Methods of building and civil engineering works, Part 28: Sound insulation works

IS 1200 Part 28: Scope - Key Points & Specifications

• Scope: Covers measurement methods for civil engineering works excluding river valley projects (ref: CED 44).
• Measurement Rules:
  • Final measured/calculated values must be rounded per IS 2:1960 rules, retaining the same significant figures as specified.
  • Curved, conical, and spherical works must be described separately with their radius (Clause 7.2).
  • Sound insulation works above 10 m height are measured in 5 m stages if no floor exists; otherwise, per storey (Clause 7.4).

Rounding Off (IS 2:1960)

• Retain the same number of significant digits as the specified value.
• Round off the last digit based on the next digit (≥5 rounds up).

Measurement Table Extract (Clause 7.4)

Summary Diagram (Measurement Scope)

flowchart TD
    A[Civil Engineering Works] --> B[Exclude River Valley Projects]
    B --> C[Measurement as per IS 1200 Pt 28]
    C --> D[Curved/Conical/Spherical Work]
    C --> E[Sound Insulation Work]
    E --> F{Height > 10 m?}
    F -- Yes --> G[Measure in 5 m stages]
    F -- No --> H[Measure per storey]

Note: Always verify using the latest edition and amendments from BIS.

IS 1200 Part 28: General Rules for Measurement of Sound Insulation

Key Points:

• Scope: Measurement applies to sound insulation in buildings and civil engineering works (Clause 1.1).

• Isolated Widths: Sound insulation in isolated widths such as bands, corners, window cills, door/window jambs, sunk panels, and rounded angles must be measured separately (Clause 5.8).

• Rounding Off:

  • Final measured/calculated values should be rounded as per IS 2:1960 rules.
  • Retain the same number of significant figures as the specified value in the standard (Clause 6).

• Curved Surfaces: Curved, conical, and spherical surfaces must be described separately with the radius specified (Clause 7.2).

Summary Table:

Note on Rounding (IS 2:1960):

• If the digit to be dropped is >5, round up.
• If <5, round down.
• If =5, round to nearest even number.

flowchart LR
    A[Start Measurement] --> B{Isolated Width?}
    B -- Yes --> C[Measure Separately]
    B -- No --> D[Measure Normally]
    D --> E{Curved Surface?}
    C --> E
    E -- Yes --> F[Describe with Radius]
    E -- No --> G[Record Measurement]
    F --> G
    G --> H[Round Off per IS 2:1960]
    H --> I[Final Value]

This ensures clarity and uniformity in sound insulation measurement as per IS 1200 Part 28.

IS 1200 Part 28: Bill of Quantities - Key Points

• Clubbing of Items (Clause 2.1): Items in the Bill of Quantities (BoQ) may be clubbed together for simplification.

• Specifications for Sound Insulation (Clause 4.1):
  Each classification of sound insulation work should be measured separately with details including:

  • Material specification
  • Number & thickness of coats
  • Surface treatment
  • Base nature
  • Special shapes (curved, conical, elliptical) with radius

• Measurement Importance:
  Measurement is critical from initial estimates to final settlement. IS 1200 promotes unification of measurement methods to avoid ambiguity across agencies.

Typical BoQ Structure (Summary)

General Measurement Formula

[ \text{Quantity} = \text{Length} \times \text{Breadth} \times \text{Height/Thickness} ]

For curved/special shapes, apply geometric formulas or radius-based calculations as specified.

flowchart TD
    A[Start: Project Scope] --> B[Identify Items for BoQ]
    B --> C{Club Items?}
    C -->|Yes| D[Combine Items]
    C -->|No| E[Separate Items]
    D --> F[Specify Details (Material, Coats, Surface)]
    E --> F
    F --> G[Measure Quantities]
    G --> H[Prepare BoQ]
    H --> I[Use for Tendering & Payment]

Summary: IS 1200 Part 28 guides systematic measurement and item classification for BoQ, emphasizing clarity and uniformity to aid contractors and departments.

IS 1200 Part 28: Sound Insulation Treatment - Key Points

1. Work Description (Clause 3.1)

• Materials and workmanship must be fully described.
• Work to be executed must be accurately represented.

2. Sound Insulation Treatment (Clause 4.1)

For each sound insulation work, specify:

3. Measurement (Clause 5)

• Measure each classification of sound insulation separately.
• Measurement includes thickness and area coverage.

Additional Engineering Notes:

• Sound Transmission Loss (STL) depends on material density, thickness, and frequency.
• Common formula for mass law of sound insulation:

[ STL = 20 \log (m \times f) - 47 ]

Where:

• ( STL ) = Sound Transmission Loss (dB)
• ( m ) = mass per unit area (kg/m²)
• ( f ) = frequency (Hz)

flowchart TD
    A[Start: Define Sound Insulation Work] --> B[Specify Material]
    B --> C[Specify Number & Thickness of Coats]
    C --> D[Specify Surface Treatment]
    D --> E[Specify Base Type]
    E --> F[Specify Special Shapes & Radius]
    F --> G[Measurement of Each Classification]
    G --> H[Execution & Quality Check]

Summary: IS 1200 Part 28 emphasizes thorough specification of materials, coats, surface, base, and shape details for sound insulation, with separate measurement for each classification.

IS 1200 Part 28: Method of Measurement - Key Points

• Measurement Units:

  • Linear dimensions measured to nearest 0.01 m (if ≤ 25 m).
  • For dimensions > 25 m, measured to nearest 0.1 m.
  • Areas calculated to nearest 0.01 m².

• Measurement Principles:

  • Measurements are net (actual work done, excluding overlaps).
  • Measurements fixed in position as per site conditions.
  • Separate measurement for special works like sound insulation on ceilings, walls, floors.

• Purpose:

  • Standardize measurement across agencies.
  • Avoid ambiguity in quantities.
  • Facilitate clear financial and technical assessment.

Typical Measurement Formulae

Measurement Flow (Simplified)

flowchart TD
    A[Start Measurement] --> B[Identify Work Item]
    B --> C[Measure Dimensions (to nearest 0.01/0.1 m)]
    C --> D[Calculate Area/Volume]
    D --> E[Record Net Quantity]
    E --> F[Separate Special Works (e.g., Sound Insulation)]
    F --> G[Finalize Measurement]

Note: Refer to IS 1200 Part 28 for detailed clauses on specific items and measurement nuances.

IS 1200 Part 28: General Rules for Measurement (Sound Insulation Work)

Key Points:

• Rounding Off Values:
  Follow IS 2:1960 for rounding off numerical values.

  • Retain the same number of significant places as specified in the standard.

• Measurement Specifics (Clause 5.8):

  • Measure sound insulation in isolated widths separately, e.g.,
    • Bands
    • Corners
    • Window cills
    • Door and window jambs
    • Sunk panels
    • Rounded angles

• Scope (Clause 1.1):

  • Applies to sound insulation in buildings and civil engineering works.

General Measurement Principles:

• Measure length, breadth, and thickness of the insulation materials accurately.
• For isolated or irregular sections, measure each part separately to avoid errors.
• Use standard units (meters, square meters) consistently.

Summary Table: Measurement of Sound Insulation Components

flowchart LR
    A[Start Measurement] --> B{Component Type?}
    B -->|Flat Surface| C[Measure Length & Breadth]
    B -->|Isolated Widths| D[Measure Linear Width Separately]
    B -->|Rounded Angles| E[Measure Curved Surface Area]
    C --> F[Calculate Area (m²)]
    D --> F
    E --> F
    F --> G[Apply IS 2:1960 Rounding]
    G --> H[Record Final Value]

Use IS 1200 Part 28 in conjunction with IS 2:1960 for precise, standardized measurement and rounding rules.

IS 1200 Part 28: Detailed Method of Measurement – Key Points

• Measurement Units:

  • Linear dimensions measured to 0.01 m accuracy.
  • For lengths > 25 m, measure to 0.1 m accuracy.
  • Areas calculated to 0.01 m² accuracy.

• General Principles:

  • Measurements are net, i.e., only the actual work fixed in position.
  • Uniform decimal system is used for clarity and consistency.
  • Separate measurement for specialized works like sound insulation on ceilings, walls, and floors.

• Purpose:

  • Standardizes measurement methods across agencies.
  • Facilitates clear communication, reduces disputes.
  • Supports accurate cost estimation and project management.

Measurement Accuracy Summary

flowchart TD
    A[Start Measurement] --> B{Dimension Length?}
    B -->|≤ 25 m| C[Measure to 0.01 m]
    B -->|> 25 m| D[Measure to 0.1 m]
    C & D --> E{Calculate Area?}
    E -->|Yes| F[Calculate to 0.01 m²]
    E -->|No| G[Record Linear Measurement]
    F & G --> H[Net Measurement Fixed in Place]
    H --> I[Use for Estimation & Billing]

For detailed item-wise measurement, refer to IS 1200 Parts relevant to specific works.