Code of practice for roofing with wooden shingles

IS 2700: Scope - Key Points & Specifications

Clause 3.1: Essential Information for Planning & Execution

• Surface area to be covered
• Type & arrangement restrictions of supporting elements
• Slope and drainage provisions
• Fixing details for ridge pieces
• Timber species and grading
• Moisture content of timber
• Details of pre-treatment

Moisture Content & Timber Treatment

Timber for Battens & Rafters (Clause 4.3)

• Must conform to IS: 3629-1986 for structural timber
• Preservative treatment as per IS: 401-1982

Units & Symbols (SI Units)

Summary Diagram: Planning Inputs for Timber Work

graph TD
    A[Planning & Execution] --> B[Surface Area]
    A --> C[Supporting Elements]
    A --> D[Slope & Drainage]
    A --> E[Ridge Fixing]
    A --> F[Timber Species & Grading]
    A --> G[Moisture Content]
    A --> H[Pre-treatment Details]

References:

• IS 287-1973 (Timber seasoning)
• IS 401-1982 (Timber preservation)
• IS 3629-1986 (Structural timber requirements)

IS 2700 - Definitions & Key Specifications Summary

• Reference Standards:

  • Definitions mainly as per IS 707-1961.
  • Timber moisture content as per IS 287-1973.
  • Timber preservation per IS 401-1982.

• Key Definitions:

  • Valley: The re-entrant angle formed by the intersection of two inclined roof surfaces (Clause 2.16).

• Moisture Content:

  • Timber must be seasoned to moisture content limits defined in IS 287.
  • Moisture content affects timber strength and durability.

• Timber Treatment:

  • Wooden shingles should be preservative-treated following IS 401.

• Essential Information for Work Planning (Clause 3.1):

  • Surface area to cover.
  • Type and arrangement of supports.
  • Drainage slope provisions.
  • Fixing details for ridge pieces.
  • Timber species and grading.
  • Moisture content.
  • Pre-treatment details.

• SI Units Used:

flowchart TD
    A[Timber Definitions IS 2700] --> B[Moisture Content IS 287]
    A --> C[Preservation IS 401]
    A --> D[Key Terms (Valley)]
    A --> E[Planning Info Clause 3.1]
    E --> F[Surface Area]
    E --> G[Support Types]
    E --> H[Drainage Slope]
    E --> I[Ridge Fixing]
    E --> J[Species & Grading]
    E --> K[Moisture Content]
    E --> L[Pre-treatment]

This summary ensures compliance with IS 2700 and related standards for timber roofing and structural use.

IS 2700: Necessary Information for Planning and Execution

Key Information (Clause 3.1)

For efficient planning and execution, the following must be known:

• Surface area to be covered.
• Type of supporting elements and any restrictions on their arrangement.
• Slope and drainage requirements.
• Provision for fixing ridge pieces.
• Species and grading of timber used.
• Moisture content of timber (refer IS:287-1973 for seasoning).
• Details of pre-treatment (preservative treatment per IS:401-1982).

Timber Specifications

• Timber must conform to IS:3629-1986 for battens and rafters.
• Preservative treatment as per IS:401-1982.
• Moisture content limits as per IS:287-1973 (generally seasoned timber).

Moisture Content Table (Typical Limits from IS:287-1973)

Definitions

• Valley (Clause 2.16): Re-entrant angle formed by intersection of two inclined roof surfaces.

Summary Diagram of Planning Inputs

graph TD
    A[Planning & Execution] --> B[Surface Area]
    A --> C[Supporting Elements]
    A --> D[Slope & Drainage]
    A --> E[Ridge Fixing]
    A --> F[Timber Species & Grading]
    A --> G[Moisture Content]
    A --> H[Pre-treatment Details]

Use these parameters for design, procurement, and quality control to ensure durability and structural integrity.

IS 2700: Materials and Specifications - Key Points

Moisture Content (Clause 3.1)

• Timber must be seasoned to moisture content as per IS 287-1973.
• Maximum permissible moisture content varies by timber use (refer IS 287).

Timber Treatment

• Wooden shingles must be preservative-treated as per IS 401-1982.
• Structural timber for battens and rafters to follow IS 3629-1986 and preservative treatment per IS 401-1982.

Design & Planning Data (Clause 3.1)

• Surface area to cover
• Type & arrangement of supports
• Slope and drainage provisions
• Ridge fixing details
• Timber species & grading
• Moisture content
• Pre-treatment details

Units & Definitions (SI Units)

Summary Table: Timber Moisture Content (Indicative)

flowchart TD
    A[Planning] --> B[Surface Area]
    A --> C[Support Elements]
    A --> D[Slope & Drainage]
    A --> E[Ridge Fixing]
    A --> F[Timber Species & Grading]
    A --> G[Moisture Content]
    A --> H[Pre-treatment]

    F --> I[IS 3629-1986]
    G --> J[IS 287-1973]
    H --> K[IS 401-1982]

References: IS 287-1973, IS 401-1982, IS 3629-1986 for timber specifications and treatments.

IS 2700 - Design Considerations Summary

Key Design Considerations (Clause 3.1)

• Surface area to be covered.
• Type & arrangement of supporting elements.
• Slope & drainage provisions.
• Fixing details for ridge pieces.
• Timber species & grading.
• Moisture content of timber (see Table A-3).
• Pre-treatment details (preservative treatment per IS:401-1982).

Timber Specifications

• Timber for battens and rafters must conform to IS:3629-1986.
• Timber must be preservative treated as per IS:401-1982.
• Use seasoned timber with moisture content per IS:287-1973 (typically 12-15% for structural use).

Moisture Content Table (Excerpt from Table A-3)

Units and Symbols (SI Units)

• Length: m
• Force: N (1 N = 1 kg·m/s²)
• Stress/Pressure: Pa (1 Pa = 1 N/m²)

Practical Notes:

• Ensure timber is graded and treated to prevent decay.
• Provide adequate slope for drainage on roofs.
• Confirm fixing and support details for structural stability.

flowchart TD
    A[Design Considerations] --> B[Surface Area]
    A --> C[Support Type & Arrangement]
    A --> D[Slope & Drainage]
    A --> E[Fixing Ridge Pieces]
    A --> F[Timber Species & Grading]
    A --> G[Moisture Content]
    A --> H[Pre-treatment Details]

This ensures compliance with IS 2700 for timber roofing design.

IS 2700: Key Specifications & Formulas for Laying Wooden Shingles

• Overlap Requirement (Clause 5.5):

  • Minimum overlap = 1/3 of shingle length (L)
  • Overlapped length = 2L/3
  • Exposed length = L/3

• Shingle Courses:

  • Shingle covering must be at least 3 courses deep at every section.

• Nailing:

  • Use 2 wire nails (40 mm long) per shingle.

• Battens (Typical Sizes):

  • Main batten: 50 × 40 mm
  • Subsidiary batten: 40 × 25 mm

• Typical Section Dimensions (mm):

  Parameter	Dimension
  Overlapped length	2L/3
  Exposed length	L/3
  Batten sizes	50×40 (main), 40×25 (subsidiary)
  Nail length	40 mm

• Ridge Detail:

  • Use a one-piece angular wooden ridge for hip ridges.

Diagram: Shingle Overlap and Batten Arrangement

flowchart LR
    A[Wooden Rafter] --> B(Main Batten 50x40)
    B --> C(Subsidiary Batten 40x25)
    C --> D[Wooden Shingle]
    D --> E[Overlap 2L/3]
    D --> F[Exposed Length L/3]
    D --> G[2 Wire Nails per Shingle]

This ensures durability, water-tightness, and structural integrity per IS 2700 guidelines.

IS 2700: Maintenance Key Points & Specifications

• Moisture Content:
  Timber must be seasoned as per IS:287-1973 to a specified moisture content for durability and performance.

• Preservative Treatment:
  Wooden shingles and structural timber (battens, rafters) must be treated per IS:401-1982 to resist decay and pests.

• Planning Data Required (Clause 3.1):

  • Surface area coverage
  • Supporting elements & restrictions
  • Drainage slope provisions
  • Ridge fixing details
  • Timber species & grading
  • Moisture content
  • Pre-treatment details

• Timber for Structural Use:
  Must comply with IS:3629-1986 and be preservative treated (IS:401-1982).

Typical Moisture Content Limits (from IS:287-1973)

Preservation Treatment (IS:401-1982)

• Pressure impregnation or surface treatment methods
• Use of approved preservatives like creosote, copper-chrome-arsenic (CCA) compounds
• Treatment depth and retention as per timber use and exposure

flowchart TD
    A[Timber Selection] --> B[Seasoning as per IS:287]
    B --> C[Moisture Content Check]
    C --> D[Preservative Treatment (IS:401)]
    D --> E[Installation Planning]
    E --> F[Maintenance & Inspection]

Summary: Proper seasoning, preservative treatment, and adherence to IS codes ensure timber durability and ease of maintenance.

IS 2700 - Timber for Wooden Shingles: Key Specifications & Species

1. Quality Requirements (Clause 1.1 & Appendix A)

• Durability: Use heartwood with high decay resistance, low shrinkage.
• Attributes: Dimensional stability, light weight, good insulation, adequate strength, even grain, and ability to accept stains/paint/preservatives.
• Uniformity: Shingles on one roof must be of the same size.
• Grade: Use Grade 2 timber as per IS 1331-1971 (Standard grade), only heartwood and edge-grained timber.

2. Recommended Timber Species

3. Moisture Content

• Timber must be adequately dried to minimize shrinkage and warping (typically below 15%).

4. Additional Notes

• Shingles can be sawn or split.
• Follow preservation standards as per Code of Practice for Preservation of Timber (3rd revision).

Summary Table: