Method of measurement of building and civil engineering works, Part 5: formwork

IS 1200 Part 5 - Scope Summary for Formwork Measurement

Scope (Clause 1.1):

• Covers the method of measurement of formwork when measured separately in building and civil engineering works.

Key Specifications (Clause 3.1):

Formwork measurement includes:

• Edges, notchings, overlaps, sheathing battens, strutting, bolting, nailing, wedging, easing, striking, removal
• All supports (struts, braces, wedges, mud sills, piles)
• Fasteners like bolts, wire ties, clamps, nails
• Working scaffolds, ladders, gangways
• Filleting for stop-chamfered edges or splayed angles (max 20 mm wide)
• Temporary openings for pouring, vibrating, cleaning
• Dressing with oil to prevent adhesion
• Raking or circular cutting

Measurement Rules (Clause 6.6):

• Formwork to secondary beams measured up to sides of main beams; no deduction at intersections.
• Formwork to beams measured up to sides of columns; no deduction at beam-column intersections.

Summary Table of Included Items

This ensures complete and consistent measurement of formwork including all ancillary components and temporary works as per IS 1200 Part 5.

flowchart TD
    A[Formwork Measurement] --> B[Edges, Notchings, Overlaps]
    A --> C[Supports & Struts]
    A --> D[Fasteners (Bolts, Nails)]
    A --> E[Scaffolds & Ladders]
    A --> F[Filleting ≤ 20 mm]
    A --> G[Temporary Openings]
    A --> H[Dressing with Oil]
    A --> I[Raking & Circular Cutting]

IS 1200 Part 5 - General Rules for Measurement of Formwork

Key Specifications & Rules

• Scope (Clause 1.1): Covers method of measurement of formwork when measured separately.

• Work to be Measured Separately (Clause 2.5):

  • Work in or under water
  • Work in liquid mud
  • Work in or under foul positions
  • Work interrupted by tides

• Formwork Includes (Clause 3.1):

  • Splayed edges, notchings, overlaps, sheathing battens, strutting, bolting, nailing, wedging, easing, striking, removal
  • Supports: struts, braces, wedges, mud sills, piles
  • Fasteners: bolts, wire ties, clamps, spreaders, nails
  • Working scaffolds, ladders, gangways
  • Filleting for stop-chamfered edges or splayed external angles ≤ 20 mm wide
  • Temporary openings for pouring, vibrating, cleaning
  • Dressing with oil to prevent adhesion
  • Raking or circular cutting

• Measurement Rules (Clause 6.6):

  • Formwork for secondary beams measured up to main beam sides; no deduction at intersections
  • Formwork for beams measured up to column sides; no deduction at beam-column intersections

Rounding Off Rules

• Numerical values are to be rounded off as per the revised rules (not detailed here).

Summary Table: Formwork Components Included

flowchart TD
    A[Formwork Measurement] --> B[Include Edges, Notchings, Overlaps]
    A --> C[Include Supports & Fasteners]
    A --> D[Include Scaffolds & Ladders]
    A --> E[Include Filleting ≤ 20mm]
    A

IS 1200 Part 5: Description of Formwork - Key Points

1. Components of Formwork (Clause 3.1)

• Edges & joints: Splayed edges, notchings, overlaps, sheathing battens.
• Supports: Struts, braces, wedges, mud sills, piles.
• Fasteners: Bolts, wire ties, clamps, nails.
• Access: Scaffolds, ladders, gangways.
• Filleting: Stop-chamfered edges or splayed angles ≤ 20 mm wide.
• Temporary openings: For pouring, vibrating, cleaning.
• Surface treatment: Dressing with oil to prevent concrete adhesion.
• Cutting: Raking or circular cutting for shaping.

2. Measurement of Formwork (Clause 6.1 & 2.7)

• Unit: Measured in square metres (m²) of actual surface in contact with concrete.
• Stages: Separate measurement for:
  • Below ground/datum level.
  • Above ground/datum level.
• Note: Ground datum level must be specified.

Summary Table: Formwork Elements & Specifications

flowchart TD
    A[Formwork] --> B[Edges & Joints]
    A --> C[Supports & Bracing]
    A --> D[Fasteners]
    A --> E[Access & Scaffolds]
    A --> F[Filleting & Chamfers]
    A --> G[Temporary Openings]
    A --> H[Surface Treatment]
    A --> I[Measurement in m²]

This concise framework ensures formwork is safe, functional, and measurable per IS 1200 Part 5 guidelines.

Classification of Formwork (IS 1200 Part 5)

Key Clauses:

• Clause 3.1: Formwork includes sheathing, supports, fasteners, scaffolds, filleting, openings, dressing with oil, and cutting.

• Clause 4.1: Types of formwork by contact surface:

  • a) Wrought (planed/sawn timber)
  • b) Tongued & grooved boards
  • c) Plywood lining
  • d) Special lining for smooth/decorative finish
  • e) Steel sheeting/tubing
  • f) Slip form technique (extrusion process)

• Clause 5.1: Classification by formwork location/type for measurement:

Summary Table of Formwork Types by Contact Surface

IS 1200 Part 5: Measurement Units and Booking of Dimensions

Key Specifications:

• Booking Sequence (Clause 2.2):
  Dimensions must be booked consistently in the order:
  Length → Breadth/Width → Height/Depth/Thickness

• Measurement Precision (Clause 2.4.1):
  All dimensions are measured to the nearest 0.01 m (1 cm).

• Scope (Clause 1.1):
  Applies specifically to the measurement of formwork when measured separately.

General Guidelines:

• Measurement is critical from initial estimates to final payment.
• Uniformity in measurement methods is encouraged to avoid ambiguity.
• Measurement systems should align with administrative and financial frameworks but maintain technical consistency.

Summary Table for Booking Dimensions

flowchart LR
    A[Length] --> B[Breadth/Width]
    B --> C[Height/Depth/Thickness]

This ensures clarity and uniformity in recording dimensions for civil engineering works, especially formwork.

IS 1200 Part 5: Method of Measurement for Formwork

Key Points:

• Scope: Covers measurement of formwork when measured separately.
• Purpose: Ensures uniformity and clarity in measurement for planning, execution, and payment.
• Importance: Standardizes measurement to avoid ambiguities among agencies.

General Specifications:

• Measurement should include surface area of formwork in contact with concrete.
• Includes all faces of formwork, including soffits, sides, and ends.
• Deductions for openings like door/window reveals are generally made.
• Measurement is usually in square meters (m²).

Typical Measurement Formula:

[ \text{Formwork area} = \sum (\text{length} \times \text{height or width of each face}) ]

Measurement Rules:

• Include all edges and returns.
• Include formwork for columns, beams, slabs, walls separately.
• Thickness of formwork is not measured, only surface area.
• Allow for laps and joints as per site conditions.

Example Table: Formwork Measurement Units

flowchart LR
    A[Start: Identify Formwork Element] --> B[Measure Length & Height]
    B --> C[Calculate Surface Area (L × H)]
    C --> D{Multiple Faces?}
    D -- Yes --> E[Sum all faces]
    D -- No --> F[Use single face area]
    E --> G[Subtract openings if applicable]
    F --> G
    G --> H[Record measurement in m²]
    H --> I[Use for cost estimation/payment]

This method ensures clarity and uniformity in formwork measurement as per IS 1200 Part 5.

IS 1200 Part 5: Measurement in Stages (Formwork)

Key Points from Clause 2.7:

• Work is measured in convenient stages based on height or depth:
  • Below ground/datum level
  • Above ground/datum level
• The ground datum level must always be specified.

Measurement Guidelines:

• Dimensions must be recorded to the nearest 0.01 m (Clause 2.4.1).
• Separate measurement for formwork is covered (Clause 1.1).
• Staged measurement helps track progress and payment accurately.

Typical Measurement Table Format (Example):

Summary:

• Always specify the datum level.
• Measure work below and above datum separately.
• Use nearest 0.01 m for dimensions.
• Staged measurement ensures clarity in progress and payments.

flowchart TD
    A[Start Measurement] --> B{Is work below or above datum?}
    B -->|Below| C[Measure depth, record stage]
    B -->|Above| D[Measure height, record stage]
    C --> E[Specify datum level]
    D --> E
    E --> F[Record dimensions to 0.01 m]
    F --> G[Calculate quantities per stage]
    G --> H[Use for progress/payment]

This approach aligns with IS 1200 Part 5 for clear, standardized measurement in civil works.

IS 1200 Part 5 - Bills of Quantities & Formwork Measurement

Key Points from IS 1200 Part 5 (1982):

• Bills of Quantities must:
  • Fully describe materials and workmanship.
  • Accurately represent the work to be executed (Clause 2.6).

Formwork Classification & Measurement (Clause 5.1):

General Measurement Rules:

• Surface areas are generally measured in square meters (m²).

IS 1200 Part 5 - Rounding Off and Final Values

• Rounding Off Rule (Clause 0.5):
  Final measured or calculated values must be rounded off per IS 2:1960 (Rules for rounding off numerical values).

  • Retain the same number of significant places as the specified value in the standard.
  • Example: If a dimension is specified as 2.50 m, round off your measurement to 2 decimal places.

• Measurement Precision (Clause 2.4.2):

  • Areas should be calculated and recorded to the nearest 0.01 m².

• Work Measured Separately (Clause 2.5):
  Work under special conditions must be measured separately:

  • In or under water
  • In liquid mud
  • In foul positions
  • Interrupted by tides

Summary Table for Rounding (as per IS 2:1960)

Example:

If specified value = 12.30 m, measured = 12.345 m → rounded value = 12.30 m (2 decimal places).

flowchart TD
    A[Measured/Calculated Value] --> B{Compare with Specified Value's decimals}
    B -- Equal decimals --> C[Round off according to IS 2:1960]
    B -- More decimals --> D[Truncate to specified decimals]
    C --> E[Final Rounded Value]
    D --> E

This ensures consistency and compliance in measurements and reporting.

IS 1200 Part 5 — Special Cases & Additional Instructions for Formwork Measurement

Key Specifications:

• Formwork includes:
  • Splayed edges, overlaps, notches, sheathing battens, strutting, bolting, nailing, wedging, easing, striking, removal.
  • All supports (struts, braces, wedges, mud sills, piles).
  • Bolts, wire ties, clamps, nails, spreaders.
  • Working scaffolds, ladders, gangways.
  • Filleting for stop-chamfered edges or splayed external angles ≤ 20 mm wide.
  • Temporary openings for pouring, vibrating, cleaning.
  • Dressing with oil to prevent adhesion.
  • Raking or circular cutting.

Measurement Rules (Clause 6.6):

• Formwork for secondary beams measured up to main beam sides; no deduction at intersections.
• Formwork for beams measured up to column sides; no deduction at beam-column intersections.

Special Conditions (Clause 2.5):

• Measure work separately if executed:
  • In/under water
  • In liquid mud
  • In foul positions
  • Interrupted by tides

Measurement Formula (Conceptual):

[ \text{Formwork Area} = \sum (\text{Surface area of formwork including allowances}) ]

• Include all edges, openings, supports as per above.
• No deductions at intersections.

Summary Table for Formwork Measurement:

flowchart TD
    A[Formwork Components] --> B[Splayed edges, overlaps]
    A --> C[Supports, struts, braces]
    A --> D[Bolts, wire ties, nails]
    A --> E[Temporary openings]
    A --> F[Filleting ≤ 20 mm]
    B & C & D & E & F --> G[Measurement Area]
    G --> H[Include