New guidance on how to clean Bath Stone

Bath & North East Somerset Council has worked with the Bath Preservation Trust to produce new guidance about cleaning the famous Bath stone.

Most of the city’s buildings are built from the stone which weathers to an attractive, creamy honey colour, but it is soft and crumbles easily and so must be cleaned sensitively.

The Conservation Advice Note ‘The Cleaning of Bath Stone’  will help building owners, applicants for listed building consent and their agents pick their way through some of the problems associated with stone cleaning.

Cllr Bryan Chalker, Bath & North East Somerset Council Chairman and Heritage Champion, said: “With a number of properties coming up for their second or even third round of cleaning I have encouraged the Historic Environment team to provide up-to-date guidance on this sensitive subject. This will help avoid both preventable distress to stonework and unnecessary expense by building owners.”

“Dirty stonework can be damaging to the aesthetic character of the architecture and to its long-term preservation,” said Ian Lund, the Council’s Historic Environment Team Leader.  “Cleaning is therefore desirable in many cases. However, insensitive stone cleaning can cause unnecessary damage to historic buildings.

“In response to commercial pressures the number of mechanical and chemical cleaning techniques available has expanded in recent years. The document looks at how to minimise risk by ensuring reputable contractors are involved. Only companies that see stone cleaning as inseparable from the maintenance of the whole façade, and who can offer a range of techniques, should be engaged.”

Joanna Robinson, Conservation Officer with Bath Preservation Trust, said: "The build up of atmospheric pollutants, now primarily from vehicle exhausts, can disguise the natural beauty of Bath stone and cause damage to mellow facades and delicate ornament. However cleaning itself can do more harm than good, over cleaning and using the wrong methods can erode the stone, damage fine details, cause damp problems and can actually cause the build up of even more dirt. Stone cleaning is a complex issue and this guidance helps to address the fundamental questions,  most of all,  is cleaning really necessary? The Trust endorses the guidance and hopes that there will be further collaboration on conservation advice notes for other subject matters."

Copies of the document are available from the Council's website at www.bathnes.gov.uk  - search under Environment and Planning in the A – Z index, then Conservation / Conservation Guidance leaflets. You can also find it on the Trust's website at www.bath-preservation-trust.org.uk