This part of BS 5385 gives recommendations for the design and
installation of external ceramic and mosaic wall tiles in normal climatic
conditions in the UK. It deals with the types of backgrounds and their
suitability to receive tiling using the following fixing methods:
a) bedding in cementitious or organic adhesives on an intermediate
substrate or as a direct bedding method;
b) bedding mosaics in cement:sand mortar on rendering or as a direct
bedding method.
NOTE Cement:sand mortar is seldom used as the bed for external wall
tiling but, if needed, see BS 5385-1.