Case Study // 2-6 Cannon Street

Erith were employed by 4 Cannon Street Limited, advised by Pembroke Real Estate, to carry out the demolition of the former commercial building; Scandinavian House situated on Cannon Street, London. The works would pave the way for a new seven storey office block inclusive of basement, roof top plant and access terrace.

 
The structure consisted of reinforced concrete, masonary cladding with glass infills. The works involved asbestos removal, temporary works, soft strip of fixtures and fittings, removal of all existing mechanical and electrical installations, demolition of the existing building and demolition of an existing building to basement slab level.

The site was surrounded by a number of sensitive receptors including; commercial properties, the Grade I listed Wren Church, Grade II listed Bracken House and most noteworthy of all, adjacent to the iconic Grade 1 listed 17th century St Paul’s Cathedral. With the site being situated on the periphery of St Paul’s Conservation area it was of the upmost importance to ensure the preservation of the tranquil nature of the historic surroundings. In order to ensure there were no disturbances to the surrounding premises, controls were implemented to mitigate the
potential for any noise, dust or vibration pollution, this
included; fire retardant monarflex sheeting encapsulating the building and hoarding around the perimeter.

The structure was progressively stripped from the upper floors down to the basement. Mini machines were then hoisted by a crane onto the highest level of the building to enable the top down demolition sequence to commence. Floor load testing took place prior to the demolition sequence to ascertain what size machinery could be deployed as part of the demolition sequence. Once internal columns were removed, works continued in a repetitive fashion where by 360 degree excavators, complete with pulveriser attachments continued the deconstruction sequence. Floor slabs were propped down to the lowest slab to accommodate abnormal and facility the on-going sequential demolition works in a top-down
fashion. Lastly, a piling platform of 6F2 was constructed to allow for the installation of the permanent bearing piles upon complete demolition of the structural envelope.

All temporary works were undertaken by our in-house design consultants; Swanton Consulting Ltd.