The repair and protection of an iconic, listed church structure in the heart of Catford

Location: Catford, London

History of the project
St Laurence Church is located in the South-East of London within the busy hub of Catford town centre. The building comprises a combination of an original octagonal concrete frame structure completed with an intricate dome construction, and modern brickwork construction for the remainder of the property. JBSR were engaged during the project planning stages in order to discuss sympathetic repair methodologies in addition to liaison and satisfaction of the Twentieth Century Society conservation body involved with the project. The principle design feature of the structure is the incorporation of Dalle de Verre glazing retained by slim mullion sections between the structural frame elements. The fragile nature of this glazing in close proximity to defective concrete retaining mullions added complexity to the project, requiring additional care and consideration in order to mitigate the risk of damages to these iconic elements of the structure.

Project Specifics

Following our early involvement, JBSR were successful in the award of the concrete repair and protection works to both internal and external elements of the original structure. The scheme required continual liaison with the church management to accommodate works around the sensitive use of the building, while also managing closely the financial aspects of the project via regular cost forecasts to ensure the budget was not exceeded. During internal elements of the project, JBSR sought to utilise mobile access provisions to enable removal of access for evening and weekend periods to enable minimal disruption to planned worship and group meetings.

The scheme of works included:

Early contractor engagement with material manufacturers, to agree the material specifications in order to satisfy the project performance and financial criteria.
Provision internally of localised access to ensure minimal disruption to the church operations, while ensure safe access to the respective elements of the façade for both our operatives and building users in close proximity to the works.
Full conditional survey of all concrete elements to identify any in-situ defects within the substrates.
Breaking out, preparation and subsequent making good of all defective concrete elements, to provide a uniform finish matching existing lines and levels utilising proprietary repair mortars in readiness for subsequent application of protective coatings. Due to the fragile nature of the Dalle de Verre panels and slim design of their retaining mullions, considerable care and additional protection was given during the breaking out operations to mitigate risk of damage to the historic and iconic Dalle de Verre glazing.
Installation of polysulphide jointing materials at the junction of the Dalle de Verre Glazing and concrete mullions, offering protection against water ingress and expansion cracking.
Application of specialist elastomeric anti-carbonation coatings to concrete elements to provide additional protection against atmospheric effects on the substrate.