Structural Waterproofing

The American School in London

The American School campus in St Johns Wood is on a compact site with little room for expansion. A concept for a new pool and fitness centre was designed by ORMS Architecture. This enabled the school to receive first class facilities built underground; just below the playground and just above the Jubilee line.

This project was planned in intricate detail allowing only sections of the basement to be constructed at a time to avoid any disturbance to the Jubilee line and the surrounding sub soils. The risk involved with excavating so close to a tube line meant only certain amounts of sub soil could be excavated at once. FIS were able to design a waterproofing system which would provide a Grade Three basement in accordance with BS8102:2009, meet the contractors budget and be practical for installation with small concrete pours.

A waterproof concrete design using Premcrete Hydrocrete and Premcrete Hydrostop BR hydrophilic waterbars was developed by the CSSW qualified design team at FIS. This meant that the contractor did not have the concern of continuity of membrane. Had a membrane been used the project’s programme would have suffered due to the number of pours and therefore the increased lap detailing and required quality control prior to each pour.

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