposing midpoints. With a framing square, check the intersection of the two strings to make sure they're square to each other. If not, adjust one or the other until they are. It's easier to adjust layout strings when they're attached to nails that can be wedged behind wall moulding.

6) ADJUST THE LAYOUT

Plan the layout of ceiling panels to minimize the need for small pieces around the border of the ceiling; this will create a better-looking job. If the border tiles will be less than half the width of a field tile, adjust the layout one way or the other until the border panels on opposite sides of the ceiling are the same size.

How to install ?7) INSTALL THE GUIDELINES

Plan to install the first main runner approximately parallel to the wall and at a distance from the wall equal to the width of the border units. Measure from the centrelines rather than from the wall, since the wall might not be square. Stretch a layout string between the lower edges of the wall mouldings at these points.

8) ATTACH THE HANGER WIRES

Start with the joists at either end of the ceiling. Install a screw eye or a fastener supplied by the ceiling manufacturer into every fourth joist directly above the layout string. Twist a piece of hanger wire through each screw eye so that it hangs about 6 inches below the layout line. Cut a main runner to length and hang it from the wires so that it's just barely above the layout string. Twist the wires to secure the runner in position.

How to install ?9) INSTALL THE CROSS RUNNERS

Slip the first cross runner between the main runner and the wall moulding, locking it into the main runner's prepunched slots. Install the next main runner by using cross runners to gauge its spacing; maintain the proper spacing according to the size of the ceiling panels being used. Continue to work across the room until all the runners have been installed.

10) INSERT THE CEILING PANELS

Set each ceiling panel into place by turning it at an angle and pushing it into the grid of runners. Use a utility knife and a straightedge to cut the panels at the borders as needed. When handling the panels, one should wear clean, lightweight gloves so one don't smudge the finished surfaces.