Dulwich College has begun work on upgrading the main Charles Barry Jnr buildings in time for the quater centenary of the foundation of the School in 2019, with work to all three of the main blocks. The scale and volume of the intricate architectural detailing that embellishes the facades may not always be fully appreciated from ground level but it is this that make the buildings historically important. Charles Barry Jnr, the architect, was one of the first Victorian architects to use terracotta on such a scale. He recognised its value for mass-producing ornament and fine masonry by casting from an original - combining new technology with traditional craftsmanship. The material offered a new approach to style and decoration, founded on historic precedent - one that suited the Victorian outlook. He wrote many papers on its benefits – the material was light and easy to transport, it was strong in compression, and, probably most importantly, it was cheaper than stone, particularly for the production of repeated decorative elements; and that its smooth, fired surface was more dirt resistant - an important consideration in the filthy urban environment at the time.
While it was at the forefront of Victorian technology, 150 years of exposure to the weather, intermittent maintenance, bomb damage, and the use of iron bars rather than stainless steel to connect sections together, meant that much of the terra cotta was in poor condition. The facades are being cleaned, using the latest conservation techniques to minimise damage and remove years of soiling – to reveal the original colour and finish. The majority of the repair work is concentrated at roof level on the Central Block and covers the brick and terracotta turrets, the finials, and the pierced terracotta balustrade that runs around the complete perimeter of the building.
The specification and scope of works was developed during a series of external inspections, a combination of ground and roof level visual surveys, and mobile vehicle platform access. Highly detailed elevation drawings indicating the extent and location of work to be carried out were made. Replacement terracotta is being manufactured following traditional techniques using examples taken from site used as models to form plaster moulds. Where this isn’t possible, clay models are hand crafted from detailed drawings and site profiles. Clay is hand pressed into the moulds and allowed to dry before placing in a kiln for firing at around 1000ºC.
The main contractor for the project is PAYE Ltd, a well know stone restoration company, and the terracotta is being supplied by Hathern Terra Cotta, the successor to the Hathern Station Brick & Terra Cotta Company, established in 1874 in Loughborough, Leicestershire – and now owned by the Michelmersh Brick Holdings Ltd. It’s good to see in this Brexit era that we still make some things at home!