Finishing touches

The sense of grandeur that distinguishes the existing museum building has not been overlooked in the new extension. Large, decorative fibrous plaster ceilings in the new conference centre, auditorium and learning centre create highly contemporary, yet equally dynamic public arenas.

The construction of the ceilings was a major part of the contract awarded to South Auckland Fibrous Plasterers. The company was commissioned to provide all the interior linings, gib-stopping and plaster work throughout the new extension.

Director Don Hitchens and project manager Alan Hitchens say the project provided a one-off opportunity to showcase the company's craftsmanship.

"This was a landmark heritage project," they say. "It is rare to get the chance to produce such dramatic, large-scale works. We are particularly appreciative of the architect's vision for the future of the museum."

The piéce de resistance for the project is the large, undulating ceiling of the event centre. Positioned beneath the copper dome, the plaster ceiling is suspended from an internal ceiling, using a USG system. A 4m to 5m gap above the double ceiling accommodates a series of catwalks, providing access to services.

The plaster panels that comprise the ceiling were manufactured by Plastercraft 2000 Ltd a company that owns the original moulds used to create the 80-year-old ceilings in the existing part of the museum.

Director Terry McKain says the company worked from architect drawings to make the new moulds.

"The ceiling resembles the underbelly of a stingray, with the panels designed to create the necessary three-dimensional curves. Some of the panels have up to 10 different radii determining their shape."

Don Hitchens says a lack of space meant laser lines were not able to be used. Consequently, the panels were lined up visually in sections, with moulds created as required.

The ceiling in the learning centre incorporates structural steel beams, which were boxed within L-shaped plaster casts from Plastercraft 2000.

A coffered ceiling was specified for the auditorium in the suspended bowl. South Auckland Fibrous Plasterers designed 1.2m square bays, which are 30cm deep. Light troughs are positioned around the edge of the ceiling, along with a 50mm negative detail that opens to the plenum. This provides an air flow down the walls, eliminating the need for grills and ducting. Plastercraft 2000 Ltd supplied the moulds and U-shaped plaster casts for the ceiling.

As the plant room lies between the auditorium ceiling and the floor of the conference centre, there was a need for extensive acoustic insulation. South Auckland Fibrous Plasterers spent 10 weeks insulating all the steel beams in the plant room before commencing work on the ceilings.

To insulate the auditorium, the ceiling incorporates two layers of 13mm Gib Noiseline and sound clips. The walls of the entire bowl are also extensively insulated. Hitchens says sandwiched between the Fijian kauri exterior and interior lining are two layers of Gib Noiseline, two layers of acoustic Batts, isolation clips within a furring channel, and two further layers of Noiseline. The raked walls within the bowl added to the complexity of the job on all levels.

For more information, contact South Auckland Fibrous Plasterers, 217 St George St, Papatoetoe, Auckland, phone (09) 278 3041, mobile 0274 774 681, fax (09) 277 9695. Email: safpl@hotmail.com.

To contact Plastercraft 2000 Ltd, PO Box 13-300, Onehunga, Auckland, phone (09) 634 8800. Website: www.plastercraft2000.co.nz.

Story by: Trendsideas