Methods for field testing of preservatives in wood

IS 4833: Scope — Key Points & Specifications

Scope:
IS 4833 covers the durability of untreated and treated timber species against termite attack, ensuring quality through inspection, testing, and quality control under BIS supervision.

Key Specifications:

• Specimen Size & Selection:
  Refer Clause 3.1.1 & 6.1 for detailed dimensions and selection criteria of timber specimens for testing.

• Inspection & Recording of Results:

  • Follow Clause 3.5 and Clause 6.4 for inspection methods and recording.
  • Visual evaluation of termite damage is quantified by Numerical Rating (Clause 5.5):

Additional Notes:

• The Standard Mark ensures compliance with BIS quality control.
• Inspection involves cleaning specimens and visual assessment.
• BIS enforces continuous conformity checks.

flowchart TD
    A[Timber Specimen Selection] --> B[Exposure to Termites]
    B --> C[Specimen Retrieval & Cleaning]
    C --> D[Visual Inspection]
    D --> E[Assign Numerical Rating]
    E --> F[Durability Assessment]

This summarizes the scope and evaluation framework for timber durability per IS 4833.

IS 4833: Key References, Formulas & Tables

Inspection & Recording of Results (Clauses 5.5 & 6.4)

• Clause 5.5: Condition Rating of Termite Attack

• Clause 6.4: Inspection

  • Follow procedures as per Clause 3.5.
  • Use of BIS Standard Mark ensures compliance with IS standards.
  • Continuous quality control and inspection by BIS.

Additional Notes

• BIS Act, 1986 governs the use of Standard Mark.
• Copyright of IS publications is with BIS; reproduction requires permission.
• Contact BIS regional offices for licensing and standards queries.

Summary Diagram: Inspection & Rating Process

flowchart TD
    A[Specimen Dug Out] --> B[Clean Mud & Debris]
    B --> C[Visual Evaluation]
    C --> D{Condition of Sample?}
    D -->|No Attack| E[Rating 0]
    D -->|Trace Attack <5%| F[Rating 0.5]
    D -->|Light Attack 5-20%| G[Rating 1.0]
    D -->|Moderate 20-30%| H[Rating 2.0]
    D -->|Heavy 35-40%| I[Rating 3.0]
    D -->|Very Heavy >50%| J[Rating 4.0]

For detailed procedures, refer to Clauses 3.5, 5.5, and 6.4 of IS 4833.

IS 4833: Field Testing of Preservatives Using Stakes – Key Points

Specimen Dimensions (Clause 3.1)

• Length: 305 mm
• Cross-section: 38.1 mm × 38.1 mm (square)
• Stakes must be free from knots, stains, mold, decay, or defects.

Sampling (Clause 2.5)

• For each species:
  • Test 6 logs (2 logs from each of 3 widely separated areas).
  • Each log: 2–2.5 m length, taken ~1 m above ground.
  • From each log, cut 6 specimens per preservative level (including untreated control).
• Test at 3 preservative absorption levels (including control).
• Include 2 reference species:
  • Chir (Pinus roxburghii) – coniferous
  • Mango (Mangifera indica) – broadleaved
• Reference species help benchmark durability and environmental degradation.

Installation

• Stakes installed in the field as per Clause 3.4 (details in IS 4833).

Reporting

• Round off values per IS 2:1960 rules.

Summary Table: Specimen Preparation

This method ensures uniformity and comparability of preservative efficacy under natural conditions. For detailed installation and test procedures, refer to IS 4833 full text.

IS 4833: Field Testing of Preservatives Using Thin Specimens (Accelerated Test)

Key Points from Clause 5.0 (Accelerated Test)

• Purpose: Quick, comparative evaluation of preservatives against termite attack.
• Specimens: Thin wood samples treated with preservatives.
• Exposure: Placed in termite-prone field conditions for accelerated degradation.
• Inspection Frequency: Similar to stake tests, but accelerated due to thinness.
• Evaluation: Visual observation for termite damage; extent of attack scored.

Scoring System (from Clause 1.5 for reference)

Additional Notes:

• Knife Test: Used to verify decay extent.
• Comparison: Enables rapid screening of preservative effectiveness.
• Reference: IS 401:1982 for preservative details and treatment methods.

Summary Diagram of Accelerated Test Process

flowchart TD
    A[Prepare Thin Specimens] --> B[Treat with Preservatives]
    B --> C[Place in Termite-Prone Field]
    C --> D[Periodic Inspection]
    D --> E{Visual & Knife Test}
    E --> F[Score Damage %]
    F --> G[Evaluate Preservative Performance]

This method helps in quick screening before long-term stake tests.

IS 4833: Field Testing of Preservatives Against Termites

Key Specifications & Procedures

• Specimens: Use stakes or thin wood specimens treated with preservatives.
• Installation: Place specimens in termite-prone field conditions.

Inspection Frequency

Evaluation of Termite Attack (Visual & Knife Test)

• Knife Test: Piercing wood to assess decay extent.
• Reporting: Round off values as per IS 2:1960.

Reference

• IS 401:1982 for preservative types and treatment methods.

flowchart TD
    A[Install Treated Specimens] --> B{Inspection Frequency}
    B -->|Stake Test| C[Quarterly (1st yr), Half-yearly (2nd), Yearly (after)]
    B -->|Thin Specimens| D[Monthly (1st yr), Every 2 months (2nd), Half-yearly (after)]
    C & D --> E[Visual & Knife Test]
    E --> F{Evaluate % Attack}
    F -->|5-10%| G[Slight (1-1.5)]
    F -->|11-25%| H[Moderate (2-3)]
    F -->|26-50%| I[Bad (3-4.5)]
    F -->|>50%| J[Destroyed (5)]

This method provides a comparative, quick assessment of preservative effectiveness against termites in field conditions.

Durability Testing of Timber (IS 4833 Highlights)

• Specimen Preparation (Clause 2.5 & 38.1):

  • Logs: 6 logs/species (2 logs from each of 3 different regions).
  • Length: 2 to 2.5 m logs, cut ~1 m above ground.
  • Specimens: 305 mm long × 38.1 mm square, heartwood from seasoned planks.
  • For each preservative and absorption level, 6 specimens per test yard.
  • Include 2 reference species: Chir (Pinus roxburghii) & Mango (Mangifera indica).

• Treatment Levels:

  • Three absorption levels including one untreated control.

• Installation:

  • Specimens installed as stakes (Clause 3.4).

• Inspection & Rating (Clause 5.5):

• Evaluation:
  • After exposure, specimens cleaned and visually inspected for deterioration and termite damage.
  • Ratings help compare durability among species and treatment levels.

This procedure ensures standardized durability assessment of untreated and treated timbers under natural conditions.

IS 4833: Size and Selection of Specimens

Key Clauses Summary:

• Clause 3.1.1 / 4.1 / 5.2 / 6.1 collectively guide specimen size and selection to ensure representativeness and accuracy in testing.

Size of Specimens (Typical Guidelines):

• Minimum Size: Specimens should be large enough to represent the material's properties accurately.
• Dimensions:
  • For concrete or aggregate specimens, usually 150 mm diameter × 300 mm height for cylinders.
  • For other materials, dimensions depend on the test type but must avoid edge effects.

Selection of Specimens:

• Random Sampling: Specimens must be selected randomly from the batch to avoid bias.
• Number of Specimens: Usually, a minimum of 3 specimens per test for statistical reliability.
• Condition: Specimens should be free from defects and represent the average quality of the material.

Typical Table for Specimen Size (Example):

Formula for Volume of Cylindrical Specimen:

[ V = \pi \times \left(\frac{d}{2}\right)^2 \times h ]

Where:

• ( d ) = diameter (mm)
• ( h ) = height (mm)

flowchart TD
    A[Material Batch] --> B[Random Sampling]
    B --> C[Specimen Selection]
    C --> D[Size Check]
    D --> E{Meets IS 4833 Size?}
    E -- Yes --> F[Testing]
    E -- No --> G[Resample or Resize]

Note: Always refer to the latest IS 4833 edition for precise dimensions and selection criteria per material type and test.

IS 4833: Replication and Installation of Specimens – Key Points

Replication Requirements (Clauses 3.4 & 5.4)

• Replicates per species/absorption level: 6 treated specimens + 3 (or 6) untreated controls.
• Arrangement:
  • Test yard: Specimens buried half their length below ground, in horizontal & vertical rows, spaced 600 mm apart.
  • Termite mound tests: Specimens tied in chains with wire, buried at 6 different mound locations.

Specimen Size (Clauses 4.1 & 6.1)

• Exact size not detailed here, refer to IS 4833 Clause 4.1 & 6.1 for standard dimensions (typically uniform blocks for consistency).

Installation Conditions

• Subterranean termite areas: Select highly termite-prone zones for burial.
• Climate considerations:
  • Extreme climates: Test duration May–November (6 months).
  • High rainfall: Test duration 3 months in early summer; maintain termite activity by sprinkling water.

Summary Table for Specimen Installation

flowchart LR
    A[Specimen Preparation] --> B[6 Treated + Controls]
    B --> C{Test Location}
    C -->|Test Yard| D[Buried half-length, 600 mm apart]
    C -->|Termite Mound| E[Chained specimens buried at 6 locations]
    D & E --> F[Monitor for 3-6 months based on climate]

This ensures uniform testing for termite resistance per IS 4833 standards.

IS 4833: Inspection and Recording of Results

Key Points from Clauses 3.5, 4.2, 5.5 & 6.4

• Inspection Procedure (Clauses 3.5 & 4.2):
  Inspection and recording must follow a consistent method as detailed in Clause 3.5, ensuring uniformity in data collection and evaluation.

• Recording Results (Clause 5.5):
  After the test duration, specimens are cleaned and visually assessed for termite attack. The condition is rated numerically as follows:

• Use of Standard Mark (Clause 6.4):
  Products inspected and tested under BIS supervision may carry the Standard Mark, ensuring compliance with IS 4833 and quality control.

Summary Table for Inspection Ratings

| Termite Attack Level     | Surface Area Affected (%) | Rating |
|-------------------------|---------------------------|--------|
| No attack               | 0                         | 0      |
| Trace attack            | < 5                       | 0.5    |
| Light attack            | 5 – 20                    | 1.0    |
| Moderate attack         | 20 – 30                   | 2.0    |
| Heavy attack            | 35 – 40                   | 3.0    |
| Very heavy attack       | > 50                      | 4.0    |

Practical Tip:

• Always record the numerical rating alongside visual observations for clear, standardized reporting.
• Maintain proper documentation as per BIS licensing and quality control requirements.

flowchart TD
    A[Specimen Excavation] --> B[Cleaning of Mud/Debris]
    B --> C[Visual Inspection]
    C --> D{Termite Attack?}
    D -->|No| E[Rating = 0]
    D -->

IS 4833 - Treatment Levels and Absorption (per IS 401:1982)

Key Specifications:

• Treatment Method: As per IS 401:1982.
• Absorption Levels: Six levels overall; three levels per preservative.
• Tolerance: ±2.5% of target absorption.

Absorption Levels for Creosote-Fuel Oil (50:50):

Treatment Details:

• Specimens treated to specific absorption levels.
• Six replicates per species and absorption level.
• Three untreated control specimens.
• Specimens buried half-length below ground, spaced 600 mm apart in horizontal/vertical rows.

Summary:

• Absorption control ensures uniform preservative uptake.
• Treatment levels critical for durability testing and performance evaluation.

flowchart LR
    A[Specimens] --> B[Treatment as per IS 401:1982]
    B --> C{Preservative Type}
    C --> D[Creosote-Fuel Oil 50:50]
    C --> E[Copper-Chrome-Arsenic]
    D --> F[Absorption Levels: 160, 80, 48 kg/m³]
    E --> G[3 Absorption Levels (per IS 401)]
    F & G --> H[Specimens buried half-length underground]
    H --> I[Spacing: 600 mm apart]
    I --> J[Durability Testing]

This ensures standardized treatment and absorption for reliable durability assessment.

IS 4833: Site Selection & Specimen Installation Summary

1. Site Selection (Clause 3.3)

• Number of sites: Preferably 6 sites.
• Location: Different climatic and topographical conditions.
• Purpose: To capture variability in environmental exposure.

2. Specimen Size & Selection (Clauses 3.1.1 & 6.1)

• Specimens must conform to specified sizes (refer to Clause 6.1 for exact dimensions).
• Selection should represent the species and treatment conditions.

3. Replications & Installation (Clause 3.4)

• Replicates: 6 treated specimens + 3 untreated controls per test yard.
• Installation:
  • Specimens buried half their length below ground.
  • Arranged in horizontal and vertical rows.
  • Rows spaced 600 mm apart.

Installation Layout (Mermaid Diagram)

graph TD
    A[Test Yard] --> B[Horizontal Rows]
    A --> C[Vertical Rows]
    B --> D[Specimens buried half-length]
    C --> D
    D --> E[Rows spaced 600 mm apart]
    E --> F[6 treated + 3 control specimens per yard]

This ensures standardized exposure for durability testing across diverse environments. For exact specimen sizes, refer to Clause 6.1 in IS 4833.

IS 4833: Rating of Termite Attack — Key Details

Numerical Rating Table (Clause 5.5)

Durability Rating (Clause 1.5)

Field Testing (Clause 5.0 & 5.4)

• Specimens: 6 replicates at each absorption level + 6 untreated controls.
• Installation: Specimens chained and buried in termite mounds or termite-prone soil.
• Duration: 3-6 months depending on climate and termite activity.
• Inspection: Visual + knife test for decay evaluation.

Summary:

• Visual inspection quantifies termite damage as % surface area attacked.
• Assign numerical rating based on % damage.
• Field tests use chained specimens buried in termite habitats for accelerated results.
• Regular inspections schedule: quarterly (1st year), half-yearly (2nd year), yearly (later).

flowchart TD
    A[Start: Specimen Preparation] --> B[Chain Specimens]
    B --> C{Select Termite-Prone Site}
    C --> D[Bury Specimens in Mound/Soil]
    D --> E[Duration: 3-

IS 4833: Reporting and Documentation - Key Points

Inspection and Recording of Results (Clauses 3.5, 4.2, 5.5, 6.4)

• Inspection must follow the same procedure as in Clause 3.5.
• Results should be recorded systematically for clarity and traceability.
• Use numerical rating for termite attack assessment (Clause 5.5):

Documentation Specifications

• Maintain clear records of inspection dates, specimen conditions, and ratings.
• Reports should comply with BIS guidelines and include:
  • Test conditions
  • Observations
  • Numerical ratings
  • Any deviations or anomalies

Standard Mark & Quality Assurance

• Use of BIS Standard Mark confirms compliance with IS 4833.
• Continuous checking by BIS ensures conformity.
• Licensing details available from BIS offices.

flowchart TD
    A[Specimen Preparation] --> B[Inspection as per Clause 3.5]
    B --> C[Visual Evaluation]
    C --> D[Assign Numerical Rating (Clause 5.5)]
    D --> E[Record Results]
    E --> F[Report Compilation]
    F --> G[Submit for Quality Certification (BIS)]

Summary: Follow Clause 3.5 for inspection, use the termite attack rating table (Clause 5.5), maintain detailed records, and ensure compliance with BIS marking and licensing for documentation.

IS 4833: Safety and Compliance - Key Points

Inspection and Recording (Clauses 3.5 & 6.4)

• Inspection and recording must follow the procedure in Clause 3.5 (detailed inspection methods).
• Records of inspection results should be maintained systematically.
• Continuous quality control and testing are mandatory.

Use of Standard Mark

• Governed by BIS Act, 1986.
• Standard Mark ensures compliance with IS 4833 under BIS-supervised quality control.
• Licenses for use of the Standard Mark are granted by BIS under strict conditions.
• BIS conducts periodic checks on Standard Marked products.

Compliance Summary:

Contact for BIS Licensing & Queries

• Headquarters: Manak Bhavan, 9 Bahadur Shah Zafar Marg, New Delhi 110002
• Regional offices available across India for assistance.

flowchart TD
    A[Manufacturing Process] --> B[Inspection as per Clause 3.5]
    B --> C[Recording of Results]
    C --> D{Quality Control}
    D -->|Pass| E[Standard Mark Licensing by BIS]
    D -->|Fail| F[Re-inspection/Corrective Action]
    E --> G[Continuous BIS Surveillance]

This ensures product safety, conformity, and compliance with IS 4833.

Key Formulas, Tables, and Specifications from IS 4833 (Annexures & Tables)

1. Inspection and Recording of Results (Clause 5.5)

The condition of termite attack on timber samples is rated numerically as:

2. Specimen Replication and Installation (Clause 5.4)

• Replicates: 6 replicates for each absorption level + 6 untreated controls.
• Installation: Samples tied in chains and buried in termite mounds or termite-prone areas.
• Test Duration: 3-6 months depending on climate and termite activity.

3. Inspection Procedure (Clause 6.4)

• Follow inspection and recording as per Clause 3.5.
• Ensure continuous quality control under BIS supervision for Standard Mark products.

Summary Diagram: Termite Attack Rating Process

flowchart TD
    A[Sample Collection] --> B[Clean & Prepare Samples]
    B --> C[Burial in Termite Mounds]
    C --> D[Exposure Period (3-6 months)]
    D --> E[Retrieve Samples]
    E --> F[Visual Inspection]
    F --> G{Assess Termite Damage}
    G -->|No attack| H[Rating 0]
    G -->|Trace attack <5%| I[Rating 0.5]
    G -->|Light 5-20%| J[Rating 1.0]
    G -->|Moderate 20-30%| K[Rating 2.0]
    G -->|Heavy 35-40%| L[Rating 3.0]
    G -->|Very heavy >50%| M[Rating 4.0]

Note: For detailed test methods and quality control, refer to the full IS 4833:1993 standard document.