Nick Leach, Repairs Manager for the Diocese, shares the incredible process of cleaning and repairing the outside of a 130 year old vicarage.
St Barnabas Church and Vicarage was designed by Thomas Cundy Jr and constructed around 1850. Built in a modern gothic style, it has a Grade II Statutory Listing, granted in 1970, meaning it is protected and any work to it must be authorised via granting of Listed Building Consent. The property is built largely from Kentish Ragstone which – as its name implies – comes from Kent, and would have been shipped to London along the Thames. It is the same stone that The Tower of London is built from, as well as Maidstone prison. The property also has Bath Stone dressings on the quoins and windows. Its style is in stark contrast to the smart stuccoed dwellings built by Cubitt around the adjacent areas of Pimlico.
The issues
Unfortunately, decades of exposure to smoke from coal fires, and then car exhaust fumes, had left building covered in grime – particularly the north elevation. This grime chemically binds itself to the stone, and as the building is sheltered by the church on this elevation it gets far less rainfall to wash it off. There had also been issues with leaks to the stairwells below the turrets for some time. Additionally, the building has undergone a number of unsuitable cement-based pointing repairs over the years, leading to spalling of the Bath Stone (where the stone breaks away).
What we did
Listed Building Consent was granted, with the condition that any repairs were carried out using sympathetic materials.
O’Hanlon & Sons were appointed as our main contractor. A small area of the masonry was cleaned as a test, with much better results than anticipated. A fully encapsulated scaffold was erected in July and a six-week programme of work agreed with O’Hanlon. Two methods of cleaning were used, the first being a blast clean, where a medium softer than the stone but harder than the grime is fired onto the surface; this was used on the Ragstone. The second method was a DOFF clean (using a Doff machine), which is a gentle system of steam cleaning; this was used on the Bath Stone.
Once the clean was completed, the masons started repairs to the stone turrets, which had been leaking for some years and had suffered from the inappropriate repair techniques. These were rectified and left watertight. The cement pointing to the masonry was removed and reinstated with a traditional lime mortar meaning that moisture can be wicked away from the stone, rather than being trapped within it adding to the potential of frost damage.
The works were completed on time and within budget, the results speaking for themselves, although the last word comes from the Vicar, Jonathon Pearson-Hicks:
‘When the Clergy House was built in 1847 the architects wanted to bring ‘God’s glory to this corner of Pimlico’. Following the recent external renovations to the stone work we feel our building has had decades of soot, grime and oxidization removed to reveal beautiful stone work and detailing. It really is a beautiful building and since the recent revelations, people ask, ‘what is it like to live in a castle? Wonderful. Thank you to Nick Leach and the team.’
