'Acoustics' standard detail sheet # 6 shows a good general assembly of the two ceilings, one fitted above the other.

The first ceiling, comprising 13mm thick gyprock panels fitted into a 1200 x 600 exposed grid system, is designed to act as an acoustical barrier to sound passing from one area to another. It is very important that the gyprock panels are bedded into a mastic or closed cell foam tape material on all the supporting surfaces (tee bars and angles) so to avoid sound transfer through air spaces which would otherwise be evident in the panel system. Use 25 x 25 x 0.8mm galvanised angle sections at the perimeters of this ceiling. Use the same 25 x 25 galv angle material for hangers to the main tee section at points not exceeding 1200mm along it's length.

As this ceiling is not seen in the finished work, it's not important to set it out to normal architectural symetrical requirements. It should be remembered however that the 'metal strip ceiling' is to be supported from the main tees of the panel ceiling and therefore such main tees will need to be put into locations suitable for that purpose. It is desirable to set-out the metal strip ceiling carrier rail locations below the panel ceiling grid work and to install the 4g16 twist clip hanger part to the exposed main tee, before installing and sealing in the gyprock panels. This allows you to correctly seal the panel ceiling without the need to break that seal if putting in the 4g16 clips afterwards.

The second ceiling comprises the standard perforated 'paneline' metal strip ceiling system, complete with black faced insulation over, fitted directly below the gyprock panel ceiling by means of the composite 4g16/4ac clip hanger assemblies. Use the m.3600 prefinished wall angles at the perimeter of the visable metal strip ceiling system.

Notes:

I/ ensure that all penetrations through the gypock panel ceiling for electrical cabling and the like are properly sealed up before completing the metal strip ceiling.

Ii/ if this ceiling is being installed in conjunction with a 'won-door' acoustical folding partition or 'huppe' operable wall, ensure that an acoustical bulkhead/wall assembly is installed in the space between the top of the metal strip ceiling and underside of gyprock panel ceiling. To achieve the very best room to room isolation, continue the acoustical bulkhead through the gyprock panel ceiling to the underside of the roof or soffit over.