Terracotta and faience are both formed from ground clay mixed with sand or powdered fired clay which has enough plasticity that it can be moulded into a shape.
The difference between terracotta and faience is that faience is covered with one or more glazes whereas terracotta is not.
During the late 19th century, expansion of Salford it became fashionable to construct buildings in terracotta and faience. Mass production allowed for highly decorative design to be marketed cheaply and for heavy materials such as this to be transported long distances from the factories in which they were made.
Today terracotta and faience facades very much defines the hay day of large industrial cities such as Salford and are therefore incredibly important to the city's heritage, with several of our listed buildings being designated because of their fine terracotta and faience designs.
This material, however, is very delicate and cannot withstand minor impacts or changes in structural stresses caused by expanding embedded ironwork or new loadings.
One of the most significant properties of terracotta is its irreplaceable fire skin, which when removed, as a result of inappropriate cleaning for example, leaves terracotta vulnerable to soiling and deterioration.
The same is true of the glaze applied to faience. There is a general presumption against cleaning in most cases, however if a particular case is justified then there are three cleaning systems that the city council will consider.
Repair of terracotta and faience is possible but will require specialist technical expertise.
Historic Scotland has published guidance on terracotta and faience which can be downloaded below
If you are unable to view documents of these types, our downloads page provides links to viewing software.