The cleaning of a building is no simple matter and there are special considerations which call for a high degree of expertise in all elements and at all stages of stone cleaning. Specialised knowledge is necessary for the correct specification to be given for each building.

In the past, it was smoke emissions for the burning of coal that caused the soiling of buildings. Today it is vehicle exhausts and acid rain that are mainly responsible. Many studies have shown there are advantages for cleaning buildings on a regular basis.

This guide is concerned with the cleaning of natural stone, much of which forms the architectural heritage of the country.

Stone is one of the most durable of all building materials and compares favourably with others from an economic as well as an aesthetic point of view, especially when maintenance and whole life costs are taken into account.

Nevertheless, proper maintenance is essential and if this is carried out periodically with suitable skill and understanding, the greater will be the environmental and practical advantages in the preservation of the structure.

What must be stressed, however, is that in the wrong hands and by the use of the wrong processes for the materials in question, much harm can be caused, with unsightly effects resulting, some of which may not become apparent for months after the cleaning has been completed and which will be difficult, if not impossible, to remedy.

And it should be remembered that while this new Guide aims to give advice, it is not definitive. Variables exist with every project and no two projects are the same. This is why it is imperative to involve a member of Stone Federation at an early stage when the cleaning of a stone building is being considered.

It is essential that cleaning should be carried out by fully trained operatives in order to avoid any damage being caused by an inappropriate cleaning method or an incompetent operative. Remember decay can often take place around an open joint or cracked stone which cannot be seen when obscured by dirt or heavy soiling.

This Guide relates to natural stone, however, Stone Federation members who carry our stone cleaning are also knowledgeable in cleaning brickwork, concrete, terracotta and other materials and they are also covered in this Guide.

This is just the latest good practice guide from Stone Federation Great Britain. Please visit our publications section for a complete list.