Recommendation of dressing natural building stones

IS 1129: Scope Summary & Key Specifications

Scope:
IS 1129 covers recommendations for dressing (surface finishing) of natural building stones to ensure uniformity and clarity in stone masonry work.

Key Points from Scope and Clause 4.2 (Polishing):

• Dressing involves hand or machine finishing of stones to various degrees based on use and skill.
• Polishing Methods:
  • Manual rubbing with abrasive + water.
  • Machine polishing: Stone held on a revolving table fed with abrasives (sand, corborundum).
  • Final polishing with rubber or felt using putty powder (oxide of lime).

Rough Tooling (Clause 2.4):

• Surface has bands 4–5 cm wide parallel to tool marks.
• Marks can be horizontal, vertical, or 45° angled.
• Edges/corners must be square and true.
• Surface irregularities ≤ 3 mm gap under a straight edge.
• Used for fairly regular plane faces in masonry.

Practical Summary Table:

flowchart LR
    A[Raw Stone] --> B[Dressing]
    B --> C{Type of Dressing}
    C --> D[Rough Tooling]
    C --> E[Polishing]
    E --> F[Manual Abrasive + Water]
    E --> G[Machine: Revolving Table + Abrasives + Putty Powder]

Contact: For detailed specifications or testing, refer to BIS regional offices listed in the standard.

IS 1129: Types of Dressing and Their Characteristics

1. Punched Dressing (Clauses 2.5 & 3.5)

• Surface: Rough tooled surface with depressions formed by punch chisel and hammer.
• Appearance: Series of parallel ridges with visible chisel marks.
• Depth: Gap under a straight edge ≤ 3 mm.
• Use: Provides an even surface.
• Process: Rough tooling → Punching at close intervals → Depth about 3 mm.

2. Closed Picked Dressing (Clause 3.6)

• Surface: Further dressing of punched stone with pointed chisel.
• Appearance: Small pits (~3 mm deep), finer surface with tiny ridges/chisel marks.
• Depth: Checked with straight edge as per Clause 2.6 (similar tolerance).
• Use: For a finer finish than punched dressing.

Summary Table

flowchart LR
    A[Rough Tooled Stone] --> B[Punched Dressing]
    B --> C[Closed Picked Dressing]
    B -->|Depth ≤ 3 mm| D[Parallel Ridges]
    C -->|Depth ~ 3 mm| E[Small Pits & Tiny Ridges]

This concise guide helps identify and specify stone dressing types per IS 1129 for construction use.

IS 1129: Pitched Faced Dressing - Key Specifications & Guidelines

1. Definition & Appearance (Clause 2.1)

• Edges: Level, in the same plane, square with the stone bed.
• Minimum width of pitched dressing: 25 mm around all four edges.
• Surface: Rough, with natural rounded cobble stone left raised.
• Visual Reference: See Fig. 1 (Pitched Faced Dressing Surface).

2. Dressing Method (Clause 3.1)

• Use mason's hammer, club hammer, and pitching tool.
• Dress all edges to achieve the finish described in 2.1.

3. Related Dressing: Punched Dressing (Clauses 2.5 & 3.5)

• Surface shows parallel ridges with chisel marks.
• Depth tolerance: Max gap of 3 mm between surface and straight edge.
• Created by punch chisel and hammer to form depressions ~3 mm deep.
• Used where even surfaces are needed.

Summary Table

flowchart LR
    A[Stone from Quarry] --> B[Pitched Faced Dressing]
    B --> C[Edges dressed with hammer & pitching tool]
    C --> D[Minimum 25 mm dressed edges]
    D --> E[Rough, natural cobble surface]
    A --> F[Punched Dressing]
    F --> G[Depressions with punch chisel]
    G --> H[Parallel ridges, max 3 mm unevenness]

This concise summary aligns with IS 1129 clauses for pitched faced dressing and related finishes.

IS 1129 - Hammer Dressing Summary

Key Specifications:

• Hammer Dressing: Removal of sharp/irregular corners by flat face of scabbling/spalling hammer.
• Surface Dressing: Use pointed end of hammer for final surface dressing.
• Surface Appearance: Even surface, no sharp corners; also called hammer faced, quarry faced, rustic faced.
• Bushing Limit: Maximum 40 mm on exposed face (Clause 2.2).
• Finish Check: Surface should fit well in masonry.

Procedure (Clause 3.2):

1. Knock off sharp corners with flat hammer face.
2. Dress surface with pointed hammer end for evenness.

Related Dressing Types:

• Pitched Faced Dressing (3.1): Edges dressed with mason’s hammer & pitching tool.
• Closed Picked Dressing (3.6): Small pits (~3 mm deep) formed with pointed chisel for fine finish.

Visual Reference (Fig. 2 & 7):

• Hammer dressed stone shows a rustic, evenly rough surface.
• Bushing (roughness) ≤ 40 mm.

flowchart TD
    A[Stone from Quarry] --> B[Remove sharp corners with flat hammer]
    B --> C[Dress surface with pointed hammer end]
    C --> D{Surface evenness}
    D -->|Yes| E[Hammer dressed stone ready]
    D -->|No| C

Note: No explicit formulas in IS 1129 for hammer dressing; focus is on workmanship and dimensional limits.

IS 1129: Rock Facing Key Points

• Definition (Clause 2.3):
  Rock faced stones have minimum 25 mm wide fine chisel marks on all four edges, which lie in the same plane. Used mainly as quoin stones or plinth stones for a robust appearance.

• Surface Treatment (Clause 3.3):

  • Sharp/irregular corners are knocked off with a flat-faced scabbling hammer.
  • Exposed faces are then dressed with fine chisel marks as per 2.3.

• Edge Dressing (Clause 2.1 & 3.1 for pitched faced dressing):

  • Edges must be level, square with the bed, and in the same plane.
  • Minimum 25 mm wide pitched face dressing around edges.
  • Superfluous stone on the face may remain as a natural rounded cobble.

Summary Table for Rock Facing Dimensions

Visual Concept (Simplified)

graph LR
A[Stone Block] --> B{Edges}
B --> C[25 mm wide chisel marks]
B --> D[Edges in same plane]
A --> E[Knock off sharp corners]
E --> F[Flat face scabbling hammer]
A --> G[Surface dressed with fine chisel marks]

Note: IS 1129 focuses on the aesthetic and dimensional requirements rather than structural formulas for rock facing.

Rough Tooling as per IS 1129

Definition:

• Rough tooling produces a surface with bands 4 to 5 cm wide having parallel tool marks.
• Marks can be horizontal, vertical, or at 45°.
• Edges and corners must be square and true.
• Surface may have depressions but the gap under a straight edge ≤ 3 mm.

Key Specifications (Clauses 2.4 & 3.4)

Process Summary (Clause 3.4)

1. Stone is hammer dressed at quarry.
2. Surface layer (~0.3 cm) removed by plane chisel/boaster.
3. Tool marks formed in bands, moving chisel along band direction.
4. Surface tested with mason’s square to meet flatness criteria.

Comparison with Fine Tooling (Clauses 2.7 & 3.7)

flowchart TD
    A[Hammer Dressed Stone] --> B[Remove 0.3 cm Surface Layer]
    B --> C[Form 4-5 cm Bands with Tool Marks]
    C --> D[Test Flatness with Straight Edge (≤3 mm gap)]
    D --> E[Rough Tooled Stone Surface]

Summary: Rough tooling ensures a flat stone surface with characteristic bands of tool marks, suitable for masonry requiring regular planes but not smooth finishes.

Punched Dressing as per IS 1129

• Definition (Clause 3.5):
  Depressions are formed on a rough tooled stone surface using a punch chisel and hammer, creating parallel ridges about 3 mm deep.

• Surface Tolerance (Clause 2.5):
  When checked with a straight edge, the maximum gap between the stone surface and the edge shall not exceed 3 mm.

• Purpose:
  Used where an even surface is required, with visible chisel marks all over.

• Process Summary:

  1. Rough tooling of stone surface.
  2. Punch chisel applied at close intervals, forming parallel ridges.
  3. Surface checked with straight edge for max 3 mm deviation.

Comparison with Closed Picked Dressing:

Visual Concept (Simplified)

graph LR
A[Rough Tooled Stone] --> B[Punched Dressing]
B --> C[Parallel ridges ~3 mm deep]
C --> D[Surface checked with straight edge]
D -->|Max gap ≤ 3 mm| E[Finished Punched Surface]

Key Points:

• Depth of depressions ≈ 3 mm
• Surface flatness tolerance ≤ 3 mm gap under straight edge
• Chisel marks must be visible and parallel
• Used for fairly even stone surfaces, not perfectly smooth

Refer IS 1129 Fig. 5 for typical punched stone surface illustration.

Closed Picked Dressing as per IS 1129:

Key Specifications:

• Surface finish: Finer than punched dressing with very tiny ridges or chisel marks.
• Depth of pits: Approximately 3 mm formed by pointed chisel and hammer (Clause 3.6).
• Straight edge gap tolerance: Maximum 1.5 mm gap between surface and a straight edge (Clause 2.6).
• Purpose: To obtain a finer, more even stone surface than punched dressing.

Summary Table:

Checking Method:

• Use a straight edge placed over the stone surface.
• Measure the maximum gap between the stone and straight edge.
• For closed picked dressing, this gap must be ≤ 1.5 mm.

flowchart LR
    A[Rough Stone] --> B[Punched Dressing]
    B --> C[Closed Picked Dressing]
    C --> D[Final Surface with tiny pits (~3mm depth)]
    D --> E[Check with straight edge]
    E -->|Gap ≤ 1.5 mm| F[Accept]
    E -->|Gap > 1.5 mm| G[Reject or Redress]

This ensures a fine, durable stone surface suitable for precise masonry work.

IS 1129 - Fine Tooling of Stone: Key Points

Definition & Surface Finish (Clauses 2.7 & 3.7)

• Fine tooling is a dressing process after closed picking.
• All surface projections are removed to obtain a fairly smooth surface.
• Surface texture: 3 to 4 lines per cm width, depending on stone hardness and fineness required.
• Commonly used for ashlar work.
• Tools: serrated/claw chisel and mason's or club hammer.

Polishing Process (Clause 4.2)

• Polishing by rubbing with abrasives, wetting surface if needed.
• Alternatively, use a revolving table with abrasives (sand, corundum).
• Final polish with rubber/felt and "putty powder" (oxide of lime).

Summary Table: Fine Tooling Specifications

flowchart LR
    A[Closed Picked Surface] --> B[Fine Tooling]
    B --> C[Remove Projections]
    C --> D[Surface with 3-4 lines/cm]
    D --> E[Polishing]
    E --> F[Final Smooth Finish]

This ensures a durable, aesthetically pleasing stone surface suitable for high-quality masonry.

IS 1129 (1972) - Methods of Dressing Natural Building Stones

Key Dressing Methods & Specifications:

Notes:

• Punched Dressing creates rough depressions for a textured surface.
• Closed Picked Dressing refines this surface by reducing chisel marks to tiny pits.
• Straight edge checks ensure flatness and uniformity as per Clauses 2.5 & 2.6.

flowchart LR
    A[Natural Stone] --> B[Punched Dressing]
    B --> C[Parallel Ridges (~3 mm depth)]
    C --> D[Closed Picked Dressing]
    D --> E[Small pits (~3 mm depth), finer surface]
    E --> F[Straight Edge Check]

This ensures stones have the required texture and flatness for construction aesthetics and bonding.

Pitched Faced Dressing Method (IS 1129)

Key Specifications:

• Edges: Level, in the same plane, square with the bed of the stone.
• Minimum width of pitched face dressing: 25 mm around all four edges.
• Surface finish: Rough, with superfluous stone allowed to remain as natural rounded cobble stone.
• Tools used: Mason's hammer or club hammer and pitching tool.
• Appearance: As shown in Fig. 1 (rough, pitched edges).

Dressing Process (Clause 3.1):

• Dress stone edges immediately after quarrying.
• Use hammer and pitching tool to achieve the pitched finish described in Clause 2.1.

Punched Dressing (Related Info):

• Depressions formed with punch chisel and hammer.
• Depth of depressions: about 3 mm.
• Surface checked with a straight edge; max gap allowed: 3 mm (Clause 2.5).
• Used where relatively even surfaces are required.

Summary Table:

flowchart LR
    QuarryStone -->|Hammer & Pitching Tool| PitchedFace
    PitchedFace -->|Edges 25mm wide| FinishedStone
    FinishedStone -->|If even surface required| PunchedDressing
    PunchedDressing -->|3mm depressions| FinalSurface

This ensures the stone has a robust, rustic pitched edge with controlled roughness.

IS 1129: Hammer Dressing Method - Key Points

• Definition (Clause 2.2):
  Hammer dressed stone has no sharp/irregular corners and a comparatively even surface for good masonry fit. Also called hammer faced, quarry faced, rustic faced.

  • Bushing limit: ≤ 40 mm on exposed faces.
  • Refer Fig. 2 for typical surface appearance.

• Procedure (Clause 3.2):

  1. Knock off sharp/irregular corners using flat face of scabbling/spalling hammer.
  2. Dress the surface using the pointed end of the hammer for evenness.
  • Refer Fig. 7 for fine tooled stone surface.

• Surface Quality Checks:

  • Use a straight edge to verify flatness as per related clauses (2.5, 2.6).
  • Depth of pits or ridges after dressing should be controlled (3 mm for punched/closed picked dressing).

Summary Table for Hammer Dressing

Visual Concept (Hammer Dressing Process)

flowchart LR
  A[Raw blasted stone] --> B[Remove sharp corners with flat hammer face]
  B --> C[Dress surface with pointed hammer end]
  C --> D[Check surface flatness with straight edge]
  D --> E[Hammer dressed stone (bushing ≤ 40 mm)]

This method ensures a rustic yet uniform stone surface suitable for masonry, balancing aesthetics and structural fit.

IS 1129: Rock Facing Method - Key Specifications & Guidelines

• Definition (Clause 2.3):
  Rock facing involves dressing stone with a minimum of 25 mm wide fine chisel marks along all four edges, which must lie in the same plane. This gives a rugged, solid appearance used mainly for quoin stones and plinths.

• Surface Preparation (Clause 3.3):

  • Knock off sharp/irregular corners using a scabbling hammer's flat face.
  • Dress the exposed face with fine chisel marks as per 2.3.

• Edge Dressing (Related - Clause 2.1 & 3.1 for pitched faced dressing):

  • Edges must be level, square with the bed, and at the same plane.
  • Minimum width of dressed edges: 25 mm.
  • Superfluous stone may remain as a natural rounded cobble stone.

Summary Table for Rock Facing

flowchart TD
    A[Stone from Quarry] --> B[Knock off sharp corners with scabbling hammer]
    B --> C[Chisel edges with 25 mm wide fine marks]
    C --> D[Edges leveled & in same plane]
    D --> E[Rock faced stone ready for masonry use]

This ensures strength, solidity, and aesthetic ruggedness in stone masonry per IS 1129.

IS 1129: Rough Tooling Method Summary

Key Specifications (Clauses 2.4, 3.4)

• Surface bands: 4 to 5 cm wide, parallel tool marks (horizontal, vertical, or 45° angle).
• Surface depth tolerance: Max gap under a straight edge ≤ 3 mm.
• Surface removal: Top layer ~ 0.3 cm thick removed using plane chisel/boaster and hammer.
• Edges & corners: Must be square and true.
• Surface finish: May have depressions; fairly regular plane faces suitable for masonry.

Procedure Highlights (Clause 3.4)

• Hammer-dressed stone from quarry.
• Remove 0.3 cm layer by forming bands of tool marks.
• Boaster/chisel moves along band direction.
• Test surface regularly with mason’s square.

Additional Notes

• Rough tooling produces a textured surface with visible tool marks.
• Used where a regular, but not smooth, stone face is acceptable.
• Punched dressing (Clause 3.5) adds ~3 mm deep depressions for ridges.

Visual Concept (Fig. 4 Rough Tooled Surface)

graph LR
A[Stone Surface] --> B[Series of 4-5 cm wide bands]
B --> C[Tool marks parallel]
C --> D[Orientation: Horizontal / Vertical / 45°]
D --> E[Max gap under straight edge ≤ 3 mm]

This method ensures a controlled roughness and flatness for masonry stones per IS 1129.

IS 1129: Punched Dressing Method - Key Specifications

• Definition (Clauses 3.5 & 2.5):
  Punched dressing involves creating depressions (~3 mm deep) on a rough tooled stone surface using a punch chisel and hammer, forming parallel ridges.

• Surface Tolerance:

  • Depth of gap under a straight edge: ≤ 3 mm
  • Ensures relatively even surface with visible chisel marks (Fig. 5).

• Purpose:
  Used where an even but textured stone surface is required.

Closed Picked Dressing (for finer finish):

• Further pits (~3 mm deep) are formed on punched stone (Clauses 3.6 & 2.6).
• Surface tolerance: ≤ 1.5 mm gap under straight edge.
• Results in very fine ridges/chisel marks (Fig. 6).

Summary Table

flowchart LR
    A[Rough Tooled Stone] --> B[Punched Dressing]
    B -->|3 mm pits| C[Parallel ridges, ≤3 mm gap]
    C --> D[Closed Picked Dressing]
    D -->|Finer 3 mm pits| E[Tiny ridges, ≤1.5 mm gap]

Check surface flatness with a straight edge as per IS 1129 requirements.

Closed Picked Dressing Method (IS 1129)

• Definition (Clause 2.6):
  Further dressing of punched stone to obtain a finer surface with very tiny ridges or chisel marks.

  • Tolerance: Gap between surface and straight edge ≤ 1.5 mm (Fig. 6).

• Process (Clause 3.6):
  Use a pointed chisel and mason's/club hammer to form small pits ~3 mm depth for a finer surface.

  • Check flatness with a straight edge as per Clause 2.6.

• Comparison with Punched Dressing:

  • Punched Dressing (Clauses 2.5 & 3.5) forms parallel ridges with ~3 mm depth depressions.
  • Flatness tolerance for punched dressing is ≤ 3 mm gap under straight edge (Fig. 5).

Summary Table

Visual Concept (Fig. 6 Closed Picked Surface)

graph LR
A[Stone Surface] --> B[Small pits ~3mm depth]
B --> C[Tiny ridges/chisel marks]
C --> D[Checked with straight edge]
D --> E{Gap ≤ 1.5 mm}

Key takeaway: Closed picked dressing produces a finer, more even stone surface than punched dressing, with tighter flatness control (1.5 mm max gap).

Fine Tooling Method (IS 1129)

• Definition (Clause 2.7 & 3.7):
  Fine tooling is a surface dressing where a closed picked stone surface is further dressed with a serrated or claw chisel and hammer to remove all projections, producing a fairly smooth surface.

  • Surface finish: 3 to 4 lines per cm width, depending on stone hardness and fineness required.
  • Commonly used for ashlar masonry.

• Procedure:

  1. Start with a closed picked surface (all projections roughly removed).
  2. Use a serrated/claw chisel and mason’s or club hammer to remove remaining projections.
  3. Achieve a smooth surface with fine parallel lines.

• Comparison:

  • Rough tooling (Clause 2.4) has bands 4-5 cm wide with visible tool marks and up to 3 mm depth irregularities.
  • Fine tooling is smoother with finer lines (3-4 per cm).

• Polishing (Clause 4.2):

  • Final polishing can be done by rubbing with abrasives and water or on a revolving table with abrasives like sand or corundum.
  • Finish with rubber/felt and putty powder (oxide of lime).

Summary Table

flowchart TD
    A[Closed Picked Surface] --> B[Fine Tooling]
    B --> C{Surface Finish}
    C -->|3-4 lines/cm| D[Fairly Smooth Surface]
    D --> E[Polishing (optional)]
    E --> F[Final Smooth & Polished Stone]

Note: Fine tooling improves aesthetics and stone fit in masonry, essential for visible ashlar stonework.

Polishing of Stones (IS 1129 - Clause 4.2)

Methods:

• Manual Polishing:

  • Rub stone with suitable abrasive.
  • Wet surface with water if necessary to aid polishing.

• Mechanical Polishing:

  • Hold stone firmly on a revolving table.
  • Feed abrasive material like sand or corundum onto the table.
  • Final polishing by rubbing with rubber or felt using putty powder (oxide of lime) as polishing medium.

Key Specifications:

Additional Notes:

• Polishing improves stone aesthetics and durability.
• Abrasive grain size and polishing duration depend on stone type and desired finish.
• Ensure firm holding of stone during mechanical polishing to avoid uneven finish.

flowchart TD
    A[Stone] --> B{Polishing Method}
    B -->|Manual| C[Rub with abrasive + water]
    B -->|Mechanical| D[Stone on revolving table]
    D --> E[Feed abrasive (sand/corundum)]
    E --> F[Final polish with rubber/felt + putty powder]
    F --> G[Polished stone surface]

For detailed tooling and surface finish, refer to Clauses 2.4, 3.4, and 3.7 of IS 1129.