Code of practice for construction of stone masonry, Part 2: Ashlar masonry

IS 1597 Part 2: Scope & Key Specifications

• Scope Exclusions (Clause 1.3):

  • Stone facing and veneering work.
  • Masonry for dams and other specialized masonry.

• Definitions:

  • Refer to IS 1597 (Part 1): 1992 for stone masonry terminology.

• Rounding Off (General):

  • Final test or calculated values must be rounded per IS 2:1960.
  • Retain significant figures equal to those in the specified values.

• Setting Out (Clause 8.1):

  • Follow IS 2212:1991 Clause 8 for layout and setting out procedures.

• Essential Information for Design & Execution (Clause 4):

  • Layout plan with structure orientation.
  • Dimensioned details: sections at 1:20 scale, foundation & floor levels, room heights, openings.
  • Material details: stone type, masonry class, bond types, mortar mix, finishes.
  • Service provisions: openings, chases, embedments for utilities, hearths, flues, chimneys.

Summary Table: Information Required for Stone Masonry Works

flowchart TD
    A[Start: Project Planning] --> B[Collect Layout Plan]
    B --> C[Dimensioned Details]
    C --> D[Material & Mortar Specifications]
    D --> E[Service Lines & Openings Details]
    E --> F[Execution & Quality Control]

This ensures compliance and clarity in stone masonry construction per IS 1597 Part 2.

IS 1597 Part 2: Referenced Standards Summary

Key Referenced Indian Standards:

Important Notes:

• Rounding Off: Use IS 2:1960 rules for rounding numerical values—retain significant figures equal to those specified.
• For structural stability and strength, refer to IS 1905:1987, IS 1893:1984, and IS 4326:1976.
• Dressing details for stone masonry follow IS 1129:1972.

Quick Reference for Structural Stability:

flowchart LR
    A[IS 1597 Part 2] --> B[Stone Masonry Construction]
    B --> C[Refer IS 1129 for Dressing]
    B --> D[Refer IS 1597 Part 1 for Rubble Masonry]
    B --> E[Structural Stability & Strength]
    E --> F[IS 1905 (Unreinforced Masonry)]
    E --> G[IS 1893 (Earthquake Design)]
    E --> H[IS 4326 (Earthquake Construction)]

For detailed design

IS 1597 Part 2: Definitions & Key Specifications

• Definitions: Stone masonry definitions are as per Clause 3 of IS 1597 Part 1:1992. This includes terms like rubble masonry, ashlar masonry, and various bonds.

• Rounding Off: All test or analysis results must be rounded per IS 2:1960 rules, retaining the same significant figures as specified values.

• Scope Exclusions:

  • Stone facing and veneering.
  • Masonry for dams or other specialized masonry.

• Essential Information for Design & Execution:

  • Layout plan with structure orientation.
  • Detailed dimensioned drawings at scale 1:20.
  • Stone type, masonry class, bond type, mortar mix, and finish details.
  • Openings, chases, embedments for services, hearths, flues, chimneys.

• Damp-proof Course: Refer to Clause 6.8 of IS 2212:1991 for materials and placement.

Summary Table of Key References

flowchart TD
    A[Start: Stone Masonry Project] --> B[Collect Layout Plan]
    B --> C[Prepare Dimensioned Drawings (1:20)]
    C --> D[Specify Materials & Masonry Class]
    D --> E[Detail Openings & Services]
    E --> F[Refer to IS 2212 for Damp-proof Course]
    F --> G[Execute Masonry Work as per IS 1597]

This ensures compliance with IS 1597 Part 2 for stone masonry definitions and specifications.

IS 1597 Part 2: Necessary Information for Planning and Execution

Key Information to be Furnished (Clause 4)

For effective planning, design, and execution, provide:

• Layout plan: Orientation of the structure.
• Dimensioned details: Sections at scale 1:20 (1 cm = 20 cm), foundation levels, finished ground levels, floor-to-floor heights, sizes of openings.
• Material & workmanship:
  • Type of stone & masonry class.
  • Types of bond and final finish.
  • Mortar mix details (refer IS 1597 Part 1, Clause 7.4).
  • Architectural features, mouldings, special work.
• Service provisions:
  • Location/details of openings, chases, embedments for water, drainage, electrical lines.
  • Hearths, flues, chimneys.

Structural Stability & Strength (Clause 7.6.1)

Refer to:

• IS 1905:1987 (Masonry design)
• IS 1893:1984 (Earthquake resistant design)
• IS 4326:1976 (Earthquake resistant construction)

Setting Out (Clause 8.1)

Follow Clause 8 of IS 2212:1991 for setting out procedures.

Mortar Types (Clause 7.4)

Refer IS 1597 Part 1, Clause 7.4 for mortar types and mix proportions.

flowchart TD
    A[Necessary Information] --> B[Layout Plan]
    A --> C[Dimensioned Details]
    A --> D[Material & Workmanship]
    A --> E[Service Provisions]
    D --> F[Stone Type & Masonry Class]
    D --> G[Bond & Finish]
    D --> H[Mortar Mix]

This structured information ensures clarity and smooth execution in stone masonry projects per IS 1597 Part 2.

IS 1597 Part 2 – Materials: Key Points

• Rounding off values: Follow IS 2:1960 for rounding test results, keeping the same significant figures as specified.

• Damp-proof course materials: Refer IS 2212:1991 Clause 6.8 for material selection and placement.

• Materials for ashlar masonry: Use materials as per IS 1597 Part 1, Clause 5.1.

• Stone selection: Based on intended use; see Table 2 of IS 1597 Part 1:1992 for recommended stone types for various applications.

• Mortar types: Use mortar types specified in IS 1597 Part 1, Clause 7.4.

Summary Table from IS 1597 (Part 1) - Table 2 (Typical Stone Uses)

Mortar Types (IS 1597 Part 1 - Clause 7.4)

• Type A: Cement mortar (1:3 cement:sand) – for heavy load-bearing masonry.
• Type B: Lime mortar (1:2 lime:sand) – for non-load bearing or historic structures.
• Type C: Cement-lime mortar (1:1:6 cement:lime:sand) – general purpose.

For detailed material specs, always cross-check IS 1597 Part 1 and IS 2212 as referenced.

Selection of Stone as per IS 1597 (Part 2) & IS 1597 (Part 1):

• Reference: Clause 6 of IS 1597 (Part 2) refers to Table 2 of IS 1597 (Part 1):1992 for recommended stone types based on usage.

• Key Considerations:

  • Stone type must suit the environmental exposure (weathering, moisture).
  • Consider load-bearing capacity, durability, and aesthetic requirements.
  • Use stones as per their recommended applications: e.g., granite for heavy load-bearing, sandstone for moderate loads, limestone for decorative or light structural work.

Table 2 (Summary from IS 1597 Part 1:1992) - Recommended Use of Common Stones

Additional Specifications:

• Mortar Mix: As per Clause 4(c), mortar type must be compatible with stone type.
• Bond Stones: Clause 9.1.2 requires bond stones to tie masonry units for stability.
• Planning Info: Detailed layout, dimensions, stone class, bond type, and finishes must be provided (Clause 4).

Summary Diagram of Stone Selection Process:

flowchart TD
    A[Determine Usage & Exposure] --> B[Select Suitable Stone Type]
    B --> C[Check Load-Bearing & Durability]
    C --> D[Refer Table 2 IS 1597 Part 1]
    D --> E[Choose Mortar Mix & Bond Type]
    E --> F[Prepare Detailed Design & Layout]

Note: Always cross-check with IS 1597 (Part 1):1992 for detailed tables and definitions.

Design Considerations in IS 1597 Part 2 (Ashlar Masonry)

Key References for Structural Stability (Clause 7.6.1)

• IS 1905:1987 – Code of Practice for Structural Use of Unreinforced Masonry
• IS 1893:1984 – Criteria for Earthquake Resistant Design of Structures
• IS 4326:1976 – Code of Practice for Earthquake Resistant Design and Construction of Buildings

Materials (Clause 5.1)

• Use materials as per IS 1597 (Part 1):1992, Clause 5.
• Stone selection based on Table 2 of IS 1597 (Part 1):1992 (e.g., granite, sandstone, limestone) depending on exposure and load conditions.

General Design Guidelines

• Structural stability must consider load combinations, lateral forces (wind, seismic), and foundation interaction.
• Follow IS 1905 for allowable stresses and design methods for masonry walls.
• Use IS 1893 for seismic load calculations.
• Apply IS 2:1960 for rounding off numerical values to maintain precision.

Fixing of Frames (Clause 8.8)

• Refer IS 1597 (Part 1):1992, Clause 8.8 for detailed fixing methods of door/window frames to masonry.

Typical Formula for Masonry Design (from IS 1905)

Allowable compressive stress, ( f_m ):

[ f_m = \frac{f_{m,0}}{\gamma_m} ]

Where:

• ( f_{m,0} ) = characteristic compressive strength of masonry
• ( \gamma_m ) = partial safety factor (usually 2.5)

Simplified Load Combination (IS 1893)

Design Load, ( W_d ) = 1.5D + 1.5L + 1.0E

flowchart LR
    A[Selection of Stone] --> B[Material Properties]
    B --> C[Structural

General Requirements for Masonry Construction (IS 1597 Part 2)

Key References

• Structural stability & strength: Refer IS 1905:1987, IS 1893:1984, IS 4326:1976
• Stone masonry definitions: IS 1597 (Part 1):1992

Information to be Provided (Clause 4)

• Layout plan with structure orientation
• Dimensioned details: foundation levels, floor heights, openings, sections (scale 1:20)
• Material details: stone type, masonry class, bond types, mortar mix, finishes
• Service embedments: openings, chases, hearths, flues, chimneys

Material & Selection (Clause 5 & 6)

• Use materials as per IS 1597 (Part 1):1992, Clause 5
• Stone selection based on use-case; see Table 2 of IS 1597 (Part 1):1992

Typical Structural Stability Checks (from IS 1905 & IS 4326)

• Compressive strength of masonry:
  [ f_m = f_b \times \text{mortar strength factor} ]
• Allowable stresses depend on stone type and mortar grade.
• Seismic considerations per IS 1893 and IS 4326 for lateral stability.

Summary Table: Masonry Design Inputs

flowchart TD
    A[Start: Project Planning] --> B[Provide Layout & Dimensions]
    B --> C[Select Stone & Mortar]
    C --> D[Design for Structural Stability]
    D --> E[Detail Openings & Embedments]
    E --> F[Execute Masonry Construction]

For detailed formulas and tables, refer to IS 1597 Part 1 & IS 1905.

IS 1597 Part 2: Ashlar Masonry & Dressing Key Points

Types of Ashlar Masonry (Clause 9.1 & 9.7)

• Plain Ashlar (9.1): Stones are finely dressed with flat, smooth faces and square edges for tight joints.
• Ashlar for Special Works (9.7): Stones dressed similarly but shaped for curved, radial, or circular joints.

Dressing Specifications (Clause 9.5.1 & 9.1.1)

• Face Dressing:
  • Fine chisel draft 2 to 5 cm wide around edges.
  • Rough tooling between drafts.
  • Surface deviation ≤ 3 mm from straight edge.
• Joint Dressing:
  • Joints must be truly vertical, horizontal, radial, or circular as per structural needs.
  • Faces dressed to uniform curves or planes for special shapes.

Summary Table:

flowchart LR
    A[Stone Block] --> B[Chisel Draft 2-5 cm]
    B --> C[Rough Tooling inside Draft]
    C --> D[Surface deviation ≤ 3 mm]
    D --> E{Joint Type}
    E --> F[Vertical/Horizontal (Plain Ashlar)]
    E --> G[Radial/Circular (Special Ashlar)]

This ensures tight, durable joints and aesthetically uniform stone masonry.

IS 1597 Part 2 — Structural and Functional Characteristics Summary

1. Structural Stability and Strength (Clause 7.6.1)

• Design should ensure stability and strength against loads.
• Refer to:
  • IS 1905:1987 — Code for masonry structures.
  • IS 1893:1984 — Criteria for earthquake-resistant design.
  • IS 4326:1976 — Earthquake-resistant design guidelines.

2. General Masonry Requirements (Clause 6.8)

• For damp-proof course (DPC):
  • Use materials and locations as per Clause 6.8 of IS 2212:1991.
  • DPC prevents moisture rising through masonry.

3. Fixing of Frames (Clause 8.8)

• Follow Clause 8.8 of IS 1597 Part 1:1992 for:
  • Proper fixing methods of door/window frames.
  • Ensures structural integrity and functional performance.

Key References Table

Typical Structural Strength Check Formula (from IS 1905)

[ \sigma = \frac{P}{A} \leq f_m ]

• (\sigma): Stress on masonry
• (P): Applied load
• (A): Cross-sectional area
• (f_m): Permissible masonry stress (from IS 1905 tables)

flowchart TD
    A[Structural Design] --> B[Check Stability & Strength]
    B --> C[Refer IS 1905, IS 1893, IS 4326]
    A --> D[Damp-proof Course]
    D --> E[Refer IS 2212 Clause 6.8]
   

IS 1597 Part 2: Damp-Proof Course (DPC) Key Points

1. Function & Location (Ref: IS 2212:1991, Clause 6.8)

• DPC prevents moisture rising through walls by capillary action.
• Provided at plinth level, below floor slabs, and at junctions prone to dampness.
• Materials: Impervious materials like bitumen felt, polyethylene sheets, slate, stone, or special bricks.

2. Materials & Thickness (from IS 2212:1991)

3. Stone DPC (IS 1597 Part 2 specific)

• Stone blocks for DPC shall be cut, grooved, rebated, sunk or moulded (Clause 7.1.2).
• Use stones of uniform height per course.
• Exposed faces should be properly finished to ensure bonding and durability.

4. Typical Section for Stone DPC

graph LR
A[Wall] --> B[Damp Proof Course]
B --> C[Stone Blocks]
C --> D[Grooved / Rebated / Moulded Surface]

Summary:

• Use impervious materials per IS 2212.
• Stone DPC blocks must be uniform height, properly finished (Clause 7.1.2).
• Thickness and material depend on site conditions and IS 2212 specs.

For detailed design, always refer to IS 2212:1991 along with IS 1597 Part 2.

Mortar Types as per IS 1597 (Part 2) & IS 1597 (Part 1):

• Clause 7.4 refers to IS 1597 (Part 1) for mortar types. Typically, mortar types are classified based on cement, lime, and sand proportions.
• Common mortar types (from IS 1597 Part 1, Clause 7.4):

Jointing and Pointing (Clause 8.10):

• All joints must be fully filled with mortar.
• Maximum joint thickness:
  • 3 mm for general masonry.
  • 6 mm for block-in-course masonry.
• Pointing should be done with the same mortar as bedding if done during construction.
• If raking out joints after hardening, use specially prepared mortars.
• Various pointing types illustrated in IS 2212:1991 Fig. 10.

Summary Table for Mortar Mix Ratios (from IS 1597 Part 1:1992)

flowchart TD
    A[Stone Masonry] --> B[Mortar Types]
    B --> C[M1: 1:0:3]
    B --> D[M2: 1:1:6]
    B --> E[M3: 1:2:9]
    A --> F[Jointing & Pointing]
    F --> G[Full joints with mortar]
    F --> H[Max joint thickness 3mm (6

IS 1597 (Part 2) - Jointing and Pointing Key Points

• Mortar Filling:
  All joints must be fully filled with mortar; avoid mere pointing.

• Pointing Practice:

  • Should be done as work proceeds using the same mortar as bedding.
  • If done later by raking out, use specially prepared mortars.

• Joint Thickness:

  • Maximum 3 mm for normal joints.
  • Up to 6 mm allowed for block-in-course masonry.

• Joint Preparation for New-Old Work Interface:

  • Rake back joints at a max angle of 30° to horizontal to prevent cracks (Clause 8.7.5).

• Bonding:

  • Stones must break joint on the face for at least half the course height (Clause 8.7.4).

• Pointing Types:
  Refer to Fig. 10 of IS 2212:1991 for types such as flush, recessed, weathered, etc.

Summary Table: Joint Thickness Limits

Visual Concept (Mermaid.js):

flowchart TD
    A[Stone/Block] -->|Break joint ≥ 50% height| B[Maintain Bond]
    B --> C[Full Mortar Joint]
    C --> D{Pointing Needed?}
    D -- No --> E[Finish Work]
    D -- Yes --> F[Pointing with Bedding Mortar]
    F --> G{After Hardening?}
    G -- Yes --> H[Use Special Mortar]
    G -- No --> I[Proceed with Pointing]
    E & H & I --> J[Joint Thickness ≤ 3 mm (6 mm for block-in-course)]

References:

• IS 1597 (Part 2): 1992, Clauses 8.10, 8.7.4, 8.7.5
• IS 2212:1991 Fig.10 for pointing types.

Handling and Lifting of Stones (IS 1597 Part 2:1992)

Key Points from Clauses:

• Clause 8.4:

  • Prefer lifting stones by grips at the top rather than ends.
  • Allows precise setting before releasing tackle.
  • Protect finished surfaces and edges from damage during handling.

• Reference:

  • Various lifting methods are illustrated in Fig. 10, IS 1597 Part 1:1992 (e.g., sling, clamps, grips).

General Recommendations:

• Use lifting grips/hooks embedded or attached at the stone top.
• Avoid lifting from ends to prevent damage or slippage.
• Protect exposed surfaces with padding or wooden blocks during lifting.

Typical Handling Calculations:

• Safe lifting load (W) depends on stone weight and tackle capacity.

• Stone weight ( W = V \times \rho )
  Where:

  • ( V ) = volume of stone (m³)
  • ( \rho ) = density of stone (~2600 kg/m³ for granite)

• Ensure tackle capacity > 1.5 × stone weight (factor of safety).

Example Table (from IS 1597 Part 1:1992 - Table 2):

flowchart LR
    A[Stone to be lifted] --> B{Lifting Method}
    B --> C[Grip at Top (Preferred)]
    B --> D[Slings/Clamps at Ends (Avoid if possible)]
    C --> E[Set stone in position before releasing]
    D --> F[Risk of damage to edges]

Summary: Use top grips for lifting stones, protect surfaces, calculate weight using volume × density, and refer IS 1597 Part 1 Fig. 10 for detailed lifting methods.

IS 1597 Part 2: Scaffolding Key Points

1. Types of Scaffolding:

• Double scaffolding (two sets of vertical supports) is mandatory per IS 2750:1964 for masonry work.

2. Fixing of Frames:

• Refer to Clause 8.8 of IS 1597 Part 1:1992 for detailed frame fixing methods ensuring stability and load transfer.

3. Structural Stability & Strength:

• Design considerations must comply with:
  • IS 1905:1987 (Masonry Design)
  • IS 1893:1984 (Earthquake Resistant Design)
  • IS 4326:1976 (Earthquake Resistant Structures)

4. Storey Rods:

• Use storey rods to mark door/window heights and other critical dimensions during masonry construction (Clause 8.7.9).

Typical Scaffolding Load Formula (from IS 2750):

[ W = W_d + W_l + W_s ]

Where:

• (W_d) = Dead load of scaffold components
• (W_l) = Live load (workers, materials) (typically 2 kN/m²)
• (W_s) = Wind load (as per IS 875 Part 3)

Summary Table: Scaffolding Loads (IS 2750)

flowchart LR
    A[Scaffolding] --> B[Double Scaffolding (IS 2750)]
    A --> C[Frame Fixing (IS 1597 Pt 1)]
    A --> D[Load Considerations]
    D --> E[Dead Load]
    D --> F[Live Load]
    D --> G[Wind Load]
    A --> H[Storey Rods for Dimensions]

Note: Always cross-check scaffold design with site-specific loads and safety factors as per relevant IS codes.