There are three ways to clean any surface- you can either use chemicals, agitation, or heat. In the softwashing industry biocides deliver chemical cleaning, pressure washers deliver agitation, and steam cleaning systems deliver heat. It is vital to use a good quality steam washing system when cleaning a surface. This is because many substrates will only be able to withstand a certain temperature, and only good quality steam cleaning systems can strictly control temperature.
The most highly recommended steam washing system is the Doff Steam Integra System from Stonehealth. This technology was developed for conservation and restoration. It produces uses steam at low pressure- so it therefore minimises damage- and the temperature can be determined to the nearest degree- meaning it can safely be used on any surface if the heat tolerance is known. The technology is recommended by many heritage organisations, including the Victoria Cross Trust and Historic England.
Doff Steam cleaning is particularly effective for stone restoration making it ideal for use on monuments, memorials, and statues. Common masonry substrates, such as limestone, granite, and sandstone, respond excellently to Doff Steam cleaning, as does polished concrete and resin bound flooring. Substrates like cladding and render can also be steam washed using a Doff machine. This can supplement, and in some instances replace, chemical cleaning.