Interpon | The Shard, UK

The Shard, UK

Interpon D2000 Series: The Perfect Choice for Europe’s Tallest Building

A visitor to London on 5th July 2012 would have seen lasers lighting up the night sky, bouncing off St Paul’s Cathedral and reflecting off the surface off the Thames.  Tracing them back to their source, the visitor would find they emanated from a grand new structure on the south bank of the river at London Bridge.  It was the grand opening of the building that has become known as the Shard, due to its resemblance to a giant shard of glass.  Standing at 310m high, it is currently the tallest building in western Europe.

The origins of the project go back to 2000, when the UK government drew up new guidelines to encourage the construction of high-density buildings at transport nodes.  Renzo Piano (most famous for his collaboration with Richard Rogers on Paris’ Pompidou Centre) was approached to design an iconic building next to London Bridge station.  The mainline and underground train stations see over 50 million passengers per year passing through.  Placing a high density building on the doorstep was envisaged as a great way to cut commuting times whilst giving people a pleasant and inspiring place to work or live, as well as the chance to stay at the building’s landmark hotel.  High-density does not have to mean high-rise, but in this case the site was perfect for a tall building.

Eschewing the use of colour, Piano designed a building where the predominant element is glass.  The supporting façade elements use neutral white and grey materials so as to allow the reflection of the sky to be the main visual impact.  Naturally given the modern focus on sustainability the project needed also to demonstrate how it could achieve a low environmental impact.  Piano’s use of glass does this in two ways – firstly the use of a double skin (a single glazed exterior and double glazed interior skin, with blinds sandwiched between), and secondly by allowing light to penetrate deep into the floor areas, minimising the need for artificial light.

The building has been criticised by English Heritage (a UK conservation organisation) amongst others, and was the subject of a planning appeal where the government ultimately overrode the local authorities and gave the go-ahead, seeing the development as being of an outstanding design.  Piano himself likens its form to the city’s many spires, but in a modern styling.

Sustainability also dictated other elements, notably the installation of a combined heat-and-power generating plant, and the choice of coating.  For the exterior, Piano wanted unobtrusive shades in a sustainable system with colour uniformity over a large surface area.  This led to the choice of polyester powder coating (PPC), which contains no solvent and is factory applied, meaning colour on all parts can be checked against a master before shipping to site.

Typically in the UK, when specifying PPC the obsolescent standard BS6496, or its successor BS EN 12206, are quoted.  These specifications mean that the coating need achieve only 12 months of weathering in south Florida (retaining 50% of its original gloss level).  Standard PPC systems based on terepthallic acid can achieve the 12 month test, but generally by the end of 2 years they have lost all gloss as the surface has degraded.  This would of course take many more years in the UK, but if a building is expected to look good over a longer period and not require repainting, it makes sense to specify a higher durability system, and increasingly this is happening in London and elsewhere.

Available already for more than 21 years, PPCs based on isopthallic acid can meet a much tougher 5-year test in Florida and are consequently referred to as super-durable powder coatings.  Take-up has been slow for a couple of reasons.  One is cost: being in low demand or specified in project specific colours, superdurable polyesters are made in small quantities, while standard PPC coatings are made cheaply in bulk and held in stock.  The other is inertia because specifiers are used to standard PPC systems and they have a good reputation for durability.  As the older buildings age however, the drawbacks are being seen in faded colour and premature loss of gloss.

The curtain wall contractor for the Shard was Scheldebouw, part of the Permasteelisa group.  Renowned for the envelopes on many of the world’s most innovative shaped buildings including the Sydney Opera House and Bilbao’s Guggenheim Museum, they regularly recommend their clients to use superdurable powder coatings.  This was true on the Shard, where the system with the longest track record, AkzoNobel Powder Coating’s Interpon D2000 system, was selected.  This product was first used on a hospital in California in 1991, and measurements earlier in 2012 showed that 21 years later it still has more than 50% of its original gloss.  In London’s cooler climate it should be expected to keep the Shard looking good well into the future.

For the interior there was a second area requiring sustainable solutions and colour consistency – the ceilings.  From floor 2 to 28 the Shard contains offices.  Concealing the ventilation and cabling, and holding the sprinkler systems, is best done with a suspended ceiling, and the most durable solution is to use  metal ceiling tiles coated with a fire-resistant powder coating.  The ceiling needs to be unobtrusive but also to help project daylight deep into the building.   In this case a brilliant white fine-textured PPC was used, this time from AkzoNobel’s Interpon D1000 series.  This is a standard (terepthallic acid) PPC system, which is a perfect choice given the lower UV levels behind glass.  The ceiling contractor, SAS International, has wide experience on landmark projects including Santiago airport in Spain and the lauded 1 Bligh Street development in Sydney which set new standards in sustainability.

From the outside Londoners and visitors alike can already appreciate the visual impact of The Shard on the skyline.  It is only when it opens to the public in 2013 that they can appreciate the light, airy atmosphere created by the combination of glass, shape and use of light colours.  Thanks to the choice of superior coatings, visitors in 2037 and beyond should get the same experience.

 

The following 1 Powder Coating series is/are suitable for Architecture

Interpon D2000

These coatings are specially designed for the architectural and construction industry, and have been proven over a 20 year lifespan. They are mainly used on aluminium and galvanised steel, but can be used anywhere that attractive, durable colors are required.