1. General:

The following ceiling system is to be supplied and fixed into the areas shown on reflected ceiling drawings, schedule of finishes and/or bill of quantities.

The components specified have been selected on the basis of acoustical, structural and practical grounds and meet the minimum performance and aesthetic requirements of the Architect.

Alternatives submitted in tender will only be accepted upon the prior written approval of the Architects.

Tenders based on alternatives without such prior approval will be deemed as non-conforming.

Material performances are to be supported by Australian Test Data originated from a NATA licensed facility to Australian standards.

2. Ceiling Suspension:

The entire ceiling system is to be suspended by means conforming to the following minimum requirements.

A. Under Concrete Soffits.

i. Primary support will be by means of masonary anchors drilled and expanded into concrete soffits. Each anchor assembly shall be capable of supporting a 200 kg static load without failure. Contractors are to check allowable locations for fixing of anchors with the Structural Engineer and make due allowance for any bridging or bracing necessary to conform to the instructions of the Structural Engineer.

Approved masonary anchors will be fitted with machine punched exposed lower portion of assembly to provide location of hanger rods.

The whole of the anchor and/or bridging and bracing system will be set out to a grid providing for hanger rods to drop plumb over each grid support location.

ii. Hanger rods are to be fixed in single lengths to suit finished ceiling heights. Hangers are to be supported by passing through punched lower segment of masonary anchor and over-bent through 140 degrees to prevent accidental dislodging.

The hanger rod shall be 5mm diameter galvanized steel and will be roll threaded for 75mm of its length at the lower portion, ready to accept heavy duty WF.1 hanger clips with upper and lower adjustment locking nuts as detailed.

B. Under Metal Deck Roofing.

i. Primary support will be taken from metal purlins by means of drilling the web at mid point of the webs dimension. Where purlins do not coincide with necessary hanger locations, provide adequate bridging to accomodate hangers. Should primary support require fixing to bridging or other structural members, the Structural Engineers approval must be sought prior to fixing. No fixing to roof deck will be allowed.

ii. Hanger rods are to be fixed in accordance with the specification items 2 A. i. and ii. noted prior and as detailed.

C. Bridging and Additional Supports.

i. Allow for bridging under mechanical services, structural components and the like.

ii. All bridge and brace designs are to be approved by the Structural Engineer and/or Architects prior to fixing on site.

iii. Ceiling hanger rods either bent or diagonally hung will not be accepted.

iv. Provide additional hangers to main and cross tees where necessary to support special STC rated acoustic tiles, light fittings and the like in accordance with reflected ceiling drawings, schedule of finishes or bill of quantities.

3. Ceiling Support Grid:

The whole of the acoustic ceiling, tiles and light fittings will be supported within a fully exposed modular tee frame- work, set-out to a module of 1200 x 300, 400 and 600 as detailed in the specification hereunder, reflected ceiling drawings and details.

i. Main support tees will be rollformed double web type of .35 galvanized steel base, with .22 pre-painted steel rolled on face cap to selected colour. The main tee will be minimum 38mm high in the vertical leg, having a rectangular formed box section nominally 14mm deep 6mm width at the head which shall be machine punched to accept ceiling hanger clips specified previously. Main tee vertical legs will be machine punched at 100mm centres to accept cross tees where required and shall provide a positive no light, no gap, no twist junction between the two components. The main tee finished face dimension will be 24mm. The main tee will be spaced at 1200mm centres, supported at maximum 1200mm along their length by suspension rods and clips as previously specified. Main tee sections are to be supplied in 3.6m lengths, each having approved machine punched end splices providing a firmly held hair-line joint from main tee to main tee.

Allow to provide additional hangers at main tee joins to be installed at the direction of the Architects. Allow to diagonally brace runs of main tee as necessary to eliminate deviation from straight alignment after installation.

Main tees are to be lapped into perimeter trim and cut short of such trim 50% of the bearing surface of such trim. The main tee will be supported by hangers as previously described within 600mm of any perimeter and shall incorporate a patent main tee to perimeter trim securing clip as detailed and acceptable to the Architects.

ii. Cross tees will be rollformed double web type of .35 galvanized steel base, with .22 pre-painted steel rolled on face caps to selected colour. The cross tee will be minimum 28mm high in the vertical leg, having a circular head profile of around 3mm diameter. The face dimension of the cross tee shall be 24mm to match main tees.

Cross tees will be nominally 1200mm in length and will be spaced at 300/400/600 mm centre to centre to provide the required module size. Each cross tee is to be machine formed at each end to provide an offset overlap and a direct bayonette type positive connection between main and cross tee components, eliminating gap spread, twist or up-lift at such junctions. At intersection of cross tee with perimeters, the cross tees are to be lapped into perimeter trim, cut short by 50% of the bearing surface of such trim and connected to same by patent securing clips as detailed.

Allow adequate diagonal bracing to continuous cross tee runs to eliminate deviation from straight alignment after installation.

iii Perimeter trim will be extruded aluminium angle section sized 30mm x 12mm x 1.2mm thick or galvanized steel angle section sized 18mm x 22mm x 0.6mm complete with adequate fixing lugs to accept main and cross tee intersection clips as specified prior. Aluminium perimeter trim will be painted on visable surfaces to match exposed suspension system in accordance with paint manufacturers direction. The trim is to be fixed securely to perimeter surfaces at 400mm centres by use of fasteners approved for each type of grounds to which the trim is to be fixed.

4. Acoustic Tiles:

Tiles shall be 'Terraton' selected pattern (as supplied by Acoustic & System Sales ... 370 2440) consisting of modular unit sizes as selected and edge profiled as detailed to suit the suspension system as previously specified.

a. Prerequisite:

Ceiling tiles shall be clearly identified within an approved and comprehensive "Product Safety Data" format to Australian Standard.

b. Prohibited Formulation:

Individual tiles shall not rely on any type of applied superficial surface coating, claimed to improve acoustical performance, density or sag resistance. The ceiling tiles must be asbestos free in all respects and evidence of this must be made available in writing by the Manufacturer.

c. Ceiling Tile Construction:

Tiles shall be of wet felted starch bonded mineral fibre construction, containing not less than 82% spun mineral fibres and 1.5% moisture proofing agent dispersed evenly throughout the tile substance.

d. Tile Density and Thickness:

Tiles are to be constructed to a density of 390 kg/m3 and will be face sanded to a uniform 15mm thickness.

e. Acoustical Performance:

NRC shall be in accordance with Australian Standards and fit the range of .72 with an STC of 21 (40-44) Room to Room Method.

f. Airborne Sound Attenuation:

(Two Room Method) AS 2499 - 1981 Ceiling Attenuation Class shall be 43. (CAC 43)

g. Fire Hazard Performance:

The tile must meet early fire hazard performance tests, in accordance with AS 1530 Part 3, 1976 and shall conform to the following minimum requirements.

Flame Spread - Ignitability - Heat Evolved - Smoke Development 0 0 0 2

h. Light Reflectance and Surface Finish:

Paint finish to be vinyl emulsion providing light relectance Grade 1, having a reflectance of 82 - 87%.

i. Stability and Resistance to Sag:

Deflection to be no greater than 1/240th of the tile short side dimension in a controlled environment wherein the relative humidity does not exceed 80% with a maximum temperature of 30 degrees C.

j. Packaging:

Tiles are to be delivered to site in full all round corrugated board cartons. Such cartons must provide full all round protection against moisture entry and protection from reasonable transit and site handling damage.

k. Installation:

Install ceiling tiles into suspension system ensuring directional arrow on rear of tiles point the same direction throughout the installation. Where necessary, neatly cut ceiling tiles to suit part modules or penetrations using a sharp trimmer so as to provide clean edges and minimize production of airborne particles. Ensure that all tiles sit flat in the suspension system and are fully supported on all four sides.

l. Upon Completion:

Check and retify if necessary, all alignments and levels and ensure that the finished ceiling is handed over complete with all components clean, undamaged and defect free.

m. Spare Tiles:

* Upon completion hand over........full size undamaged tiles in unopened cartons. Spare tiles to be identical to those used in the project.

5. Warranty:

Ceiling tiles will be supplied with a manufacturers guarantee as to the abovementioned performance criteria, ability to supply the initial project requirements in the scheduled time and provide replacement tiles when required without delay or unjustified cost penalty.

6. General Requirements:

No part of the ceiling suspension or grid system will be allowed to deflect more that 1/360th of the span of any component utilized.

Ceiling tiles provided and installed will not exceed deflection of 1/240th of the diagonal dimension of such tile. Any tile not conforming to this requirement will be removed from the site and replaced with a conforming tile.