corrugated bitumen roofing sheets

IS 12583: Key Specifications & Tables from Foreword

Standard Sizes of Sheets (Clause 3.1)

• Tolerance in thickness: +1 mm (Clause 3.2 Note)

Mass of Sheets (Clause 4.1, Table 2)

Paper Board Requirements (Table 1)

Notes:

• Corrugation depth and pitch are critical for structural rigidity.
• Mass values help in quality control and design calculations.
• Paper board physical properties ensure durability and performance.

flow

IS 12583: Scope – Key Specifications & Tables

Standard Sheet Sizes (Clause 3.1)

Mass of Sheets (Clause 3.2, Table 2)

Permissible Tolerances on Dimensions (Clause 3.2)

• Thickness measured as average of six readings along width using a screw gauge (anvil diameter 9 mm).

Notes:

• Corrugation depth and pitch are fixed at 35 mm and 90 mm respectively.
• Thickness tolerance ensures manufacturing consistency.
• Mass values help in structural load calculations.

flowchart LR
    A[Standard Sheet] --> B{Dimensions}
    B --> C[Length: 1800 mm ±5]
    B --> D[Width: 900 mm ±20]
    B --> E[Thickness: 3-5 mm +1 tolerance]
    A --> F[Corrugation]
    F --> G[Depth: 35 mm]
    F --> H[Pitch: 90 mm]
    A --> I[Mass]
    I --> J[3 mm: 5.4 ±0.2 kg]
    I --> K[4 mm: 7.2 ±0.2 kg]
    I --> L[5 mm: 9.0 ±0.2 kg]

This summary covers the scope-related dimensions, tolerances, and mass data essential for design and quality control per IS 12583.

IS 12583: Key Specifications & Tables for Materials

1. Sheet Dimensions & Tolerances (Clause 3.1 & 3.2)

• Thickness tolerance: +1 mm
• Length tolerance: ±5 mm
• Width tolerance: ±20 mm
• Thickness measured as average of 6 points along width using a screw gauge (anvil diameter 9 mm).

2. Mass of Sheets

3. Material Characteristics & Requirements (Clause 5.1)

4. Measurement Notes

• Thickness is the average of six measurements.

IS 12583: Dimensions and Tolerances for Bitumen Roofing Sheets

1. Standard Dimensions (Clause 3.1)

2. Permissible Tolerances (Clause 3.2)

3. Mass Specification (Clause 3.2, Table 2)

Measurement Notes:

• Thickness is averaged from six measurements across the width.
• Use a screw gauge with a 9 mm diameter anvil for thickness measurement.

flowchart LR
    A[Sheet Dimensions] --> B[Length: 1800 ±5 mm]
    A --> C[Width: 900 ±20 mm]
    A --> D[Thickness: 3-5 mm, +1 mm tolerance]
    D --> E[Measured as avg of 6 readings]
    A --> F[Corrugation Depth: 35 mm]
    A --> G[Corrugation Pitch: 90 mm]

This ensures correct sizing and quality control per IS 12583.

IS 12583: Corrugated Bitumen Roofing Sheets - Key Specifications

1. Standard Dimensions (Clause 3.1, Table 2)

2. Material Requirements (Clause 2.2)

• Paper board used must conform to specified physical and chemical properties (see Table 1 in IS 12583).
• Bitumen used should comply with IS paving bitumen standards (revised).

3. General Requirements

• Sheets are lightweight roofing materials.
• Thickness tolerance and dimensional accuracy as per IS 12583.
• Corrugation profile ensures strength and water runoff.

Visual: Corrugated Sheet Profile

graph LR
A[Sheet Length 1200 mm] --> B[Width 750 mm]
B --> C[Corrugation Depth 35 mm]
C --> D[Pitch 90 mm]
D --> E[Thickness 3-5 mm]

This summary aids in selecting and verifying corrugated bitumen roofing sheets per IS 12583.

IS 12583: Appearance and Finish - Key Points

Visual & Dimensional Requirements (Clauses 2.2, 5.1, 6.1)

• Sheets must be true shape, good appearance, free from visible defects (cracks, sagging, color change).
• Corrugations should be true and regular; edges straight and clean.
• Both surfaces painted with aluminium paint.
• Moisture formation and cracks on the underside must be recorded (average of 2 determinations).
• Average of 5 determinations reported for surface defects compared to unexposed sheets.

Sampling & Acceptance Criteria (Clause 2.2, M-2.2)

• Sample sheets are examined visually and dimensionally.
• If defective sheets ≤ permissible number (Table 4, col 3), lot is accepted.
• If defective sheets > permissible number, lot is rejected.

Testing Assemblies (Figures 3 & 4)

• Wooden purlins (50×50 mm) used for wet load bearing capacity test.
• Sand retention and supporting frames detailed for testing setup.

Summary Table: Visual Defect Reporting

Note:

For detailed permissible defect numbers and sampling sizes, refer to Table 4 and Appendices J & K of IS 12583.

flowchart TD
    A[Sheet Selection] --> B[Visual & Dimensional Inspection]
    B --> C{Defective Sheets ≤ Permissible?}
    C -->|Yes| D[Lot Accepted]
    C -->|No| E[Lot Rejected]
    B --> F[Record Defects: Cracks, Sagging, Moisture]
    F --> G[Report Average Values]

IS 12583 - Packing of Sheets: Key Specifications & Tables

Packing Requirements (Clause 7.1)

• Sheets must be packed per usual trade practice.
• Purpose: Prevent damage, discoloration, deformation.

Marking on Packages (Clause 8.1)

Each package must be clearly marked with:

• Manufacturer's name or trademark.
• Batch number, month, and year of manufacture.
• Dimensions of sheets.

Physical Requirements & Weight (Clause 4.1 & Table 2)

Paper Board Requirements (Table 1)

Summary:

• Use Table 2 for sheet mass control.
• Ensure proper packing to avoid damage.
• Mark packages with manufacturer info, batch, and dimensions.
• Follow physical property requirements from Table 1.

flowchart TD
    A[Sheets Produced] --> B{Packing}
    B -->|Trade Practice| C[Protect from Damage]
    C --> D[Mark Package]
    D --> E[Ship]

This ensures sheets maintain quality until use.

IS 12583: Marking Specifications & Key Tables

Marking Requirements (Clause 8.1)

Each package/sheet shall be legibly and indelibly marked with:

• Manufacturer's name or trademark
• Batch number, month, and year of manufacture
• Dimensions (Length, Width, Thickness)

Standard Mark (Clause 8.1.1)

• Use of the Standard Mark is regulated by BIS.
• Indicates compliance with IS 12583 under BIS supervision.
• Licensing conditions for Standard Mark use are governed by BIS rules.

Key Dimensions & Tolerances (Clause 3.1, 3.2)

• Thickness tolerance: +1 mm

Mass Table (Clause 3.2)

Sampling & Conformity (Clause 2.2)

• Sheets failing visual/dimensional checks are defective.
• Lot acceptance depends on permissible number of defectives (see Table 4 in IS 12583).
• Sampling scale and criteria apply for other properties (wet load, weathering, temperature).

This concise summary covers marking and key dimension/mass specs per IS 12583. For detailed sampling tables and visual criteria, refer to the full standard.

IS 12583: Sampling and Criteria for Conformity (Appendix M)

Key Points:

• Sampling Procedure (Clause 9.1, M-1.2):

  • Each lot is sampled individually.
  • Samples are taken randomly following simple random sampling as per IS 4905:1968.

• Criteria for Conformity:

  • Visual and dimensional requirements are checked according to a defined sampling scale.
  • Lot acceptance depends on meeting specified limits for defects and dimensions.

Sampling Scale & Acceptance Criteria (Typical from IS 4905):

• Acceptance number (Ac): Max defects allowed to accept the lot.
• Rejection number (Re): Minimum defects to reject the lot.

Additional Notes:

• The Standard Mark (Clause 8.1.1) certifies compliance and ongoing quality control by BIS.
• Sampling ensures quality consistency and compliance with IS 12583 requirements.

flowchart TD
    A[Lot Received] --> B[Random Sampling as per IS 4905]
    B --> C{Check Visual & Dimensional Requirements}
    C -->|Defects ≤ Ac| D[Accept Lot]
    C -->|Defects ≥ Re| E[Reject Lot]

This ensures reliable quality control for corrugated bitumen roofing sheets.

IS 12583: Determination of Bitumen Content in Corrugated Bitumen Roofing Sheets

Key Specifications (Clause 5.1 Table):

Method Summary (Appendix A - Clause 4.1):

• Bitumen content is determined by extracting asphalt from outer and central layers separately.
• Use solvent extraction or heating methods as per Appendix A procedures.
• Calculate bitumen % as:

[ \text{Bitumen Content (%)} = \frac{\text{Mass of bitumen extracted}}{\text{Mass of sample}} \times 100 ]

Additional Notes:

• Uniformity check ensures consistent bitumen distribution.
• Ash content limits ensure minimal filler or impurities.
• Testing apparatus includes solvent extractor, drying oven, and balance.

flowchart TD
    A[Sample Collection] --> B[Separate Outer & Central Layers]
    B --> C[Solvent Extraction of Bitumen]
    C --> D[Dry & Weigh Bitumen Extracted]
    D --> E[Calculate % Bitumen Content]
    E --> F{Is bitumen content ≤ 50 ± 5%?}
    F -- Yes --> G[Pass]
    F -- No --> H[Fail]

This ensures quality control for roofing sheets per IS 12583.

IS 12583: Determination of Uniformity of Impregnation

Key Specifications (Clause 5.1 & Appendix B)

• Uniformity of impregnation: Bitumen content in outer and central layers of the sheet shall not vary by more than 5%.
• Bitumen content is expressed as a percentage of original mass.
• Average of two test samples recorded to the nearest 0.1%.

Procedure Highlights (Appendix B)

• Measure bitumen content separately in outer and central layers.

• Calculate percentage bitumen content for each layer:

  [ \text{Bitumen content %} = \frac{\text{Mass of bitumen}}{\text{Original mass of sample}} \times 100 ]

• Uniformity criterion:

  [ | \text{Bitumen content}{outer} - \text{Bitumen content}{central} | \leq 5% ]

Apparatus (Clause 6.1.4)

• Use glass tube (25 mm I.D.) and empty glass beaker (100 ml) for impregnation tests.
• Average of all determinations is taken.

Summary Table

flowchart TD
    A[Sample Preparation] --> B[Separate Outer & Central Layers]
    B --> C[Measure Mass of Bitumen in Each Layer]
    C --> D[Calculate % Bitumen Content]
    D --> E{Difference ≤ 5%?}
    E -- Yes --> F[Uniformity Acceptable]
    E -- No --> G[Reject Sample]

Note: Accurate weighing and layer separation are critical for reliable uniformity determination.

IS 12583: Determination of Ash Content in Corrugated Asphaltic Roofing Sheets

Key Steps (Clause 4.1):

• Transfer sample piece into a silica crucible and weigh.
• Cover with lid and ignite until constant mass is achieved (complete combustion of organic matter).

Formula (Clause 5.1):

[ \text{Ash Content (%)} = \frac{\text{Mass of Ash}}{\text{Mass of Original Sample}} \times 100 ]

Notes:

• Mass of ash = weight of crucible + ash after ignition - weight of empty crucible.
• Report difference in asphalt content between layers if multilayered (Clause B-5.1).
• Table 3 (SI No. iii) provides reference values for ash content limits (refer IS 12583 for exact values).

flowchart TD
    A[Sample in crucible] --> B[Weigh crucible + sample]
    B --> C[Ignite to constant mass]
    C --> D[Weigh crucible + ash]
    D --> E[Calculate ash content %]

Summary: Ash content quantifies non-combustible residue, critical for quality control of roofing sheets.

IS 12583: Determination of Breaking Load

Key Specifications:

• Test Span: 600 mm (for paper board, span is 300 mm)
• Support Setup: Two parallel wooden supports with a third wooden piece placed midway on the test sample (per Fig. 1).
• Loading: Load applied gradually using common building bricks until failure.

Procedure:

• Conduct three determinations of breaking load.
• Calculate the average breaking load from all three tests (Clause 3.1).
• Record the average to the nearest 0.1% (Clause 5.2).

Summary Table (from Table 3, SI No. iv):

Formula for Average Breaking Load:

[ P_{avg} = \frac{P_1 + P_2 + P_3}{3} ]

Where:

• (P_1, P_2, P_3) = Breaking loads from three tests.

Visual Setup (Fig. 1):

graph LR
A[Wooden Support] --- B[Test Sample]
B --- C[Wooden Support]
D[Load applied via wooden piece] --> B

This method ensures consistent and accurate determination of breaking load for paper and board samples as per IS 12583.

IS 12583: Water Absorption for Corrugated Asphaltic Roofing Sheets

Key Specifications:

• Max Water Absorption: 8% by mass (Clause E-5.1 (v))
• Number of Tests: Average of 5 determinations (Clause E-4.1)
• Reporting Precision: Nearest 0.1%

Test Procedure Summary (Appendix E):

1. Specimen Preparation: Dry the test specimen and record original mass ( M_0 ).
2. Water Immersion: Immerse specimen in water for specified duration.
3. Post-Immersion Mass: Remove, surface dry, and weigh specimen ( M_1 ).
4. Calculate Water Absorption:

[ \text{Water Absorption (%)} = \frac{M_1 - M_0}{M_0} \times 100 ]

5. Report: Average of 5 specimens to nearest 0.1%.

Quick Reference Table for Water Absorption

Notes:

• All dimensions in mm.
• Ensure uniform drying and immersion conditions.
• Water absorption affects durability and impermeability.

flowchart TD
    A[Dry Specimen] --> B[Weigh Original Mass \(M_0\)]
    B --> C[Immerse in Water]
    C --> D[Remove & Surface Dry]
    D --> E[Weigh Mass After Immersion \(M_1\)]
    E --> F[Calculate Water Absorption %]
    F --> G[Repeat for 5 Specimens]
    G --> H[Report Average Value]

This ensures compliance with IS 12583 for roofing sheet quality control.

IS 12583: Determination of Impermeability – Key Points

1. Mass Increase Calculation (Clause 4.1)

• Calculate percentage increase in mass after water exposure:

  [ % \text{Increase} = \frac{(M_{wet} - M_{dry})}{M_{dry}} \times 100 ]

• Report average of 5 determinations to nearest 0.1%.

2. Test Apparatus (Clause 6.1.4 & Fig. 2)

• Use Glass Tube (25 mm I.D.) and Empty Glass Beaker (100 ml).
• Measure water penetration or absorption through specimen.

3. Test Specimen & Reporting (Clause F-2, 3.1)

• Use standard specimen dimensions (in mm).
• Report average of 3 determinations.

Summary Table (from Appendix F & G):

Practical Notes:

• Ensure specimens are dried before initial weighing.
• Maintain consistent water temperature during test.
• Average values ensure repeatability and reliability.

flowchart TD
    A[Prepare Dry Specimen] --> B[Weigh Dry Mass (M_dry)]
    B --> C[Immerse in Water for Specified Time]
    C --> D[Remove & Surface Dry Specimen]
    D --> E[Weigh Wet Mass (M_wet)]
    E --> F[Calculate % Increase]
    F --> G[Repeat 5 Times]
    G --> H[Report Average % Increase]

This method ensures reliable determination of impermeability of corrugated asphaltic roofing sheets as per IS 12583.