F I N I S H I N G   S P E C I F I C A T I O N S

The Irish Blue Limestone has a tight consistent grain structure that contributes to the excellent performance as a building stone but also makes it an attractive material to the stone mason. The absence of a pronounced 'grain' enables the mason to work the stone at will and has fostered the tradition of applying decorative finishes to the exposed surfaces of ashlar.    

Hand dressing without the assistance of modern pneumatic chisels is an arduous procedure and the traditional finishes applied to the limestone were mainly associated with shaping the blocks and imparting a degree of uniformity. Fine tooling and the carving of ornate detailing was for a long time limited to door and window surrounds and the interior of prestigious buildings. Advances in metallurgy accompanied by the development of powered cutting tools during the latter part of the 19th century brought sweeping changes to the industries working stone. Ashlar could be cut to size and the traditional skills of the mason could be devoted to the aesthetics of the ashlar rather than the basic manufacturing.    

Traditional surface finishes that would have been used sparingly at one stage can now be applied to all the ashlar within a building. This ability opens a completely new field to the architects.

The coarser dressings, which were originally associated with the shaping of the ashlar, bring out the dark natural colour of the Irish Blue Limestone with the surface fleck of the calcite crystals being the only ornamentation. Finer tooled finishes give a much warmer pale blue grey colour and can in some cases emphasise the fossils and calcite crystals. The scope with the finer finishes, however, goes far beyond just the paler colour. The orientation of the pattern, left by the tool used for the finish, can give a subtle interplay with the light falling on the building. Changes in pattern or alignment can be used as decorative features in their own right.    

Technology has transformed a basic commodity into a highly versatile material that can complement the skills of the architect. Cladding substantially increases the versatility of the Irish Blue Limestone as the traditional finishes and appearance only achieved by natural stone can be successfully combined with the benefits of modern construction methods.

The Irish Blue Limestone producers can supply a very wide range of finishes and dressings as ashlar and cladding. There are however some practical limitations imposed by the finish or dressing applied to the surface of limestone. Any dressing of the surface requires the input of energy. The amount of energy is almost directly proportional to the relief of the final surface and will be reflected in the minimum thickness of limestone that can be used in the manufacturing process. As a wide range of manufacturing equipment is employed in the Irish quarries, the minimum thicknesses, indicated below, for each dressing or finish, should be verified with the supplier at an early stage in the design process. Individual producers may not have the necessary equipment to offer all the dressings and finishes outlined in the following pages and availability should also be checked.    

The creation of a dressing or finish on the surface of the ashlar or cladding will require both equipment and skilled manpower. This will result in additional costs that can be quite substantial for some dressings. The figures indicated below provide a guide to the likely cost increase as opposed to the basic sawn finish. The ratio of the cost is relative to the basic sawn cladding or basic sawn ashlar and does not relate to the relative cost of cladding as opposed to ashlar.