Inner city workling - Cantillon at Davies Street

In 2012, Cantillon Limited was appointed by Sir Robert McAlpine to deconstruct rather than demolish 29-37 Davies Street, Mayfair, London, a 7 storey building (including the basement) because of several environmental issues that needed to be considered - out-loading material arisings from the deconstruction, noise from the work, the inevitable dust that would be created from a building some 100 years old, asbestos containing materials (ACM) and not least of all being able to manage a project of this size in one of the most congested areas in West London without causing a nuisance that would increase what is already a very real traffic problem. The location of the building required careful thought about how out-loading materials would be carried out, as can be seen from the location; directly behind the building were the Italian and Canadian Embassies and the Argentine Consulate, Grosvenor Sq. Garden to the west, New Bond Street and Hanover Sq. just to the east and Grosvenor Street to the south. To the north end of Davies Street was a Crossrail Project Site that had to be brought into the project planning. It was crucial therefore that disruption to residents and local businesses was absolutely minimised – from start to finish.

The materials from which the structure was built were nothing out of the ordinary; brick, steel, concrete, glass, wood and other metals etc. However, what made this building a little more thought provoking was that several floors had much of their walls and ceilings painted in a bitumen paint that contained asbestos, acting as a fire retardant product. The problem lay in removing the ACM (which was deemed as non-licensable work) without allowing it become friable and therefore detrimental to the public who passed by the building (a major thoroughfare to Oxford Street to the north), of course to the wider environment itself, to contaminate other arisings from the deconstruction, that might be used on other construction sites after processing, and not least of all to operatives working on the project.

Cantillon utilises a range of innovative measures to significantly improve the control it has over noise production during work. With noise likely to be the main complaint area the company had to ensure that it was reduced as much as possible. To establish the likely problem areas Cantillon created several 3D noise models predicting noise levels from the ground to 5th floor, showing at each height what the predicted levels were likely to be for the surrounding buildings.

This was completed before commencing work and buildings particularly susceptible to noise were identified. Reducing noise by engineering methods always comes second to eliminating noise through methodology; however in this instance Cantillon was unable to eliminate it all together. With knowing the buildings where noise was likely to be a problem; 29-37 Davies Street was encapsulated and instead of using just using fire retardant sheeting, Powerclad Acoustic sheeting (also fire retardant) was used and in places acoustic blankets were positioned to enhance attenuation further.

Removing the ACM was now the next issue to overcome. This had to done with the least amount of problems both to the public and wider environment and was achieved by treating it as Licensable Asbestos and enclosing all the areas where it had to be removed. This ensured that nothing would escape. Next Cantillon wanted to remove it using something that was as environmentally friendly as possible and research identified a substance that was derived from citrus fruit, thus replacing substances such as chlorinated and kerosene based solvents.

The substance softened the bitumen allowing it to be scraped off the surfaces but also keeping any asbestos fibres within the confines of the bitumen;. This allowed the arisings to be easily packaged and sent away for disposal, eliminating environmental and indeed personal contamination. Although not possible in this case because of the asbestos contamination, in use the bitumen remover is also recoverable.

Materials resulting from the deconstruction weighed 8,792.51 tonnes, of which the project was able recycle 8,787.41 tonne, giving a recycling rate of 99.94%, the other 0.6% was the ACM that is currently not recyclable.

Unfortunately due to the constricted nature of the site the client was unable to reuse any of the material arisings form the site and so all of it had to be shipped off site for processing.