Applied finishes fall into two categories:
- Those applied after manufacture,
- those applied during manufacture.
Finishes applied after manufacture are predominately paint systems, to which precast concrete lends itself most successfully. Paint finishes have become popular in recent years and can produce a colourful, economical unit with consistent appearance. Previously they were used more for functional or architectural reasons, such as to produce an even colour when insitu and precast concrete were combined in the same facade. This can still be a valid reason for using such a finish.
The process for painted finishes usually involves three steps, 1 primer, 2 texture and 3 finish coats. The texture stage may produce a range of surfaces from smooth to stippled to stucco, while the finish coats provide the colour and weathering properties.
Finishes applied during manufacture include brick biscuits, tiles and dimension stone. It is important to carefully select the applied material to ensure it will bond successfully with the concrete backing, particularly where tiles are involved. In the case of dimension stone, however, bonding is to be avoided because of thermal expansion differences in the two materials, in which case they are connected mechanically.
