DESCRIPTION

Composition

The tiles are manufactured from GRG (glass reinforced gypsum) and comprise non-combustible gypsum casting plaster reinforced with a glassfibre membrane resulting in a lightweight, strong, naturally prestressed panel.

Surface finish

The plaster has a moulded fine, smooth or textured finish and may be supplied pre-decorated to order or with a natural finish.

Dimensional tolerance

plus or minus 0.5mm.

Specials

Sizes:

Tiles of special module sizes from 300x300 to 1500x1500 can be produced to order if not available as a standard product.

Designs:

The designer's imagination is the only limit to what may be produced in terms of shape, pattern and surface finish, and this applies not only to ceiling tiles but other architectural products such as column casings etc. where products can be up to 4m².

Performance:

High performance tiles can be designed for the most demanding applications where special environmental requirements are called for.

PERFORMANCE

Fire Performance

British Standards:

Non-combustibility:

GSP tiles are rated non-combustible as defined in BS 476 : Part 4:1970 (SGS Yarsley Technical Services, 16-9-92).

Surface spread of flame:

GSP tiles are rated Class 1 for surface spread of flame to BS 476: Part 7: 1987 (SGS Yarsley Technical Services, 19-8-92).

Fire propagation:

Tested to BS 476 : Part 6: 1989, GSP tiles achieved a final index of 1.4 indicating a Class 0 material in accordance with Appendix A, Clause A12 of the Approved Document B to the Building Regulations 1991(SGS Yarsley Technical Services, 19-8-92).

Smoke and toxic fume emission:

GSP tiles are zero rated for smoke emission (Warrington Research Centre, 3-3-80). No toxic fumes are given off.

American Standards:

Flame Spread and Smoke Density:

Tested in accordance with ASTM Designation E84-97a, "Standard Method of Test for Surface Burning Characteristics of Building Materials", GSP tiles achieved a flame spread and smoke density value of 0 (nil) equalling NFPA Class A and UBC Class 1 (SGS U.S. Testing Company Inc., 15-6-98).

Combustion Characteristics:

GSP tiles meet the requirements of ASTM Designation E136-95, "Behaviour of Materials in a Vertical Tube Furnace at 750°C (1382°F)" (SGS U.S. Testing Company Inc., 15-6-98).

Humidity

The tiles have excellent moisture resistance and can be used in areas of high humidity including covered external areas. Tested in an atmosphere of 95% RH at 21 deg C for 14 days, the tiles did not sag or distort and showed only minimal increase in weight (Harry Stanger report 11-7-84).

Acoustics

Sound absorption:

High performance perforated plaster tiles are able to achieve Noise Reduction Coefficients (NRC) of 0.74 (equal to perforated metal tiles), while semi-perforated tiles e.g. A706, have NRC values of 0.58 (equal to mineral fibre tiles).

Sound attenuation:

Tests have confirmed Sound Transmission Coefficients (STC) of 38 using T206 tiles and proper partition head seals. Similar results can be expected for all tiles except Rockwool backed open cell tiles where the value falls off slightly to about 35.

Point loading

Each tile will accept a point load of up to 13kg without the need of a yoke.

Biological

GSP tiles will not support the growth of bacteria or other micro organisms.

Thermal

Thermal conductivity, (k value): 0.45W/mK

Optical

Light reflectance of self-finished tiles is estimated at 75%.

Life-span

Under normal conditions GSP tiles will not deteriorate and can be expected to last the lifetime of the building.

SITEWORK

Transport, handling and storage

Tiles are supplied shrink-wrapped or packed in cardboard cartons. Tile cartons should be stacked in the vertical position only, never flat; the stack should be a maximum of 3 high. Similarly, tiles should be stacked vertically when awaiting fixing. The exception to this rule is the Economy tile which has been designed to be stored and transported flat.

Installation

With a few exceptions, the tiles are designed for installation on a standard 25mm table exposed metal grid; including concealed tiles.

Grid Hanging centres depend on the weight of tiles used and will be specified by the grid manufacturer; the recommended dimensions should be strictly followed.

Cutting

Tiles can be easily cut on site using a carpenters fine tooth saw; the tiles should be placed face up on a flat, clean surface for cutting.

Light fittings

Particular care should be exercised in selecting light fittings for use with suspended ceilings; certain types and classes of fitting may be found to create undesirable lighting effects.

The most satisfactory and functional fitting is the flush, recessed luminaire; this will be found to provide excellent general illumination while eliminating shadow effects on the ceiling caused by side lighting.

Light sources and fixtures which cause grazing lighting effects across the ceiling surface are not generally satisfactory. These fittings may result in exaggeration of surface irregularities as small as 0.1mm (particularly on fine textured tiles) and may also create apparent colour variations in the tiles.

Decoration

Where unpainted tiles are supplied and special finishes are required, the most effective method of painting is to dip the tiles in a tank containing a dilute solution of emulsion paint. Depending on the type of paint, 1 part paint : 4 parts water usually works, but a little experimentation may be needed. Dip time will range from 5 - 30 seconds depending on density of colour, agitation of the tile is required to release entrapped air bubbles. The painted tiles can be installed in the grid within 5 minutes and left to dry in situ.

The tiles can also be decorated in situ to individual requirements using emulsion, acrylic or oil-based paints in gloss, matt or eggshell finishes applied by brush or spray.

Access

Lay-in tiles are easily removed at any time by simply lifting them out, thus providing excellent access to services etc. installed in the ceiling void. Concealed tiles are also easily de-mounted although the method used will vary depending on the particular tile used.

Maintenance

GSP tiles can be cleaned with a slightly damp cloth or even washed in a bath using a mild detergent solution.