Code of practice for painting asbestos cement building products

IS 3140 - Scope Summary & Key Points

• Scope: Covers specifications for asbestos cement sheets, including definitions (per IS 1303-1958) and painting requirements.
• Definitions: Refer IS 1303-1958 for terms related to asbestos cement sheets.
• Back Painting: Coating the back and edges with paint to prevent moisture ingress.
• Painting (Clause 7.1):
  • Sheets must be dry before painting.
  • Use paint compatible with primer.
  • Follow painting schedules as per BIS guidelines (Code of Practice for Painting).
• Contact Information: Regional and branch offices of BIS for further standards and clarifications.

Important Notes:

Diagram: Painting Process Flow

flowchart TD
    A[Asbestos Cement Sheet] --> B{Is sheet dry?}
    B -- No --> C[Dry sheet thoroughly]
    B -- Yes --> D[Apply primer]
    D --> E[Apply compatible paint]
    E --> F[Back painting on edges & back]
    F --> G[Finished sheet ready for use]

For detailed painting schedules and specifications, consult the BIS Code of Practice for Painting and IS 3140 full text.

IS 3140 - Definitions Summary

• Reference Standards: Definitions primarily follow IS 1303-1958.

• Back Painting (Clause 2.2):
  Coating the back and edges of asbestos sheets with paint to prevent moisture ingress.

• Painting Specifications (Clause 7.1):

  • Sheets must be thoroughly dry before painting.
  • Use any painting system compatible with the applied primer.
  • Follow the "Code of Practice for Painting" (published separately).

Key Points:

Additional Notes:

• For detailed painting schedules and primer compatibility, refer to the BIS "Code of Practice for Painting" and IS 1303.

• Contact BIS regional offices for standards and clarifications.

flowchart LR
    A[Asbestos Sheet] --> B{Dry?}
    B -- No --> C[Dry Sheet]
    C --> B
    B -- Yes --> D[Apply Primer]
    D --> E[Apply Paint (Compatible)]
    E --> F[Back Painting (Back & Edges)]
    F --> G[Finished Sheet]

This flow ensures moisture protection and durability as per IS 3140.

IS 3140 — Necessary Information & Specifications for Painting Asbestos Cement Products

Key Points from IS 3140:

• Back Painting (Clause 2.2):
  Paint the back and edges of sheets to prevent moisture ingress.

• Painting Conditions (Clause 7.1):

  • Sheets must be thoroughly dry before painting.
  • Use paint systems compatible with the primer.
  • Refer to IS 2395 (Part II) for paint system recommendations on old surfaces.

• Information to be Furnished (Clause 3.1):
  Provide details on:

  • Location of use (roof, side-cladding, interior).
  • Exposure to corrosive atmosphere.
  • Weathering extent of asbestos cement.
  • Purpose of painting (aesthetic, protective, or both).

• Surface Preparation (Clause 5.3.1):

  • Remove flaking, bleached, or saponified paint.
  • Clean by scraping, sanding, washing, and drying.
  • Roughen glossy surfaces for better adhesion.

Summary Table: Necessary Information for Painting

Additional Notes:

• Use compatible primers and paints as per IS 2395 (Part II).
• Back painting is crucial for moisture protection.
• Proper surface prep ensures durability and adhesion.

flowchart TD
    A[Start: Paint Planning] --> B[Gather Info: Location, Exposure, Weathering, Purpose]
    B --> C[Surface Preparation: Remove loose paint, clean, dry]
    C --> D[Select Paint System: Compatible with primer & exposure]
    D --> E[Back Paint Sheets & Edges]
    E --> F[Apply Finish Coats]
    F --> G[Inspection & Maintenance]

References:

• IS 3140: Painting of Asbestos Cement Products
• IS 2395 (Part II): Code of Practice for Painting (Calcareous Surfaces)

IS 3140: Characteristics of Substrata and Treatment for Asbestos Cement Painting

Key Points from IS 3140:

• Substrate Situations (Clause 3.1):

  • Identify location: roof, side-cladding, internal, pipes, gutters (interior/exterior).
  • Assess exposure to corrosive atmosphere.
  • Note weathering extent of asbestos cement.
  • Define painting purpose: aesthetic, protective, or both.

• Surface Suction (Clause 5.2):

  • For high/variable suction surfaces, apply pretreatment (see Clause 4.2).
  • Pretreatment ensures uniform paint absorption.

• Back Painting (Clause 2.2):

  • Paint backs and edges to prevent moisture ingress.

• Fungus Treatment (Clause 4.3):

  • Remove fungus by scraping, rubbing with glass wool/sandpaper.
  • Wash with clean water, dry thoroughly.
  • Apply two coats of fungicidal wash; do not wash off before painting.
  • Brush surface after 24 hours to remove dust.

Additional Notes:

• Use fungicidal washes as per IS 2395 (Part I).
• Paint specifications: ready-mixed, lead-free, acid/alkali/water/heat resistant.
• Follow published Code of Practice for Painting Calcareous Surfaces for detailed schedules.

Summary Table: Surface Treatment Steps

flowchart TD
    A[Identify Substrate & Exposure] --> B{Surface Suction?}
    B -- High/Variable --> C[Pretreatment]
    B -- Low --> D[Back Painting]
    C --> D
   

IS 3140: Preparation of Surface for Painting - Key Points

Surface Preparation (Clauses 5.1, 5.2, 4.3)

• Cleaning:

  • Rub surface with sandpaper; roughen glazed areas.
  • Brush off loose powdery material.
  • Avoid wire brushes to prevent iron stains.

• Fungus Treatment (Clause 4.3):

  1. Scrape and rub with glass wool + sandpaper.
  2. Wash with clean water; dry thoroughly.
  3. Apply 2 coats of fungicidal wash; allow to dry between coats.
  4. Paint directly over fungicidal wash without washing it off.

• High or Variable Suction Surfaces (Clause 5.2):

  • Use pretreatment as per Clause 4.2 (usually a primer or sealer to regulate suction).

• Dust Removal:

  • After washing, brush with soft bristle brush after 24 hours to remove dust.

Additional Notes

• For previously painted surfaces, follow detailed preparation steps (Clauses 5.3.1 to 5.3.4).
• Use ready mixed paints as per IS specifications (e.g., IS 361 for light stone color).

Summary Table

flowchart TD
    A[Surface] --> B[Clean with Sandpaper]
    B --> C{Fungus Present?}
    C -- Yes --> D[Scrape & Sandpaper]
    D --> E[Wash & Dry]
    E --> F[Apply Fungicidal Wash (2 coats)]
    F --> G[Paint over Fungicidal Wash]
    C -- No --> H{High Suction?}
    H -- Yes --> I[Pretreatment (Primer/Sealer)]
   

IS 3140 - Back Painting: Key Points & Specifications

• Purpose (Clause 2.2):
  Back painting prevents moisture ingress by coating the back and edges of sheets.

• When to Back Paint (Clauses 4.4.1.2 & 6.1):
  Mandatory if an impervious paint system is used on the face.

• Materials for Back Painting (Clause 6.1):
  Use at least one coat of:

  • Alkali-resistant primer
  • Bitumen paint
  • Colourless waterproofer

• Application Notes (Clause 6.1):

  • Avoid contamination of the face with bitumen or waterproofer to prevent discoloration or drying issues.
  • Preferably, back painting is done after face painting; if not possible, do it before fixing sheets.

• Repainting Old Surfaces (Clause 5.3.5):
  If old paint is sound, apply 1-2 coats of finishing paint only.

Summary Table:

This ensures durability and moisture protection of painted sheets per IS 3140.

IS 3140 - Painting of Asbestos Sheets: Key Points & Specifications

1. Surface Preparation & Dryness

• Sheets must be thoroughly dry before painting (Clause 7.1).
• If old paint film is sound, apply 1-2 coats of finishing paint after surface prep (Clause 5.3.5).

2. Back Painting

• Back painting (Clause 2.2): Coat back and edges to prevent moisture ingress.

3. Paint Selection

• Use paints compatible with the primer applied (Clause 4.4).
• Follow painting schedules as per BIS "Code of Practice for Painting" (now published).

4. Painting System

• Any system compatible with primer and finish requirements may be adopted (Clause 7.1).

Typical Painting Schedule (Example for Calcareous Surfaces from BIS Part II)

Contact for BIS Painting Code & Support

• Regional & Branch offices listed in Clause 7.1 for detailed schedules and standards.

flowchart TD
    A[Dry Asbestos Sheet] --> B[Apply Primer]
    B --> C{Old Paint Sound?}
    C -- Yes --> D[Apply 1-2 Finishing Coats]
    C -- No --> E[Apply Undercoat + Finishing Coats]
    E --> F[Back Paint Edges & Back]
    D --> F

Summary: Ensure dry sheets, use compatible paints, back paint edges, and follow BIS painting schedules for durability and moisture protection.

IS 3140 Key Points on Selection of Paints

• Clause 4.4 & 4.1.2:

  • Paint selection must consider alkali resistance.
  • Use alkali-resistant paints or apply at least two coats of alkali-resistant primer to protect non-resistant paints.
  • Primer must form an impervious barrier to alkali.
  • Refer IS 2395 (Part II) for detailed paint system selection.

• Clause 7.1:

  • Asbestos sheets must be thoroughly dry before painting.
  • Paint systems must be compatible with the primer used.
  • Back painting (Clause 2.2) is recommended to prevent moisture ingress.

• Additional Notes:

  • For calcareous surfaces, consult the "Code of Practice for Calcareous Surfaces: Part II Painting Schedules" (published).
  • Glossary and detailed painting schedules available from BIS offices.

Paint System Selection Summary (per IS 3140 & IS 2395)

Contact for Paint Codes & Schedules

BIS Regional Offices (e.g., Western - Mumbai: 6 32 92 95) provide detailed schedules and codes for paints.

flowchart TD
    A[Start: Surface Type] --> B{Is surface alkali-prone?}
    B -- Yes --> C[Apply alkali-resistant primer (2 coats)]
    B -- No --> D[Select primer as per surface type]
    C --> E[Apply compatible finish coats]
    D --> E
    E --> F{Is surface calcareous?}
    F -- Yes --> G[Refer Calcareous Painting Schedule (IS Code)]
    F -- No --> H[Finish painting]

Summary: Ensure dryness, use alkali-resistant primers for alkali surfaces, follow IS 239

IS 3140: Fungicidal Treatment Key Points

Fungicidal Treatment Procedure (Clause 4.3)

• Surface Preparation:
  • Scrape and rub down with glass wool and sandpaper.
  • Wash thoroughly with clean water; allow drying.
• Application:
  • Apply first coat of fungicidal wash; allow it to dry.
  • Apply a second coat; let it dry thoroughly.
• Painting:
  • Paint over fungicidal wash without washing it off.
  • Use specified paints (e.g., Indian Standard Colour No. 361, light stone, or bituminous black lead-free paint).

Important Specifications

• No burning or blow lamp drying (Clause 5.3.2) to avoid cracking.
• Back Painting (Clause 2.2) to prevent moisture ingress.
• Dry Sheets (Clause 7.1) mandatory before painting.

Summary Table: Fungicidal Treatment Steps

Reference Standards

• IS 2395 (Part I) for fungicidal wash specifications.
• Painting schedules under preparation (now published) for calcareous surfaces.

flowchart TD
    A[Surface with Fungus] --> B[Scrape & Rub Down]
    B --> C[Wash with Clean Water]
    C --> D[Dry Surface]
    D --> E[Apply Fungicidal Wash - 1st Coat]
    E --> F[Dry]
    F --> G[Apply Fungicidal Wash - 2nd Coat]
    G --> H[Dry Thoroughly]
    H --> I[Paint Over Fungicidal Wash]
    I --> J[Back Paint Edges & Back]

For detailed paint types and procurement

IS 3140: Weathering & Alkali Attack Key Points

• Alkali Attack Risk: New asbestos cement sheets are alkaline (due to Portland cement), which can degrade oil paints.

• Weathering (Clause 4.1.1):

  • Allow sheets to weather for several months.
  • Alkalis carbonate on air exposure and are partly washed off by rain.
  • Weathering reduces alkali but may cause powdery surfaces, needing cleaning before painting.

• Paint System (Clause 4.1.2 & 4.4.3):

  • Use alkali-resistant paints or at least two coats of alkali-resistant primer forming an impervious barrier.
  • For external sheeting, paints can be:
    • (a) Porous alkali-resistant
    • (b) Impervious alkali-resistant with back painting
  • Refer IS 2395 (Part II) for detailed paint schedules.

Summary Table: Alkali Attack Prevention

flowchart LR
    A[New Asbestos Cement Sheet] --> B[Weathering for Months]
    B --> C[Alkalis Carbonate & Wash Off]
    C --> D[Surface Cleaning]
    D --> E[Apply Alkali-Resistant Primer (2 coats)]
    E --> F[Apply Alkali-Resistant Paint (per IS 2395)]
    F --> G[Durable Finish with Alkali Protection]

Note: Proper weathering and paint selection are crucial to prevent alkali attack and ensure long-term durability.

IS 3140 - Painting Previously Painted Surfaces: Key Points

Surface Preparation (Clauses 5.3.1 to 5.3.5)

• Remove defective paint: Flaking, bleaching, or saponified paint must be removed.
• Cleaning: Scrape, sandpaper, wash, and dry thoroughly.
• Roughening: Glossy old surfaces must be roughened for adhesion.
• Paint compatibility: Follow IS 2395 (Part II) for selecting paint systems compatible with existing finishes.
• Coats: If old paint is sound, apply 1-2 coats of finishing paint.

Back Painting (Clause 7.1)

• Asbestos sheets must be dry before painting.
• Use paint systems compatible with the primer.

Summary Table for Previously Painted Surfaces

Additional Notes

• Drying: Ensure complete drying after cleaning.
• Adhesion: Roughening improves paint bond.
• Compatibility: Essential to avoid peeling or blistering.

flowchart TD
    A[Previously Painted Surface] --> B{Defective Paint?}
    B -- Yes --> C[Remove defective paint]
    B -- No --> D[Check paint soundness]
    C --> E[Clean & Dry Surface]
    D --> E
    E --> F{Glossy Surface?}
    F -- Yes --> G[Roughen Surface]
    F -- No --> H[Proceed]
    G --> H
    H --> I[Select Paint System (IS 2395 Part II)]
    I --> J{Old Paint Sound?}
    J -- Yes

IS 3140 Key Specifications for Waterproofing Gutters and Downpipes

• Waterproof Coating Inside Gutters & Pipes (Clause 4.4.4):

  • Apply a bitumen waterproof coating on the inside (water-carrying surface) of asbestos cement gutters and downpipes before erection.
  • Outer surface: Use alkali-resistant porous paint to allow breathing, reducing blistering/flaking.

• Back Painting (Clauses 2.2 & 6.1):

  • Protect back and edges of sheets with at least one coat of:
    • Alkali-resistant primer, or
    • Bitumen paint, or
    • Colourless waterproofer.
  • Avoid contamination of the face with bitumen or waterproofer to prevent discoloration or paint drying issues.
  • Back painting is preferably done after face painting, but often before fixing.

Summary Table for Painting Sequence

flowchart TD
    A[Asbestos Cement Gutters/Downpipes] --> B[Inside Surface]
    A --> C[Outer Surface]
    A --> D[Back & Edges]

    B --> E[Bitumen Waterproof Coating (Before erection)]
    C --> F[Alkali-resistant Porous Paint (After waterproofing)]
    D --> G[Alkali-resistant Primer/Bitumen/Waterproofer (Before/After face painting)]

Note: Ensure careful application to avoid contamination between coatings for durability and aesthetic quality.

IS 3140: Precautions & Limitations Summary

1. Back Painting (Clause 2.2)

• Paint the back and edges of asbestos sheets to prevent moisture ingress.
• Use specified paint compatible with sheet material.

2. Painting Requirements (Clause 7.1)

• Sheets must be thoroughly dry before painting.
• Use painting systems compatible with the primer.
• Refer to the Code of Practice for Painting for detailed schedules (now published).

3. General Precautions

• Avoid moisture entry to maintain durability.
• Use compatible primers and paints.
• Ensure proper drying to prevent paint failure.

Quick Reference Table: Painting Precautions

Additional Notes:

• Follow definitions as per IS 1303-1958.
• For detailed painting schedules, consult the BIS Code of Practice for Painting (Calcareous Surfaces, Part II).
• Contact regional BIS offices for standards and clarifications.

flowchart TD
    A[Asbestos Sheet] --> B[Dry Sheet Completely]
    B --> C[Back & Edge Painting]
    C --> D[Apply Compatible Primer]
    D --> E[Finish Painting]
    E --> F[Moisture Protection Ensured]

This ensures longevity and performance of asbestos sheets per IS 3140.

IS 3140 References to Other Standards – Key Points

• Primary Reference:

  • IS 1303-1958 for definitions related to asbestos cement products.

• Painting Practice:

  • Clause 7.1 specifies painting on thoroughly dry asbestos sheets.
  • Compatible painting systems with primers as per the finish requirements.
  • Reference to the Code of Practice for Painting (Part II: Painting Schedules) by BIS (published after IS 3140).

• Other Relevant IS Codes:

  • IS 1303 for asbestos cement products definitions.
  • BIS Code of Practice for Painting (for detailed painting schedules and materials).

• Contact for Standards & Publications:

  • BIS Regional and Branch offices across India (e.g., Bombay, Calcutta, Chandigarh, Madras).
  • Sales offices and inspection points listed for acquiring standards and clarifications.

Summary Table: Key References

Additional Notes for Engineers:

• Always ensure asbestos sheets are dry before painting.
• Use primers compatible with the selected paint system.
• Check the latest BIS painting code for updated schedules and materials.
• Consult IS 1303 for material properties and terminology.

flowchart LR
    A[IS 3140 - Asbestos Cement Products] --> B[IS 1303 - Definitions]
    A --> C[BIS Code of Practice for Painting]
    C --> D[Painting Schedules & Materials]
    B --> E[Material Properties]
    A --> F[BIS Offices for Standards & Support]

This structure ensures compliance and quality in finishing asbestos cement products.

IS 3140 primarily addresses Right to Information (RTI) and Copyright in the context of public safety standards dissemination.

Key Points:

• Right to Information (RTI):

  • Ensures public access to information held by public authorities.
  • Promotes transparency and accountability in government and public bodies.
  • The standard is made publicly available to aid education, knowledge, and disadvantaged communities.

• Copyright Protection:

  • The publication is protected by copyright.
  • Unauthorized reproduction or distribution is prohibited.
  • Use is allowed only for personal, educational, or non-commercial purposes with proper acknowledgment.

No structural formulas or tables are specified under these clauses, as IS 3140 focuses on legal and informational guidelines rather than engineering design.

If you need structural design formulas or tables, please specify the relevant IS code (e.g., IS 456 for concrete design).