Safety code for demolition of buildings

IS 4130: Scope & Key Specifications Summary

• Scope: IS 4130 covers guidelines for demolition of structures, including safety and procedural aspects.

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

• Material Handling:
  Clause 12.7 prohibits dumping or storing materials on catch platforms during demolition.

• Mechanical Demolition (Clause 13):

  • Barricade area: 12 × height of wall radius.
  • No personnel inside demolition zone during operation.
  • Position mechanical devices to avoid debris fall on people or property.
  • Prevent damage to adjacent structures, power lines, etc.

• Reference Standard:
  IS 4130:1991 (Reaffirmed 2002) is the main standard; related standards should be consulted as adjuncts.

Example: Barricade Distance Calculation

If wall height = 5 m, barricade radius = 12 × 5 = 60 m

flowchart LR
    A[Wall Height (h)] --> B[Calculate Barricade Distance]
    B --> C[Distance = 12 × h]
    C --> D[Set Barricade Radius]

This ensures safety during mechanical demolition per IS 4130.

Pre-demolition Study and Planning (IS 4130 Key Points)

Clause 3.1: Structural Study & Planning

• Conduct a detailed study of the building and surroundings.
• Understand load paths and support systems for all parts.
• Prepare a stage-wise demolition plan approved by the engineer-in-charge.
• Brief workers on safety measures before each demolition stage.

Clause 6.6: Demolition Sequence

• Demolish storey-by-storey from top down.
• Complete upper floors before disturbing lower supports.
• Sectional demolition allowed if safety is ensured.

Clause 12.7: Material Handling

• No dumping or storage of materials on catch platforms.

Clause 13: Mechanical Demolition Precautions

• Barricade area: 12 × wall height radius.
• No workers inside during mechanical operation.
• Position equipment to avoid debris fall on people/structures.
• Prevent damage to adjacent structures, power lines.

Clause 14.6.2.1: Hard Demolition of RC Elements

Summary Diagram of Demolition Sequence (Top-down)

flowchart TD
    A[Start Demolition] --> B[Study Structure & Load Paths]
    B --> C[Prepare & Approve Demolition Plan]
    C --> D[Demolish Top Storey]
    D --> E{Upper Floor Complete?}
    E -- Yes --> F[Demolish Next Lower Storey]
    E -- No --> D
    F --> G[Repeat Until Ground Floor]
    G --> H[Complete Demolition]

Key Safety Distance:

• Barricade radius = 12 × wall height

Note: Always ensure controlled cutting and lowering of RC elements to avoid sudden collapse or hazards.

IS 4130 Key Points on Safety Precautions & Electrical Services

Safety Precautions (Clause 15.13)

• Keep portable first-aid fire appliances ready where fire risk exists.
• Appliances must comply with IS 2190 : 1979 (portable fire extinguishers).
• Follow BIS guidelines for quality, inspection, and continuous monitoring.

Electrical Services (Clause 4.6)

• Power shut-off: All electrical lines must be disconnected at or outside the property line before demolition.
• Obtain prior approval from electrical authorities before cutting lines.
• Exception: Power lines needed for demolition work can remain live.

Mechanical Demolition Safety (Clause 13)

• Barricade area: minimum distance = 12 × wall height.
• No workers inside the building during mechanical demolition.
• Position equipment to avoid falling debris hazards.
• Prevent damage to adjacent structures and power lines.

Quick Reference Table: Barricade Distance

Summary Diagram of Safety Zones

graph TD
  A[Wall] -->|12 × height| B[Barricade]
  B --> C[Safe Zone]
  subgraph Danger Zone
    A
  end

Always coordinate with electrical authorities and ensure compliance with BIS standards for fire safety and electrical disconnection before demolition.

IS 4130: Protection of Public and Adjacent Properties - Key Points

Key Specifications:

• Nail Removal (Clause 4.11):
  All nails in removed lumber must be withdrawn, hammered, or bent over immediately to prevent injury or damage.

• Protection of Fixtures (Clause 6.2):
  Existing fixtures needed during demolition must be protected with substantial covering or temporarily relocated as per regulations.

• Public Protection (Clause 5.10):

  • Worker entrances without sidewalk sheds must have canopies extending ≥ 2.5 m from the building face.
  • Canopy width ≥ building entrance width + 0.6 m on each side.
  • Canopy strength must equal sidewalk sheds (refer Clause 5.5 for sidewalk shed specs).

• Utilities Protection (Clause 4.8):
  All mains and meters must be removed or adequately protected to avoid damage.

Typical Sidewalk Shed Strength (from 5.5, summarized):

• Designed to withstand minimum live load of 5 kN/m².
• Must be stable against wind and impact loads.

Summary Table:

flowchart TD
    A[Demolition Start] --> B[Nail Removal]
    B --> C[Fixture Protection]
    C --> D[Public Protection]
    D --> E[Canopy Installation]
    E --> F[Utilities Protection]
    F --> G[Demolition Proceed]

This ensures safety of public, workers, and adjacent properties during demolition per IS 4130.

Sequence of Demolition Operations (IS 4130)

• Systematic Storey-by-Storey Demolition (Clause 6.6):

  • Demolish from top floor downwards.
  • Complete upper floor demolition before disturbing lower floor supports.
  • Sectional demolition allowed if safety ensured.

• Hard Demolition Procedures (Clause 14.6.2.1):

  • Beams:
    1. Attach supporting rope.
    2. Remove concrete at ends to expose reinforcement.
    3. Cut reinforcement to lower beam safely.
  • Columns:
    1. Place restraining wire guy ropes at top.
    2. Expose reinforcement at base.
    3. Cut reinforcement to pull column down under control.
  • Walls:
    • Cut into strips and demolish like columns.

• Arch Demolition Sequence (Clause 14.4.2.1):

  1. Remove spandrel down to springing line.
  2. Remove arch rings.
  3. Remove abutments.

• Precautions (Clause 14.7.2):

  • Prevent toppling of prefabricated units.
  • Provide temporary supports as needed.

flowchart TD
    A[Start Demolition] --> B[Remove Spandrel to Springing Line]
    B --> C[Remove Arch Rings]
    C --> D[Remove Abutments]
    D --> E[Demolish Upper Floors Storey-by-Storey]
    E --> F[Demolish Beams (Attach Rope, Cut Reinforcement)]
    E --> G[Demolish Columns (Guy Ropes, Cut Reinforcement)]
    E --> H[Demolish Walls (Cut into Strips)]
    F & G & H --> I[Provide Temporary Supports if Needed]
    I --> J[Complete Demolition]

Key Notes:

• Safety and control are paramount—use ropes and guy wires.
• Follow sequence strictly to avoid structural instability.

IS 4130 Key Points on Debris Removal & Material Handling

• Hole Area for Debris Drop (Clause 7.3.1):
  Maximum hole area in any intermediate floor ≤ 25% of that floor's area.
  Ensure the storage floor below can withstand impact loads.

• Catch Platforms (Clause 12.7):

  • No dumping of materials on catch platforms.
  • Catch platforms are not for storage.

• Mechanical Demolition Safety (Clause 13):

  • Barricade radius ≥ 12 × height of wall.
  • No workers inside during operation.
  • Position equipment to avoid debris fall on people/structures.
  • Avoid damage to adjacent structures and utilities.

Summary Table: Debris Drop Hole Area

flowchart TD
    A[Demolition Floor] -->|Debris drop through hole ≤ 25% area| B[Storage Floor]
    B -->|Must withstand impact| C[Debris Collection]
    D[Mechanical Device] -->|Operate within barricaded zone| E[Safe Zone]
    E -->|No workers inside| F[Demolition Site]

Note: Always verify storage floor strength and barricade distances as per site-specific conditions.

IS 4130: Use of Ladders, Stairs, and Passageways – Key Points

1. Ladders (Ref: IS 3696 Part 2:1991)

• Follow IS 3696 (Part 2) for ladder design, construction, and safe use.
• Key specs:
  • Ladder angle: ~75° to horizontal.
  • Minimum rung spacing: 250 mm.
  • Rung diameter: 25-40 mm.
  • Load capacity: As per IS 3696 guidelines.

2. Stairs and Passageways (Clause 4.10)

• Provide safe, clear walkways and passageways for workers.
• Must be:
  • Adequately illuminated
  • Free from debris and obstructions
• Workers must be instructed in their use.

3. Material Handling (Clause 7.4.5)

• Debris or malba must not be used without inspection.
• Only serviceable materials approved by a competent person can be reused.

Summary Table: Ladder Dimensions (IS 3696 Part 2)

flowchart TD
    A[Start] --> B[Provide ladders as per IS 3696]
    B --> C[Ensure stairs & passageways are clear and lit]
    C --> D[Inspect materials before reuse]
    D --> E[Safe access ensured for workers]

Always refer to IS 3696 (Part 2) for detailed ladder safety and dimensions.

IS 4130: Key Points on Demolition of Walls

1. Demolition Procedures for Reinforced Concrete Walls (Clause 14.6.2.1c)

• Cut walls into strips (approx. 230 mm wide).
• Demolish strips similarly to columns: expose reinforcement, cut, and pull down under control.
• Use temporary centering if necessary.

2. Safety & Stability (Clause 9.9)

• Foundation/retaining walls must not be demolished until:
  • Adjoining structures are underpinned or braced.
  • Earth is removed by sheet piling or sheathing.

3. Mechanical Demolition Precautions (Clause 13)

• Barricade area: minimum distance = 12 × wall height.
• No workers inside the building during operation.
• Position equipment to avoid debris falling on people or structures.
• Avoid damage to adjacent structures or utilities.

Summary Table: Demolition Steps for RC Walls

flowchart TD
    A[Start Demolition] --> B[Cut Wall into 230 mm Strips]
    B --> C[Expose Reinforcement]
    C --> D[Cut Reinforcement]
    D --> E[Pull Down Strips Under Control]
    E --> F[Temporary Centering if Required]
    F --> G[Complete Demolition]

Note: Always follow safety guidelines for ladders (Clause 8.5) and avoid dumping materials on catch platforms (Clause 12.7).

IS 4130 Key Points on Floor Removal and Load Management

• Shoring & Support (Clause 7.3.4):

  • If cutting holes in intermediate floors weakens them, provide proper shoring.
  • Ensure supporting walls have adequate lateral restraints to prevent instability.

• Demolition Sequence (Clause 6.6):

  • Demolition must proceed storey by storey, top-down.
  • Complete work on upper floors before disturbing supports below.
  • Sectional demolition allowed only with safety measures.

• Safety Clearances (Clause 10.5):

  • Clear floor and surrounding area 6.0 m radius of personnel and debris before starting demolition.

• Material Handling (Clause 11.3):

  • Use tag lines on all materials being lowered or hoisted.
  • Employ a standard signal system for communication.
  • Use independent working platforms where possible.
  • Limit strip widths to 300 mm max during floor removal.

Typical Shoring & Load Management Diagram (Fig. 2 Concept)

flowchart TB
    A[Cutting Hole in Floor] --> B{Is Floor Unsafe?}
    B -- Yes --> C[Provide Shoring]
    C --> D[Check Lateral Restraints on Walls]
    B -- No --> E[Proceed with Demolition]
    D --> E

Summary Table: Key Specifications

This ensures structural safety and worker protection during floor removal.

Key Specifications & Practices for Use of Derricks and Structural Steel Handling (IS 4130)

1. Derrick Support (Clause 11.1):

• The supporting floor must be strong enough to carry the derrick load.
• Use heavy planking to distribute load evenly over floor beams and girders.

2. Handling Structural Steel (Clause 11.6):

• Steel members must be lowered carefully; dropping is prohibited to avoid damage.

3. Safety Measures (Clause 11.3):

• Use tag lines on all materials during lifting/lowering.
• Employ a standard signal system with trained workmen for communication.

4. Catch Platforms (Clause 12.7):

• Materials should not be dumped or stored on catch platforms to prevent overload and hazards.

Additional Practical Guidelines (Engineering Knowledge)

Load Distribution Concept

flowchart TD
    Load[Load from Derrick] --> Planking[Heavy Planking]
    Planking --> FloorBeam[Floor Beams]
    FloorBeam --> Girders[Girders]
    Girders --> Structure[Building Structure]

Summary: Ensure strong floor support with planking, avoid dropping steel members, use tag lines and signals, and keep catch platforms clear. Follow safety distances during mechanical demolition.

IS 4130: Catch Platforms for Safety — Key Specifications

• Width: Minimum 1.5 m horizontally from the face of the structure (Clause 12.3).
• Construction:
  • Made of outriggers and planks laid tightly without gaps.
  • Planks can be wood or other materials of equal strength (Clause 12.4).
• Parapet: Continuous solid parapet along outer edge, minimum 1 m height, same material/specification as platform (Clause 12.3).
• Load Capacity: Must sustain a live load of 6100 N/m² (Clause 12.5).
• Handling: Steel members must be lowered, not dropped, onto platforms (Clause 11.6).

Load Design Formula for Catch Platform

[ \text{Design Load} = 6100 , \text{N/m}^2 \quad (\text{minimum live load}) ]

Ensure platform structural members and connections are designed for this uniform load plus self-weight.

Summary Table

graph LR
A[Face of Structure] -->|1.5 m| B[Catch Platform]
B --> C[Parapet (≥1 m height)]
B --> D[Outriggers + Planks (tight)]
D --> E[Supports 6100 N/m² live load]

IS 4130: Mechanical Demolition Key Points & Procedures

Safety Precautions (Clause 13)

• Barricade radius: Minimum 12 × wall height around demolition site.
• No personnel inside building during mechanical operation.
• Equipment must be positioned to avoid falling debris.
• Ensure no damage to adjacent structures or utilities (power lines, etc.).

Hard Demolition Procedures (Clause 14.6.2.1)

Demolition Sequence (Clause 6.6)

• Demolish storey-by-storey, top-down.
• Complete upper floor demolition before disturbing supports below.
• Sectional demolition allowed if injury and damage prevention measures are in place.

Diagram: Controlled Beam Lowering (Simplified)

flowchart LR
    A[Attach Supporting Rope] --> B[Remove Concrete Ends]
    B --> C[Expose Reinforcement]
    C --> D[Cut Reinforcement]
    D --> E[Lower Beam Under Control]

For detailed visuals, see Fig. 5 in IS 4130. Always follow systematic, controlled demolition to ensure safety and structural integrity.

IS 4130: Demolition of Special Structural Elements — Key Points

1. Demolition Procedures (Clause 14.6.2.1)

• Reinforced Concrete Beams:

  • Attach supporting rope securely.
  • Remove concrete at both ends using pneumatic drill.
  • Expose and cut reinforcement to lower beam under control.

• Reinforced Concrete Columns:

  • Place restraining wire guy ropes at top.
  • Expose reinforcement at base.
  • Cut reinforcement to pull column down safely.

• Reinforced Concrete Walls:

  • Cut into strips (~230 mm wide).
  • Demolish strips like columns.

2. Mechanical Demolition Precautions (Clause 13)

• Barricade area: 12 × wall height radius.
• No workers inside during operation.
• Position equipment to avoid falling debris.
• Prevent damage to adjacent structures and utilities.

3. Special Elements (Clause 14.7.1 & 14.8)

• Study joints/supports of precast units before demolition.
• For prestressed concrete, consult expert engineer before demolition.

Summary Diagram (Hand Demolition Sequence)

flowchart LR
    A[Attach Supporting Rope] --> B[Remove Concrete Ends]
    B --> C[Expose Reinforcement]
    C --> D[Cut Reinforcement]
    D --> E[Lower Beam/Column Under Control]

Note:

• Do not dump materials on catch platforms (Clause 12.7).
• Always ensure controlled and safe lowering/pulling to avoid sudden collapse.

IS 4130: Miscellaneous Safety Measures (Clause 15.13 & related)

Key Safety Requirements:

• Fire Safety:
  Portable first-aid fire appliances must be available where fire risk exists, per IS 2190:1979 (Portable Fire Extinguishers).

• Mechanical Demolition Safety (Clause 13):

  • Barricade area: 12 × height of wall radius.
  • No workers inside demolition zone during operation.
  • Equipment positioned to avoid falling debris on personnel or adjacent structures.
  • Prevent damage to nearby structures and utilities.

• Material Handling (Clause 12.7):
  No dumping or storage on catch platforms.

• Personal Protective Equipment (Clause 15.4):
  Use safety helmets conforming to IS 2925:1984 where falling objects risk exists.

Relevant Standards Summary

Visual: Mechanical Demolition Safety Zone

graph TD
    A[Wall Height H]
    B[Safety Barricade Radius = 12 × H]
    C[Mechanical Device]
    D[No Workmen Zone]
    A --> B
    B --> D
    C --> D

Summary: Ensure fire extinguishers per IS 2190 are accessible, barricade demolition zones 12 times wall height, prohibit workers inside during demolition, avoid debris hazards, and mandate IS 2925 helmets for falling material risks.