At the leading edge of envelope engineering the members of the Architectural Cladding Association (ACA), are playing a key role in facilitating and resolving client and designer relationships. Martin Clarke, Chief Executive, British Precast explains how.
As the skin between the outside and inside of buildings, precast cladding performs a key role in providing external protection from the elements and securing optimum internal environments for living and working.
The role is growing. Designers have moved away from glass, partly a fashion trend but mainly driven away by the experiences of summer overheating and winter chill. Worries about fire spread between floors have moved interest away from external timber cladding.
The high embodied energy of curtain walling systems is of concern to many specifiers.
Concrete facades are therefore lining up to take a much larger part of the apartment and nonhousing market, and the inherent properties of precast are coming to the fore. A major example is the athletes village being built for the London 2012 Olympics. sustainable design is at the forefront of the ODA programme and precast cladding is being used for the entire village – the largest ever precast cladding project in the UK.
For decades architectural cladding has been the pride of the precast sector, renowned for its high quality. Now the choice of finishes has never been wider. New techniques have incorporated graphics into the concrete itself.
Lighting features and translucence can now be introduced thanks to fibre optics. Glazing is now commonly installed as part of the production process. The latest insulation innovations can be incorporated into sandwich panels. services such as plumbing, electrical circuits and IT cabling are routinely pre-installed in panels. Externally, solar gain can be minimised by the incorporation of brise soleil, shutters and shading features.
Internally, comfort and health can be improved by exploiting the thermal mass of concrete and the managed purging of stale air.
Although the ACA encourages a holistic life-cycle approach to the design of sustainable buildings, its members are addressing the challenge of improving the sustainability profileof architectural cladding. This is being achieved in a number of ways within the British Precast Concrete Federation of which the ACA is a key member association.
Firstly on health and safety our Concrete Targets 2015 programme which has been adopted by all Federation members aspires to move the precast industry to being a zero harm sector both within the production plant and during the installation phase. Excellent progress has been made over the last 10 years but there remains some way to go to reach our target.
In May 2011 all members of British Precast will be required to sign up to the Federation’s sustainability Charter. We will become the first construction trade body to take such a stance – all part of our Raising the Bar initiative aimed at improving all aspects of the industry.
The drive to reduce embodied and operational carbon is fully integrated into our programmes and progress is reported annually with the publication of our key performance indicators.
For further details visit: www.britishprecast.org
Decomo helps write the next chapter for the Bodleian Library
Having opened back in 1602 and now with more than 11 million books already on its shelves, the Bodleian Library at Oxford University had been fast running out of space for many years. What’s more, as it receives a copy of every published work in Britain, this means finding a home for some 1000 new books every day, equivalent to three miles of shelving a year.
Known as the Bodleian Book Storage Facility at South Marston, Swindon, that new home – capable of holding 8.4 million volumes on 153 miles of shelving – is now complete.
The new book warehouse will store lower-usage items from the libraries’ collections that had overwhelmed the existing bookstacks and required additional temporary storage in various locations in and outside Oxford. These collections will now be brought together at the BSF, including books, maps, manuscripts, microfilms, periodicals and newspapers primarily from the 18th century onwards. Over the next year, nearly six million books will be moved into the BSF in what will be the biggest book move in the Bodleian’s history.
Decomo UK Ltd worked with main contractors Mace Plus and architects Scott Brownrigg to deliver this new large storage facility. Precast concrete sandwich panels were the chosen material for the facades, allowing fast erection on site and providing a durable finished surface both inside and out.
An added challenge to Decomo’s package of works for the design, manufacture and installation, was that the walls needed to provide a minimum of four hours’ fire protection to safeguard the valuable contents from any external fire. Because of their twin layers, concrete sandwich panels already offer good levels of fire protection but careful consideration was needed in the design of the individual concrete layer section thicknesses, and the panel-topanel jointing system adopted, in order to meet the stringent requirement.
Architectural grade precast panels were supplied with a grit-blasted finish to the external faces. Typical dimensions were 7.5m long × 3m high, each weighing 12.5 tonnes each: some were larger, the biggest closer to 18.5 tonnes. Panels to the front elevation – which houses the reception and offices – had the added feature of a relief pattern, simulating the appearance of books stored on bookshelves.
Decomo was able to accommodate the short lead-in period for this project. Design began in August 2009, with all 254 cladding panels (totalling 5200m2) manufactured by Decomo and erected on site starting in January 2010. The installation was completed in just eight weeks, despite some of the heaviest snowfalls seen in decades in this country. All facade panels were installed using a 70-tonne crawler crane, except for the area above the reception/ office block, where a 200-tonne mobile crane had to be used.
Once the building was watertight, work could begin by the following trades to install the 2200 linear metres of 11m-high raking that provides 95,000 shelf levels. Work has already begun on transferring the millions of books from the original Bodleian and other temporary storage areas to the new facility in Swindon.