St Paul's Cathedral

This project was awarded Commended in the Repair and Restoration category at the Natural Stone Awards 2006.

The official guide said, 'Following a five-year period when tests were carried out to find the best way of cleaning the Portland limestone interior of St Paul's Cathedral it was determined that Arte Mundit, a latex-bound EDTA (ethylenediaminetetraacetic acid), should be used. The project started in April 2001 and finished in may 2005 - without interrupting the daily life and work of the Cathedral either as a place of worship or tourist attraction. That meant high level bridging and suspended scaffold lifts to minimise disruption at floor level.

Work on the famous dome required a rotating scaffold 14-storeys high. First, layers of dust of as much as 25mm thick were cleaned off. Then the Arte Mundit was spray applied and peeled off after 24-to-48 hours. The stone was sprayed with a light mist of water and scrubbed with various brushes, sponged and rinsed again. Unfinished replacement stones were carved and missing stone inserted.'

The judges commented, 'This enhancement to St Paul's Cathedral combines aesthetic, academic and intellectual rigour to reveal the original glorious vision in the face of determination to overcome the labyrinth of bureaucracy.'

To view this project in more detail, please click here.

St Pauls Cathedral using Portland Stone