USING Coca-Cola or similar drinks to remove rust-like residue from stainless-steel roofing is one of a series of tips recommended by Historic England (HE) in advice to churches this month.
The guidance is the result of an independent survey of installations in England over the past 25 years, after some churches that turned to steel after attacks by lead-thieves experienced problems, including leaking seals and excessive noise during heavy rain.
While Historic England prefers like-for-like replacement, especially for particularly important buildings or highly visible locations, it acknowledges that the most durable alternative to lead is terne-coated stainless steel (TCSS). Terne, French for “dull”, is the word used for a thin metallic overlay, which, over time, weathers to an appearance close to lead. These days, that is usually tin, but earlier installations had a coating that included lead, and was prone to discolouration. The guidance recommends the “a weak phosphoric acid solution that is commonly found in carbonated soft drinks, especially cola”.
Other problem-solvers include the use of acoustic matting to cut rain noise, new methods of joining the steel sheets, and using lead for smaller awkward-shaped or irregular sections.
The new guidance was welcomed by the Church of England’s Church Buildings Council, which has long regarded TCSS as an acceptable alternative to lead on historic buildings. “The practical note on installation and noise reduction is a welcome support for churches considering a stainless-steel roof,” the Church’s senior church buildings officer, David Knight, said. “We welcome this newly published research that shows that terne-coated stainless steel is a realistic material in place of lead for use on historic buildings.
“It is less attractive to thieves, having a lower value and being difficult to remove, while still giving buildings lasting protection from the weather. Churches with a lead roof who are concerned about its potential theft, or seeking to replace lead which has been stolen or damaged, are encouraged to see the HE and Church of England guidance on security and church roofs, and to consult with their DAC.”
A spokesperson for Ecclesiastical Insurance said: “From an insurer’s perspective, costs of using stainless steel would be covered provided they did not exceed the cost of the equivalent in lead. However, churches will need to go through the faculty process with their DAC to get permission to replace lead roofing with an alternative material. For secular listed buildings, Listed Building Consent will be required.”