Expanded Metal and MIMA
An iconic public sector arts centre which, it is hoped, will transform the cultural landscape of a North East industrial town is the latest landmark building to utilise expanded metal panels in a prominent, architectural role.
Designed by Erick van Egeraat Associated Architects, the £14.2 million Middlesbrough Institute of Modern Art (MIMA) creates for the first time a gallery that brings together the town’s art collection as well as providing space for temporary exhibitions.
Located in the town centre, the structure is surrounded by a £5 million public square that combines with it to create a new cultural and civic heart that could soon rival the famous Transporter Bridge spanning the River Tees as an image by which to identify the place.
The specification of metal mesh sourced from the Expanded Metal Company to provide the underside of the building’s main roof adds to the already impressive credit list for the material which includes the New York Museum of Contemporary Art and the Bilbao Exhibition Centre.
The fact that a UK public building shares a choice of material with such international icons will recommend it to the attention of other architects and designers working in and for the sector. But they will also be able to satisfy the requirements of specifying a material with strong environmental credentials.
Some 500m2 of hot dipped galvanised mild steel mesh was used for the MIMA project. The flat roof extends out over the exterior envelope on the main facade so the expanded metal ceiling for the main atrium is both inside and outside of the building. No special treatment is required for that portion of the ceiling that is exposed to the elements, explains Expanded Metal Company’s Paul Bushnell. ‘It’s precisely the same material on the interior and the exterior and is completely weatherproof.’
The pattern of mesh used was a large one manufactured in panels 2440 mm long by 1220 mm wide which makes for the most economical use of the material. The architects, however, wanted the mesh pattern – created by slitting and stretching the metal – to run widthways rather than lengthways which required retooling at the factory.
A decision on the method of fixing was now needed and, although expanded metal mesh is a lightweight, though robust, product so large a ceiling area required a bespoke treatment. ‘We met with a ceiling contractor from Northumberland, Interceil, explained the project and they came up with a suitable fixing method using a specially constructed Unistrut channel,’ says Paul Bushnell.
Also supplied by Expanded Metal Company for MIMA was cladding for metal boxes sited at the rear of the building as bin stores. These were in aluminium mesh, polyester powder coated in white.
Because Expanded Metal mesh is created by slitting, rather than punching holes, there is a negligible amount of waste material plus the fact that 40 percent of all expanded metal is manufactured directly from recycled material. These factors add considerably to its cost competitiveness.
As the MIMA project illustrates, the production process is versatile enough to meet specific design requirements without difficulty and any ductile material can be used to provide a wide range of thicknesses and patterns and it can be finished in a range of specialist coatings. Although used as cladding or, as in this case, ceiling panels, expanded metal is a structural material which greatly enhances its appeal.
The overall impression created by the use of expanded metal at MIMA is one of functionality reflecting the industrial heritage of an area that had been dependant on heavy industry.
While reflecting this historical flavour aesthetically, however, the specification of expanded metal mesh satisfies the requirements of sustainable 21st century construction.
