Preservative-treated and seasoned sawn timber from rubber wood (Hevea Brasiliensis)
2001 Edition

Overview of Scope (IS 14960)

1. Dimensional Tolerances (Clause 5.2.2)

Permitted size deviations for timber grades:

• Note: Negative width tolerance permissible for up to 10% of supply at a time.

2. Preservation Criteria (Clause 4.1)

Treatment as per IS 401 with retention and penetration requirements per IS 2753 (Part 1):

3. Rounding Off Procedures

• Follow IS 2:1960 for rounding test outcomes.
• Maintain significant figures consistent with standard values.

Diagrammatic Summary:

flowchart TD
    Grade[Timber Grade] --> Tolerance{Tolerance Limits}
    Tolerance -->|+3 mm / -1 mm| Grades[A, B, C]
    Grade --> Preservation[Preservative Treatment]
    Preservation --> Hazard{Hazard Class}
    Hazard -->|H1| H1Details[DSR=5.0, Full Penetration]
    Hazard -->|H2| H2Details[DSR=8.0, Full Penetration]

Key References in IS 14960 (Annex A)

1. Referenced Codes

• IS 14960 integrates provisions from multiple Indian Standards listed in Annex A.
• It is important to consult the latest editions of these referenced codes.
• Rounding of numerical data follows IS 2:1960.

2. Dimensional Tolerances (Clause 5.2.2)

• Negative width tolerance allowed in no more than 10% of supplied timber.

3. Preservation Requirements (Clause 4.1)

¹ Boron retention applies selectively

² Copper/Zinc retention varies with chemical type

4. Defect Limits (Clause 6)

• Defect measurement follows IS 3364 (Part 2).
• Limits vary by grade (see Table 1 in IS 14960).

Summary

• Use IS 2:1960 for rounding.
• Size tolerances are +3 mm and -1 mm with restrictions on negative width.
• Preservation levels depend on hazard classification with specified chemical retentions.

Key Terms and Definitions per IS 14960 (Clause 3.1)

1. Use IS 707 for standard timber-related terminology.
2. Additional definitions specific to preservative-treated rubber wood apply.

Dimensional Tolerances (Clause 5.2.2)

• Negative width tolerance permitted for up to 10% of supply.

Preservation Parameters (Clause 4.1)

Treatment as per IS 401 with retention and penetration per IS 2753 (Part 1):

Rounding Off (General)

• Adhere to IS 2:1960 for numerical rounding, retaining significant figures.

Preservation Guidelines in IS 14960 (Clauses 4.1 & 4.2)

• Preservative Treatment: Timber must be treated following IS 401 using approved chemicals.

• Dry Salt Retention (DSR) & Penetration: As specified in IS 2753 (Part 1), retention and penetration depend on exposure hazard class:

• Seasoning: Treated timber should be seasoned as per IS 1141; moisture content and residual stresses must meet specified criteria.

¹ Boron compounds

² Copper/Zinc-based preservatives

Process Flow:

flowchart LR
    Timber[Timber] --> Treatment[Preservative Treatment (IS 401)]
    Treatment --> Testing[Measure DSR & Penetration (IS 2753)]
    Testing --> HazardClass{Hazard Class}
    HazardClass -->|H1| H1Details[DSR=5.0 kg/m³; Full Penetration]
    HazardClass -->|H2| H2Details[DSR=8.0 kg/m³; Full Penetration]
    HazardClass -->|H3| H3Details[DSR=12.0 kg/m³; Full Penetration]
    HazardClass -->|H4| H4Details[DSR=16.0 kg/m³; Full Penetration]

Summary of Dimensions and Tolerances (IS 14960)

1. Dimensional Agreement

• Dimensions must be mutually agreed upon by manufacturer and purchaser (Clause 5.1).

2. Size Tolerances (Clause 5.2.2)

• Negative width tolerance is permitted for a maximum of 10% of the batch.

3. Allowed Defects (Clause 6)

• See Table 1 in IS 14960 for defect limits per grade.
• Defects are measured per IS 3364 (Part 2).
• Timber must be sawn straight and trimmed square, free from prohibited defects (Clause 4.3).

4. Rounding of Results

• Follow IS 2:1960 for rounding test values, preserving significant digits.

Quick Reference for Tolerances

| Grade | + Tolerance (mm) | - Tolerance (mm) |
|-------|------------------|------------------|
| A     | +3               | -1               |
| B     | +3               | -1               |
| C     | +3               | -1               |

This ensures adherence to dimensional accuracy and product quality.

Permissible Defects under IS 14960

1. Defect Limits (Clause 6 & Table 1)

• Timber is categorized into Grades A, B, and C with associated defect allowances.
• Defects measured as per IS 3364 (Part 2).
• Common defects include knots, splits, insect damage, decay, and pitch pockets.
• Only defects specified as permissible for each grade are acceptable.

2. Size Tolerances (Clause 5.2.2)

• Negative width tolerance must not exceed 10% of total supply.

3. Quality Standards (Clause 4.3)

• Timber should be free from unauthorized defects.
• Must be straight sawn, square trimmed, and treated per IS 401.

Process Diagram

flowchart TD
    Timber --> GradeCheck{Grade A, B, or C}
    GradeCheck --> SizeCheck[Verify Size Tolerance]
    SizeCheck -->|Within +3/-1 mm| Accept[Accept]
    SizeCheck -->|Outside Tolerance| Reject[Reject or Reprocess]
    GradeCheck --> DefectCheck[Check Permitted Defects]
    DefectCheck -->|Within Limits| Accept
    DefectCheck -->|Exceeds Limits| Reject

This framework guarantees timber quality meets required durability and strength.

Marking and Certification Essentials (IS 14960)

1. BIS Certification Mark (Clauses 7.2 & 7.2.1)

• Each product bundle must bear the BIS Standard Mark to confirm conformity.
• This marking ensures traceability and compliance with the standard.

2. Size Tolerances (Clause 5.2.2)

• Negative width tolerance should not exceed 10% of supply.

3. Defect Control (Clause 6)

• Defects are limited per grade as detailed in Table 1 and measured by IS 3364 Part 2.

4. Rounding Off

• Test results must be rounded according to IS 2:1960, preserving the precision of significant digits.

Overview Diagram

flowchart TD
    Bundle[Product Bundle] --> MarkingCheck{Is Marked?}
    MarkingCheck -->|Yes| BISMark[BIS Standard Mark]
    BISMark --> SizeToleranceCheck[Check Size Tolerances]
    SizeToleranceCheck --> GradeEval{Grade A/B/C}
    GradeEval --> Tolerance[+3 mm / -1 mm]
    GradeEval --> WidthTolerance[Negative width ≤ 10%]
    SizeToleranceCheck --> DefectCheck[Assess Permissible Defects]
    DefectCheck --> Measurement[Measured per IS 3364 Part 2]
    Measurement --> Rounding[Rounding as per IS 2:1960]

This guarantees product quality, traceability, and adherence to IS 14960.

IS 14960 references multiple Indian Standards essential for design and construction. Annex A contains the complete list; key ones include:

• IS 456:2000 – Code for Plain and Reinforced Concrete
• IS 875 (Parts 1-5) – Design Loads (Dead, Live, Wind, Earthquake, Snow)
• IS 800:2007 – Steel Construction Code
• IS 1904:1986 – Foundation Engineering
• IS 13920:2016 – Ductile Detailing for RC Structures under Seismic Loading

Important Notes:

• Always verify you are consulting the most recent edition.
• These standards provide design principles, material specs, and safety factors.
• For example, the flexural design formula from IS 456 is: [ M_u \leq 0.87 f_y A_s (d - \frac{a}{2}) ] where (M_u) is ultimate moment, (f_y) yield strength, (A_s) steel area, (d) effective depth, and (a) depth of equivalent stress block.

Summary Table of Important IS Codes:

Refer to Annex A of IS 14960 for the complete and updated list.

Committee Members for IS 14960 (Annex B)

The committee responsible for establishing IS 14960 is detailed in Annex B, under the Timber and Timber Stores Sectional Committee, CED 9.

Highlights:

• Chairperson: Shri Shyam Sunder (Individual Capacity, Bangalore)
• Members: Representatives from industry, research institutions, government forest departments, and timber-related organizations, including:
  • Andaman Chamber of Commerce
  • Central Building Research Institute
  • Forest Research Institute
  • Directorate General of Civil Aviation
  • Directorate of Naval Architecture
  • Directorate General of Supplies and Disposal
  • Bamboo Society of India
  • Multiple state forest departments
  • Indian Plywood Industries Research and Training Institute

Purpose:

• This multidisciplinary group ensures comprehensive development of the standard covering technical, industrial, and regulatory aspects.

Sample Table of Committee Composition

For detailed member information and roles, consult Annex B of IS 14960.