Clay Roofing Tiles, Mangalore Pattern-Specification

IS 654: Scope, Key Dimensions & Specifications for Roofing Tiles

1. Scope:

IS 654 covers burnt clay roofing tiles with specific sizes and quality classes.

2. Tile Sizes (Clause 6.1, Table 2):

3. Quality Classes (Table 1):

4. Notes:

• Overlaps can be adjusted to fit larger batten spacing.
• Test results must be rounded per IS 2:1960 rules.

This summary provides essential tile dimensions, quality classes, and mechanical properties for compliance with IS 654.

IS 654 Key References: Roofing Tiles

1. Classification of Tiles (Table 1, Clause 8.1)

2. Dimensions of Tiles (Table 2, Clause 6.1)

• Overlaps can be adjusted to use smaller tiles for larger batten spacings (up to 350 and 360 mm).

3. Rounding Off (Clause 6)

• Follow IS 2:1960 for rounding test results.
• Retain significant digits as per specified values.

This summary helps ensure compliance with IS 654 for tile selection, sizing, and quality control.

IS 654: Terminology & Key Specifications for Roofing Tiles

Terminology

• Definitions follow IS 2248:1991 (Clay Roofing Tiles).

Tile Sizes (Clause 6.1, Table 2)

Note: Overlaps can be adjusted to extend batten spacing.

Classification & Properties (Clause 8.1, Table 1)

Rounding Off Values

• Follow IS 2:1960 rules for rounding test results, keeping significant figures consistent with specified values.

This summary aids in selecting tiles per size, quality class, and mechanical/water absorption criteria as per IS 654.

Classification of Roofing Tiles (IS 654 - Clause 4 & 8.1)

Roofing tiles (Mangalore Pattern) are classified into Class AA and Class A based on these key characteristics:

Tile Dimensions (Clause 6.1)

• Note: Overlaps can be adjusted to allow larger batten spacing.

This classification ensures durability and structural performance for roofing tiles as per IS 654.

IS 654: General Quality Requirements for Roofing Tiles

1. Sampling & Defect Criteria (Clause 7.4.1 & Table 3)

• Sample Size & Permissible Defects

• All selected tiles must be checked for:
  • Shape (Clause 5.3)
  • Dimensions & Weight (Clause 6 & 6.3)

2. Classification & Key Properties (Table 1, Clause 8.1)

3. Conformity (Clause 7.5.1)

• A lot conforms if all conditions in Clauses 7.5.2 to 7.5.5 are met.

Summary:

• Use Table 3 for sampling and defect limits.
• Check water absorption and breaking load as per class.
• Ensure dimensional and shape conformity.
• Lot acceptance depends on meeting all specified criteria.

flowchart TD
    A[Select Tiles] --> B[Check Shape, Dimensions, Weight]
    B --> C{Sample Size Based on Lot}
    C --> D[Check Defects ≤ Permissible Limit]
    D --> E{Check Water Absorption & Breaking Load}
    E

IS 654: Dimensions and Tolerances for Mangalore Tiles

1. Tile Sizes (Clause 6.1, Table 2)

Note: Overlaps can be reduced to use smaller tiles for larger batten spacing.

2. Tolerances (Clause 6.2.1, Table 6.2)

• Measurements are done by placing 3 tiles interlocked tightly lengthwise or widthwise on a level surface (Fig. 2).
• Overlaps: Minimum 60 mm (lengthwise), 25 mm (widthwise) (Fig. 1).

3. Measurement & Rounding

• Remove blisters, loose particles before measurement.
• Follow IS 2:1960 for rounding off numerical values.

Summary Diagram (Tile arrangement for tolerance measurement)

flowchart LR
    A[Select 3 Tiles] --> B[Remove defects]
    B --> C[Arrange interlocked on level surface]
    C --> D[Measure overall length/width]
    D --> E[Check if within tolerance limits]

Use these dimensions and tolerances to ensure proper fit and function of Mangalore tiles per IS 654.

IS 654: Sampling & Criteria for Conformity

Sampling (Clause 7.3 & Table 3)

• All selected tiles must be checked for shape (5.3), dimensions (6), and weight (6.3).

Criteria for Conformity (Clause 7.5)

• A lot passes if all conditions in 7.5.2 to 7.5.5 are met.
• Defective tiles in the sample must be ≤ permissible number from Table 3.
• Test results should be rounded as per IS 2:1960, maintaining the same decimal places as specified.

Summary Formula for Acceptance:

[ \text{Lot Accepted if } D \leq D_{max} ]

Where:

• (D) = Number of defective tiles found in sample
• (D_{max}) = Permissible number of defective tiles from Table 3

This ensures quality control by statistically verifying tile conformity before acceptance.

IS 654: Strength Requirements for Roofing Tiles

Key Specifications (Clause 8.1 & Table 1)

Important Notes:

• Breaking load tests: Six samples tested; each must exceed individual minimum, and average must exceed average minimum (Clause 7.5.4).
• Permeability: All tiles must pass permeability tests (Clause 7.5.5).
• Test specimen details for breaking load are in Annex C (Clause 8.3).

Summary:

• Use the above table to verify tile strength.
• Ensure individual breaking load ≥ minimum individual value.
• Ensure average breaking load ≥ minimum average value.
• Water absorption limits ensure durability and weather resistance.

flowchart TD
    A[Tile Sample] --> B{Test Breaking Load}
    B -->|Each ≥ Individual Min| C[Pass Individual Check]
    C --> D{Average of 6 Samples}
    D -->|≥ Average Min| E[Pass Strength Requirement]
    D -->|< Average Min| F[Fail Strength Requirement]
    B -->|< Individual Min| G[Fail Individual Check]

This ensures roofing tiles meet minimum structural strength for safe use.

IS 654: Non-Compliance with Tests - Key Points

• Sampling & Acceptance (Table 3, Clause 7.3):

• Testing Requirements (Clause 7.4.1):
  Tiles must be checked for shape, dimensions, and weight.

• Breaking Load Test (Clause 8.3):
  Tiles must meet breaking load values per Table 1 and Annex C procedures.

• Non-Compliance Protocol (Clause 9):

  • If any tile in the first sample fails, a second sample is tested.
  • If failure occurs again, the entire lot is rejected.

• Rounding Off (Clause 7.4):
  Test results must be rounded per IS 2:1960, matching the significant figures of specified values.

Summary Flow of Non-Compliance Testing

flowchart TD
    A[Select Sample from Lot] --> B{Test Tiles for Shape, Dimensions, Weight, Breaking Load}
    B -->|Pass| C[Lot Accepted]
    B -->|Fail| D[Draw Second Sample]
    D --> E{Test Second Sample}
    E -->|Pass| F[Lot Accepted]
    E -->|Fail| G[Lot Rejected]

This ensures quality control by strict sampling and retesting before rejecting a lot.

IS 654 - Marking of Roofing Tiles

Key Specifications (Clause 10.1 & 10.1.1):

• Marking Content:

  • Manufacturer’s name or trademark
  • Optional: Standard Mark (BIS Mark)

• Marking Area:

  • Shall not exceed 5% of the tile surface area
  • Must be legible and indelible

Purpose of Marking:

• Ensures traceability and quality assurance
• Indicates compliance with IS 654 standard under BIS supervision

Dimensions & Tolerances (Clause 1.10 & 6):

• Typical tile sizes referenced:
  • 420×250 mm, 425×260 mm, 410×235 mm
• Marking size and position must not interfere with tile functionality or aesthetics.

Summary Table for Marking Area Limit:

Additional Notes:

• Use of BIS Standard Mark governed by Bureau of Indian Standards Act, 1986
• Marking must withstand weathering and handling without fading or removal

flowchart LR
    A[Roofing Tile] --> B[Marking]
    B --> C{Content}
    C --> D[Manufacturer Name]
    C --> E[Trademark]
    C --> F[Standard Mark (Optional)]
    B --> G[Max 5% Area]
    B --> H[Legible & Indelible]

This ensures quality control and consumer confidence in roofing tiles conforming to IS 654.

IS 654: Water Absorption Test Method - Key Points

1. Formula for Water Absorption (Clause 3.1, A-3.1):

[ \text{Percentage absorption} = \frac{B - A}{A} \times 100 ]

• A = Weight of dry specimen (g)
• B = Weight after 24 h immersion in cold water (g)

2. Acceptance Criteria (Clause 7.5.3):

• Calculate average ( \bar{X} ) and range ( R ) of test results.
• The value ( \bar{X} + 0.5 R ) must be ≤ limit in Table 1.

3. Test Procedure (Clause 8.1, Annex A):

• Specimens are immersed in cold water for 24 hours.
• Weigh before and after immersion to find absorption.
• Use dry, oven-dried specimens for accuracy.

4. Typical Water Absorption Limits (Table 1, IS 654):

flowchart LR
    A[Dry Specimen Weight (A)] --> B[Immerse in Water 24h]
    B --> C[Wet Specimen Weight (B)]
    C --> D[Calculate % Absorption = ((B - A)/A)*100]
    D --> E[Check if (X + 0.5R) ≤ Limit from Table 1]
    E --> F{Pass/Fail}

Summary:
Use the formula to calculate % absorption after 24h immersion. Ensure ( \bar{X} + 0.5 R ) is within limits specified in Table 1 for compliance.

IS 654: Permeability Test Method for Clay Roofing Tiles

Key Points from Clause 8.2 & Annex B

• Purpose: To check water permeability of tiles as specified by purchaser.
• Test Specimen: Six tiles selected as per Clause 7.5.5.
• Procedure: Detailed in Annex B (Clause 8.2).

Test Procedure (Annex B Summary)

1. Specimen Preparation: Use six tiles, clean and dry.
2. Test Setup:
   • Place tile with surface exposed to water.
   • Apply water under specified pressure or head.
3. Observation: Check for water penetration through tile.
4. Acceptance: No water should pass through tile during test duration.

Water Absorption (Clause 3.2 & Annex A)

• Calculate average % water absorption of six tiles:

  [ \text{Water Absorption %} = \frac{W_{wet} - W_{dry}}{W_{dry}} \times 100 ]

  Where:

  • (W_{dry}) = Dry weight of tile
  • (W_{wet}) = Weight after immersion

Summary Table: Key Specifications

flowchart TD
    A[Select 6 Tiles] --> B[Dry & Weigh Tiles]
    B --> C[Immerse in Water]
    C --> D[Weigh Wet Tiles]
    D --> E[Calculate Water Absorption %]
    A --> F[Set up Permeability Test]
    F --> G[Apply Water Pressure]
    G --> H{Water Penetration?}
    H -- No --> I[Test Passed]
    H -- Yes --> J[Test Failed]

Note: Refer IS 654 Annex B for detailed apparatus and test conditions.

IS 654: Determination of Breaking Load for Roofing Tiles

Key Specifications (Table 1)

• Avg: Average breaking load of six specimens must exceed the average minimum.
• Ind: Each individual specimen breaking load must exceed the individual minimum.

Test Procedure (Annex C, Clause 8.3)

• Use standard test specimens as per Clause C-1.
• Apply load gradually until tile breaks.
• Record breaking load for each specimen.
• Verify all individual values > individual minimum.
• Calculate average of six tests; ensure > average minimum.

Non-Compliance (Clause 9)

• If any tile fails, retest a new sample.
• If failure persists, reject entire lot.

Summary

• Breaking load test ensures tile strength.
• Use Table 1 values for acceptance criteria.
• Follow Annex C for testing procedure.

flowchart TD
    A[Sample 6 Tiles] --> B[Perform Breaking Load Test]
    B --> C{Each Load > Ind. Min?}
    C -- No --> D[Retest New Sample]
    C -- Yes --> E[Calculate Average Load]
    E --> F{Avg Load > Avg Min?}
    F -- Yes --> G[Accept Lot]
    F -- No --> D
    D --> H{Second Sample Pass?}
    H -- No --> I[Reject Lot]
    H -- Yes --> G