Non-coniferous sawn timber (Baulks and scantlings)

IS 1326: Scope, Key Specifications, and Measurement

Scope (Clause 2.1)

• IS 1326 covers timber specifications referencing related standards:
  • IS 401:1982 – Preparation of timber
  • IS 707:1976 – Glossary of timber terms (definitions per this standard)
  • IS 1141:1973 – Seasoning of timber
  • IS 1150:1976 – Trade names, symbols, and measurement methods for timber species
• Timber species covered are listed in Annex A & B.
• Nomenclature and abbreviations follow IS 1150:1976.

Dimensions and Measurement (Clause 5.2 & 6.2)

• Volume (m³) = Length × Width × Thickness
• Volume must be accurate to three decimal places.
• Measurements are based on accepted standard sizes.

Summary Table for Volume Calculation

flowchart TD
    A[Timber Piece] --> B[Measure Length (m)]
    A --> C[Measure Width (m)]
    A --> D[Measure Thickness (m)]
    B & C & D --> E[Calculate Volume = L × W × T]
    E --> F[Volume in m³ (3 decimal places)]

This ensures uniformity in timber measurement and grading as per IS 1326.

IS 1326: References & Key Specifications

• Related Indian Standards:

  • IS 401:1982 – Preparation of timber (3rd revision)
  • IS 707:1976 – Glossary of timber terms (2nd revision) (Definitions for IS 1326)
  • IS 1141:1973 – Seasoning of timber (1st revision)
  • IS 1150:1976 – Trade names & abbreviations for timber species (2nd revision)
  • IS 1326:1992 – Current code for timber dimensions and measurements

• Timber Species:

  • Listed in Annex A & B of IS 1326
  • Species nomenclature follows IS 1150:1976

• Key Usage:

  • Use IS 707:1976 for timber-related definitions.
  • Dimensions and measurement methods conform to IS 1326:1992.

Typical Timber Dimensioning (from IS 1326)

Note: Actual sizes are less due to seasoning and planning.

flowchart TD
    A[IS 1326: Timber Code] --> B[IS 707: Definitions]
    A --> C[IS 1150: Species Nomenclature]
    A --> D[IS 401: Preparation]
    A --> E[IS 1141: Seasoning]
    B --> F[Glossary]
    C --> G[Species List Annex A & B]

Summary: IS 1326 references several IS codes for timber preparation, seasoning, and species classification. Definitions and species abbreviations are standardized by IS 707 and IS 1150 respectively. Dimensions follow IS 1326:1992 guidelines.

IS 1326: Definitions & Key Specifications

• Definitions: As per IS 707:1976 (Glossary of Timber Terms), all timber-related terminology in IS 1326 follows this standard.

• Timber Species: Listed in Annex A & B of IS 1326; nomenclature and abbreviations per IS 1150:1976.

Key Formulas and Measurement

• Volume Calculation (Clause 5.2.3):
  [ \text{Volume (m}^3) = \text{Length (m)} \times \text{Width (m)} \times \text{Thickness (m)} ]
  • Volume must be accurate to 3 decimal places.
  • Measurements are based on accepted sizes.

Related Standards (Clause 2.1)

flowchart TD
    A[IS 1326 Definitions] --> B[IS 707:1976 Terms]
    A --> C[Timber Species - Annex A & B]
    C --> D[IS 1150:1976 Nomenclature]
    A --> E[Volume = L × W × T (m³)]

This ensures uniformity in timber terminology, species identification, and measurement for structural use.

IS 1326: Species Covered & Key Specifications

Species Covered:

• Covers non-coniferous Indian timbers (Annex A & B).
• Species nomenclature and abbreviations follow IS 1150:1976.
• Examples from Annex A (Non-coniferous species):

Marking Requirements (Clause 10.1): Each timber piece must be marked with:

• Species name (abbreviation per Annex A)
• Dimensions
• Supplier's name/initials/trademark
• Year of supply

Additional References:

• IS 190:1991 for coniferous sawn timber (baulks and scantlings).
• IS 401, 707, 1141, 1150 for timber preparation, seasoning, terminology, and species symbols.

Summary Diagram: Timber Marking Process

flowchart TD
    A[Timber Inspection] --> B[Marking on Timber]
    B --> C[Species Abbreviation]
    B --> D[Dimensions]
    B --> E[Supplier Info]
    B --> F[Year of Supply]

This ensures traceability and standardization for timber species and quality per IS 1326.

IS 1326 – Dimensions and Measurements (Clause 5.2)

• Width & Thickness Measurement (5.2.2):
  Measure at the narrowest point, rounded to the nearest 10 mm.

• Volume Calculation (5.2.3):
  [ \text{Volume (m}^3) = \text{Length (m)} \times \text{Width (m)} \times \text{Thickness (m)} ]
  Rounded to 3 decimal places.

• Reference Standards:

  • IS 707:1976 – Glossary & definitions
  • IS 1150:1976 – Timber species nomenclature
  • IS 401, 1141, 1150 – Preparation, seasoning, and evaluation of timber defects

Summary Table for Measurement

This ensures uniformity in timber sizing and volume calculation as per IS 1326.

IS 1326: Requirements and Grading of Non-Coniferous Sawn Timber

Volume Calculation (Clause 5.2.3)

• Volume (m³) = Length × Width × Thickness
• Accurate to 3 decimal places based on accepted sizes.

Grading & Defect Limits (Clause 6.2, 7.1, 7.2)

Additional Notes

• End splits: Longest splits ≤ 80 mm/m (Special Grade), ≤ 100 mm/m (Grade 1), not allowed in Grade 2.
• Defects measured as per **IS 336

IS 1326: Prohibited and Permissible Defects in Non-Coniferous Sawn Timber

1. Prohibited Defects (Clause 7.1)

• All grades: No spiral/twisted grain, warp, decay, live insect attack.
• Special Grade: Also free from center heart, wane, cup shakes, borer holes (dead infestation), sapstain (blue stain), knots.
• Grade 1: No cup shakes.

2. Permissible Defects (Table 1 Summary)

3. Additional Specifications

Prophylactic Treatment as per IS 1326 (Clause 8)

• Reference Standard: IS 401 : 1982 (Code of Practice for Preparation of Timber)
• Purpose: To prevent/minimize defects like end cracking, splitting.
• End Coating:
  • Apply coating on ends of each baulk/scantling up to:
    • 150 mm, or
    • At least 25 mm more than the length of the largest split, whichever is greater.
  • Use materials specified in IS 1141 : 1973 (Code of Practice for Seasoning of Timber).
  • Coating must be applied immediately after inspection of timber.

Key Specifications

Summary Diagram

flowchart TD
    A[Timber Inspection] --> B[Measure Largest Split Length]
    B --> C{Is 150 mm > (Largest Split + 25 mm)?}
    C -->|Yes| D[Apply End Coating up to 150 mm]
    C -->|No| E[Apply End Coating up to Largest Split + 25 mm]
    D & E --> F[Use Coating Materials per IS 1141:1973]
    F --> G[Prevents End Cracking & Splitting]

This prophylactic treatment ensures durability and quality of timber by controlling moisture loss and mechanical damage at ends.

IS 1326 - Marking of Timber (Clause 10.1 & 10.1.1)

Immediately after inspection, each timber piece shall be marked legibly and indelibly about 300 mm from the end with:

• a) Name of species (use abbreviations from Annex A)
• b) Dimensions of the piece (Length × Width × Thickness)
• c) Supplier's name, initials, or registered trademark
• d) Year of supply

Optional: Marking with the Standard Mark as per Clause 10.1.1.

Annex A: Abbreviations for Timber Species (Sample)

(Refer IS 1326 Annex A for full list)

Key Points:

• Marking ensures traceability and identification.
• Dimensions must be accurate (see Clause 5.2.3 for volume calculation).
• Use standard abbreviations for species to maintain uniformity.

Volume Calculation (Clause 5.2.3):

[ \text{Volume (m}^3) = \frac{\text{Length (mm)} \times \text{Width (mm)} \times \text{Thickness (mm)}}{1,000,000,000} ]

(Convert mm³ to m³ by dividing by 10^9)

flowchart LR
    A[Timber Piece] --> B[Inspection]
    B --> C[Marking at 300 mm from end]
    C --> D[Species Name (Abbreviation)]
    C --> E[Dimensions]
    C --> F[Supplier Info]
    C --> G[Year of Supply]
    C --> H[Optional: Standard Mark]

Summary: Mark timber clearly with species abbreviation, dimensions, supplier, and year near the

IS 1326: Inspection and Sampling - Key Points

1. Permissible Defects (Clause 7.2)

• Defects allowed as per Table 1 for different timber grades.
• Measured according to IS 3364 (Part 2): 1976.
• Defects include splits, shakes, knots, etc., with limits varying by grade.

2. Prophylactic Treatment (Clause 8)

• Treatment as per IS 401:1982 (code of practice for timber preparation).
• Ends of timber baulks/scantlings coated up to 150 mm or 25 mm beyond longest split (whichever is more) per IS 1141:1973.
• Coating applied immediately after inspection to prevent end cracking.

3. Measurement and Volume (Clause 5.2.3)

• Volume ( V ) in cubic meters:

  [ V = \text{Length} \times \text{Width} \times \text{Thickness} ]

• Dimensions based on accepted sizes, volume rounded to 3 decimal places.

4. Standards Referenced

• IS 401:1982 (Timber preparation)
• IS 3364 (Part 2):1976 (Defect measurement)
• IS 1141:1973 (Seasoning & end coating)
• IS 707:1976 (Glossary)
• IS 1150:1976 (Species nomenclature)

Summary Table: Inspection & Sampling Essentials

flowchart TD
    A[Timber Inspection

IS 1326 - Non-Coniferous Timber Species Key Data

1. List of Non-Coniferous Timber Species (Annex A excerpt)

(The full list is extensive; refer to IS 1326 Annex A for complete details.)

2. Specifications & Standards Referenced

• IS 1150:1976 — Trade names and abbreviated symbols for timber species.
• IS 707:1976 — Glossary of timber terms.
• IS 401:1982 — Preparation of timber.
• IS 1141:1973 — Seasoning of timber.
• IS 190:1991 — Coniferous timber specification (adjunct to IS 1326).

3. Key Notes

• Non-coniferous timber is mainly marketed as baulks and scantlings.
• Timber species are identified by standard trade names and abbreviated symbols.
• Marking with the Standard Mark is recommended (Clause 10.1.1).
• Dimensions and measurement methods follow IS 401 and IS 1141.

Summary Diagram: Timber Species Identification Flow

flowchart TD
    A[Timber Sample] --> B{Identify Species}
    B -->|Visual/ Botanical| C[Match Trade Name]
    C --> D[Assign Abbreviated Symbol (IS 1150)]
    D --> E[Mark with Standard Mark (