Recommendation of dressing natural building stones
1972 Edition

According to IS 1129 (1972), natural stone dressing is classified based on finishing level and tools used. The main types consist of: Pitched Faced Dressing, where edges are dressed with mason's or club hammer and a pitching tool to achieve a rough, angled finish; Rough Dressing, which involves basic shaping and coarse surfaces; Hammer Dressing, achieved by hammer blows to create a more uniform face; Fine Dressing, which uses chiseling and grinding for a smoother finish; and Polished Dressing, resulting in a smooth and glossy appearance. These classifications help standardize terminology and techniques across the stone masonry industry.

Hammer Dressing, as outlined in IS 1129, refers to producing a relatively even stone surface free from sharp or irregular corners by using the flat side of a scabbling hammer to remove edges, followed by dressing with the hammer's pointed end. It is also called hammer faced or rustic faced, with a maximum bushing of 40 mm on exposed surfaces. In contrast, Rock Facing involves knocking off sharp corners similarly but leaving the exposed surface with a more natural, rugged look created by fine chisel marks at the edges. Rock Facing results in a less uniform but robust appearance, often used for quoin stones and plinths.

IS 1129 specifies that punched dressing should have parallel ridges with chisel marks and a maximum gap of 3 mm between the stone surface and a straight edge, with depressions approximately 3 mm deep. Closed Picked Dressing is a finer finish where tiny pits about 3 mm deep are formed, and the allowable gap under a straight edge is reduced to 1.5 mm. These tolerances ensure a consistent and even surface suitable for stone masonry.

For fine tooling, IS 1129 recommends starting with a closed picked stone surface. The surface is then further dressed using a serrated or claw chisel combined with a mason's or club hammer to remove all projections, creating a fairly smooth finish. The resulting texture typically features 3 to 4 tool lines per centimeter, depending on stone hardness and desired finish. This method is commonly used in ashlar masonry and may be followed by dragging or combing to further refine the surface.

Per IS 1129 Clause 4.2, polishing of natural stones can be performed manually by rubbing the stone surface with suitable abrasives, wetting it with water if necessary. Alternatively, mechanical polishing involves securing the stone on a revolving table while feeding abrasives such as sand or corundum onto the surface. The final polishing step uses rubber or felt along with 'putty powder' (oxide of lime) to achieve a smooth, glossy finish. This process enhances both the aesthetic and durability of the stone.