Corrugated coir wood wool cement roofing sheets-Specification

IS 10388 - Scope & Key Specifications

1. Scope (Clause 3.1)

• Applies to corrugated coir/woodwool cement roofing sheets.
• Sheets must conform to specified dimensions and tolerances (Table 1).

2. Dimensions and Tolerances (Table 1)

• Thickness measured as average of 6 readings (except valleys).
• Depth measured on 6 corrugations; max deviation within tolerance.
• Pitch measured over 6 corrugations.

3. Chemical Test Formula (Acetic Acid Content)

[ \text{Acetic acid (g/m}^2) = \frac{0.030 \times 270 \times (x - y)}{A} \times 10^6 = \frac{0.81 \times (x - y)}{A} \times 10^6 ]

• (x) = initial ml of 0.5N NaOH
• (y) = final ml of 0.5N NaOH
• (A) = area in mm² of specimen

Summary Diagram: Dimensions & Tolerances

graph LR
A[Sheet Dimensions] --> B[Length: 1500/1750/2000 ±10 mm]
A --> C[Width: 1000 ±10 mm]
A --> D[Thickness: 6.5 + free/-0.5 mm]
A --> E[Depth of Corrugation: 48 +3/-6 mm]
A --> F[Pitch of Corrugation: 146 +6/-2 mm (6 pitches)]

Note: Sheets may be supplied in other sizes if agreed between purchaser and manufacturer.

IS 10388 - Materials: Key Formulas, Tables & Specifications

1. Acetic Acid Usage Calculation (Clause 3.1)

To find the weight of acetic acid used per m² of specimen:

[ \text{Weight of acetic acid (g/m}^2) = 0.030 \times 270 \times \frac{(x - y)}{A} \times 10^6 = 0.81 \times \frac{(x - y)}{A} \times 10^6 ]

• x = Initial volume (ml) of 0.5 N NaOH used in titration
• y = Final volume (ml) of 0.5 N NaOH used
• A = Area of specimen in mm² (unprotected coir/woodwool cement)

2. Dimensions & Tolerances (Table 1, Clause 3.1)

• Thickness measured as average of 6 readings along width (excluding valleys).
• Depth measured using depth gauge; max deviation as above.
• Pitch tolerance measured over six pitches.

3. Physical Requirements (Table 2, Clause 4.1)

4. Units (SI Units)

• Length: metre (m)
• Mass: kilogram (kg)
• Pressure/Stress: pascal (Pa)

IS 10388: Dimensions and Tolerances for Corrugated Coir, Woodwool, Cement Roofing Sheets

Key Dimensions & Tolerances (Table 1, Clause 3.1)

Important Notes:

• Thickness: Average of six measurements along width (excluding valleys) using a screw gauge.
• Depth of Corrugation: Measured on six corrugations; max deviation within tolerance using a depth gauge.
• Pitch of Corrugation: Measured over six pitches; total length must be within tolerance of 6 × specified pitch.

Acceptance Criteria (Clause 7.2.1)

• Sheets failing dimensional requirements are defective.
• Lot acceptance depends on the number of defectives ≤ acceptance number (Table 3).

flowchart TD
    A[Measure Sheet Dimensions] --> B{Check Length ±10mm}
    B -- Yes --> C{Check Width ±10mm}
    B -- No --> D[Reject Sheet]
    C -- Yes --> E{Check Thickness +free/-0.5mm}
    C -- No --> D
    E -- Yes --> F{Check Depth of Corrugation +3/-6mm}
    E -- No --> D
    F -- Yes --> G{Check Pitch of Corrugation +6/-2mm}
    F -- No --> D
    G -- Yes --> H[Accept Sheet]
    G -- No --> D

This ensures quality control in roofing sheets per IS 10388.

IS 10388: Physical Requirements for Woodwool, Coir/Cement Corrugated Roofing Sheets

Key Physical Requirements (Clause 4.1 & Table 2)

Dimensions & Tolerances (Clause 3.1, Table 1)

• Thickness measured as average of 6 readings (except valleys).
• Depth measured with depth gauge for 6 corrugations.
• Pitch tolerance over six pitches.

Acid Resistance Calculation (Appendix D-3.1)

[ \text{Acetic acid used (g/m}^2) = 0.030 \times \frac{(x - y) \times 10^6}{A} = 0.81 (x - y) \times \frac{1}{A} ]

• (x) = initial ml of 0.5N NaOH
• (y) = final ml of 0.5N NaOH
• (A) = specimen area in mm²

Sampling (Clause 7.1.3, Table 3)

IS 10388: Sampling and Testing Key Points

1. Sampling Sizes & Acceptance Criteria (Clause 7.1.3, Table 3)

• Dimensional tests sample size from column 2.
• Physical tests sample size from column 4.
• Acceptance number (max allowed defective) from column 3.

2. Testing Criteria (Clause 7.2.2)

• Physical tests include wet breaking load, water absorption, impermeability, acid resistance.
• Only lots conforming to dimensional requirements proceed to physical tests.
• Use sample sizes per Table 3 column 4.

3. Acid Resistance Calculation (Clause 3.1, Table D-3)

[ \text{Weight of acetic acid (g/m}^2) = 0.030 \times \frac{(x - y) \times 10^6}{A} ]

Where:

• (x) = volume (ml) of 0.5 N NaOH at initial titration
• (y) = volume (ml) of 0.5 N NaOH at final titration
• (A) = area (mm²) of specimen

4. Test Result Reporting

• Average of 3 specimens per sheet is used as the sheet test result.

Summary Flowchart of Sampling & Testing

flowchart TD
    A[Start: Lot Received] --> B[Select Sample for Dimensional Tests (Table 3 col 2)]
    B --> C{Dimensional Tests Passed?}
    C -- Yes --> D[Select Sample for Physical Tests (Table 3 col 4)]
    C -- No --> E[Reject Lot]
    D --> F[Conduct Physical Tests: Wet Breaking Load, Water Absorption, Imper

IS 10388: Manufacture of Corrugated Coir, Woodwool, Cement Roofing Sheets

Key Specifications & Tolerances (Clause 3.1 & Table 1)

• Thickness measured as average of six readings along width (excluding valleys).
• Depth measured with depth gauge; max deviation per corrugation must meet tolerance.
• Pitch tolerance measured over six pitches cumulatively.

Manufacture Notes (Clause 3.1.1)

• Sheets can be made in other dimensions if agreed between purchaser and manufacturer.
• Numerical values must be rounded off as per IS 2-1960 rules.

Chemical Test Formula (Clause D-3.1)

To calculate acetic acid used per m²:

[ \text{Acetic acid (g/m}^2) = 0.030 \times \frac{(x - y) \times 10^6}{A} = 0.81 (x - y) \times \frac{1}{A} ]

• (x) = ml of 0.5 N NaOH at initial titration
• (y) = ml of 0.5 N NaOH at final titration
• (A) = area of specimen in mm²

Summary

• Follow dimensional tolerances strictly for quality.
• Thickness and corrugation depth must be checked carefully.
• Chemical resistance checked by titration method using above formula.
• Custom sizes allowed with purchaser's consent.

flowchart LR
    A[Raw Materials] --> B[Sheet Formation]
    B --> C[Thickness & Corrugation Measurement]
    C --> D{Within Tolerance?}
    D -- Yes --> E[Chemical Testing]
    D -- No --> F[Reject/Reman

IS 10388: Inspection and Acceptance Criteria (Clause 7.1.3, 7.2)

Key Table: Sample Size & Acceptance Numbers (Table 7.2)

Inspection Criteria:

• Dimensional Requirements (Clause 7.2.1):

  • Test the sample size as per column 2.
  • If defectives ≤ acceptance number (col 3), lot conforms.
  • If defectives > acceptance number, lot is rejected without further testing.

• Finish Requirements (Clause 7.1.2):

  • Inspect all sheets for finish defects.
  • Remove all defective sheets from the lot.

Summary:

• Use Table 7.2 for determining sample sizes and acceptance criteria.
• Dimensional defects are critical for lot acceptance; physical tests have separate sample sizes.
• Finish defects lead to removal of defective sheets but do not necessarily reject the entire lot.

flowchart TD
    A[Start: Lot Received] --> B[Inspect Finish of All Sheets]
    B --> C{Defective Sheets?}
    C -- Yes --> D[Remove Defective Sheets]
    C -- No --> E[Select Sample for Dimensional Test]
    E --> F{Defectives ≤ Acceptance Number?}
    F -- Yes --> G[Lot Accepted]
    F -- No --> H[Lot Rejected]

IS 10388: Test Methods - Key Formulas & Tables

1. Acid Resistance Test (Clause D-3.1)

• Formula to calculate acetic acid used per m²:

[ \text{Weight of acetic acid (g/m}^2) = \frac{0.030 \times 270 \times (x - y)}{A} \times 10^6 = 0.81 \times \frac{(x - y)}{A} \times 10^6 ]

Where:

• ( x ) = volume (ml) of 0.5 N NaOH at initial titration
• ( y ) = volume (ml) of 0.5 N NaOH at final titration
• ( A ) = area of specimen in mm² (specimen size: 65 × 65 mm = 4225 mm²)

2. Sample Size and Acceptance Criteria (Clause 7.1.3, Table 3)

3. Physical Requirements (Table 2, Clause 4.1)

4. Additional Notes

• Average of 3 specimens per sheet is considered the test result.
• Specimen size for acid resistance: 65 × 65 mm.
• Moisture traces allowed on lower surface during 24-hour impermeability test but no drop formation.

IS 10388: Marking and Packaging Key Points

Marking (Clause 6.1 & 6.2)

• Each sheet must be marked with:
  • Manufacturer’s name or trademark.
  • Year and date of manufacture.
• Optional: ISI Certification Mark may be used following the Indian Standards Institution (ISI) rules, ensuring quality compliance.

Sampling and Conformity (Clause 7.1.3, Table 7.2)

• Acceptance number: Maximum permissible defects in the sample.
• Sampling ensures quality control for both dimensional and physical properties.

Packaging

• Not explicitly detailed in the provided clauses.
• Typically, packaging should protect sheets from damage and contamination during transport and storage.

flowchart TD
    A[Manufacture of Sheets] --> B[Marking]
    B -->|Info| C[Manufacturer's Name, Date]
    B -->|Optional| D[ISI Certification Mark]
    A --> E[Sampling]
    E --> F[Dimensional Tests]
    E --> G[Physical Tests]
    F & G --> H[Acceptance Criteria]

Summary: Mark sheets clearly with manufacturer info and date; apply ISI mark if licensed. Follow sampling sizes per lot for quality checks. Packaging should ensure protection but is not detailed in IS 10388.

IS 10388: Test Procedures for Transverse Strength

Key Specifications & Procedure (Clause 2.1, Appendix A)

• Sample Conditioning: Immerse sheets in water at 27 ± 2°C for 24 hours.
• Support Setup:
  • Sheets supported on parallel hardwood bearers (75 mm wide × 150 mm deep).
  • Bearers spaced 1 m center-to-center, perpendicular to corrugations.
• Load Application:
  • Load applied at uniform rate ≤ 20 N/min.
  • Load applied through a 225 mm × 75 mm runner along the sheet centerline, parallel to supports.

Test Calculation (Clause 3.1)

• Record the breaking load.
• Compute load per meter width of the sheet.

Acceptance Criteria (Clause 7.2.2.2)

• Let:
  • X = average of test results,
  • R = range of test results,
  • Minimum limit from Table 2 (Appendix A).
• The lot conforms if:

[ X - 0.5R \geq \text{Minimum limit from Table 2} ]

Summary Table (Example format from Table 2, Appendix A)

flowchart TD
    A[Prepare sheet sample] --> B[Immerse in water at 27±2°C for 24h]
    B --> C[Place on hardwood bearers (75x150 mm), 1m apart]
    C --> D[Apply load at ≤20 N/min through 225x75 mm runner]
    D --> E[Record breaking load]
    E --> F[Calculate load per meter width]
    F --> G[Check if X - 0.5R ≥ min limit from Table 2]
    G -->|Yes| H[Lot conforms]
    G -->|No| I[Lot rejected]

This ensures reliable evaluation of transverse strength per IS 10388.

IS 10388: Water Absorption Test Method

Key Formula (Clause 3.1)

Water Absorption (%) is calculated as:

[ \text{Absorption} = \frac{W_1 - W_2}{W_2} \times 100 ]

• W1 = Weight after absorption (g)
• W2 = Weight after heating (g)

Specifications (Appendix C, Table 2, Item iii)

• Maximum Water Absorption: 30%
• Impermeability: Minimum 1.5 × 10⁻³ N/m width
• No visible water drops except traces of moisture on the lower surface.

Testing Notes

• Specimens must be at least 4 weeks old before testing.
• For compliance, the formula (X + 0.5R \leq \text{limit}) applies, where:
  • X = Mean test value
  • R = Range of test values (Clause 7.2.2.3)

This ensures durability and impermeability of the sheets per IS 10388 standards.

IS 10388: Impermeability Test Key Points

Water Absorption Formula (Clause 3.1 B-3.1)

[ \text{Absorption %} = \frac{W_1 - W_2}{W_2} \times 100 ]

• W1 = Weight after absorption (g)
• W2 = Weight after heating (g)

Impermeability Test Requirements (Clause 7.2.2 & 7.2.2.1)

• Test performed on samples conforming to dimensional requirements.
• Sample size per Table 3 (cols 1 & 4) of IS 10388.
• No defects allowed in the sample after testing.
• During 24 hours, moisture traces may appear on the lower surface but no water drops should form (Clause 3.1 C-3.1).

Sample Size & Specimen Dimensions

• Specimens for acid resistance (related test) are 65 × 65 mm (Appendix D).

Summary Table for Impermeability Test

flowchart LR
    A[Sample Conforms to Dimensions] --> B[Impermeability Test]
    B --> C{After 24 hrs}
    C -->|No moisture| D[Pass]
    C -->|Moisture traces only| D
    C -->|Water drops formed| E[Fail]
    C -->|Defects found| E

This ensures the tile's impermeability per IS 10388 standards.

IS 10388: Acid Resistance Test & Reporting Summary

Specimen Preparation (Appendix D)

• Specimen size: 65 × 65 mm (actual edge length)
• Number: 3 specimens per sheet
• Age of specimens: ≥ 4 weeks

Test Procedure (Clause D-2.1)

• Immerse each specimen upright in 270 ml of 5% acetic acid at 27 ± 2°C for 24 hours.
• Use separate vessels and fresh acid solution for each specimen.
• Measure acid concentration before and after immersion by titration:
  • Take 10 ml acid solution → dilute to 100 ml
  • Add 10 drops thymol blue (0.040 g/100 ml in 95% alcohol)
  • Titrate with ~0.5 N NaOH
  • Endpoint: color change yellow → blue (pH 8.0–9.5)

Acceptance Criteria (Clause 3.1, 1.5, 7.2.2.3)

• Formula for compliance:

[ X + 0.5R \leq \text{Upper limit (from Table 2)} ]

Where:

• (X) = mean value
• (R) = range of test values

Reporting

• Report water absorption, acid consumption (g/m²), and visual observations (moisture/droplets).
• Confirm titration results and specimen age.
• State compliance with limits.

flowchart TD
    A[Specimen Preparation] --> B[Immersion in 5% Acetic Acid]
    B --> C[Titration Before & After]
    C --> D[Calculate Acid Consumption]
    D --> E{Check Limits}
    E -->|Pass| F[Report Compliance]
    E -->|Fail| G[Reject Specimen]

This ensures durability evaluation of cement sheets against acid attack per IS 10388.