CMS Danskin: Putting the ‘Shhh’ in the Shard
Distinctive, unconventional and controversial, the Shard is, undoubtedly, the work of a visionary. Rentzo Piano, the architect behind the Shard, currently the tallest building in the European Union, is no stranger to controversy, having designed buildings like the Pompidou Centre in Paris, with its exposed pipes, ducts and cabling. It’s unsurprising that Piano has an expanding collection of architectural awards, including the Royal Gold Prize, the AIA Gold Medal, and the Pritzker Architectural Prize, as well as the Sonning Prize, recognising his broader contribution to Europe’s cultural life. But for every architectural visionary there are whole armies of technicians and tradespeople striving to turn the architect’s vision into a practical reality.
When CMS Danskin Acoustics Limited was engaged by Progressive Group to ensure the Shangri-La Hotel’s 42 floors in the Shard were effectively soundproofed, it wasn’t a straightforward assignment. From the very first sketches drawn on a napkin by Piano during dinner with entrepreneur and property developer Irvine Sellar, the Shard was always intended to be ‘all about the windows’, with expressive façades of angled glass reflecting sunlight and the sky, and affording 360° views of the city.
Unfortunately, when the glazing is central to the design, floors can get in the way of the overall effect, and the temptation is to minimise floor heights (within Building Regulation parameters, of course). This presents a significant challenge to acoustic insulation installers. In short, the thinner the floor, the harder the soundproofing material has to work acoustically and the more physical punishment it has to endure.
For approximately 70% of the floors, Progressive applied a Gyvlon liquid screed at a 40mm minimum thickness. The screed was pumped from ground level, with the largest pour in excess of 80m3 covering an area of 1,680m2. In approximately 30% of the floor areas, however, the floor screeding level could not be raised because of the existing floor-level transom in the curtain walling. This meant that there were instances of screed thicknesses of approximately 25mm in places.
CMS Danskin’s Regupol E48 was specified, a Robust Detail approved (E-FC-6) high-performance screed isolation material. E48 was perfect for those ‘thin screed’ areas, with its maximum load bearing capacity of 3000kg/m3 (30kN/m2), combined with a mean average impact sound insulation performance of 46dB and a mean average airborne sound insulation performance of 49dB, both values well in excess of the requirements of Part E of the Building Regulations.
Building Regulations aside, E48’s ‘over-performance’ is crucial for a hotel as exclusive as the Shangri-La. The award-winning, globe-spanning hotel group prides itself on providing a customer-focused experience, with the emphasis very much on luxury. Intrusive noise from above or below a guest’s accommodation would almost certainly undermine those efforts. Plus, with this being a flagship project for the Shangri-La – their first hotel in Europe – ‘fit for purpose’ simply wasn’t an option.
As a Robust Detail underscreed, E48 has already been rigorously pre-tested to ensure it achieves a minimum performance of 5dB over and above Part E, thus eliminating the need for Pre-Completion Testing. However, CMS Danskin and Progressive, having worked together successfully on the exclusive One Hyde Park development, preferred to adopt a partnership approach, with the emphasis on planning and testing, giving absolute certainty to all parties and making full use of all the skills, expertise and experience at their disposal. To this end, Paul Absolon, CMS Danskin’s Technical Director, worked closely with Progressive’s technicians, carrying out off-site simulations and fitting trials with varying screed thicknesses. Only once both parties were satisfied with every aspect of E48’s acoustic performance in a ‘real world’ situation did the installation proceed.
More than 16,000m2 of E48 were installed over approximately 3 months, with Progressive and CMS Danskin maintaining their close working relationship throughout.
Tony Cooney, Estimating Manager at Progressive Group, said, “The completion of the screed and insulation work on the Shangri La Hotel development was a fantastic achievement and it presented a number of very challenging situations – both technical and logistical. Solutions to these challenging situations are achieved by the co-operation of all parties involved – including material suppliers. The technical assistance provided by CMS Danskin on this Shangri-La project and other prestigious contracts in the London region in recent years has been exceptional and we look forward to continuing our excellent relationship.”
Said Paul Absolon, “It was a privilege working on a project as ground-breaking and culturally significant as The Shard, and it was a pleasure working with the professionals at Progressive Group again. At CMS Danskin, we like to be put to the test. The Shard certainly was a challenge and we’re proud to have met that challenge and delivered.”