Code of Practice for Waterproofing of Roofs with Bitumen Felts

IS 1346 Scope Summary:

• Scope: This standard covers specifications related to bituminous materials and waterproofing treatments for buildings.
• Definitions: Refer to IS 4911:1986 for terms related to bituminous waterproofing and damp-proofing.
• Referenced Standards (Annex A): Essential adjuncts include:
  • IS 702: Industrial bitumen specification
  • IS 1203: Testing bituminous materials - penetration
  • IS 1322: Bitumen felts for waterproofing
  • IS 3067: Practice for damp-proofing design and preparation
  • IS 3384, 4911, 7193: Bitumen primers, glossaries, and felts
  • IS 1609: Laying bitumen felts
  • IS 1834: Hot sealing compounds for concrete joints

Design Considerations (Clause 4.1):
The designer must ensure compliance with IS 3067:1988 for roof design, felt coverings, and finishing details affecting waterproofing.

Key Reference Table (Annex A)

Summary Diagram of Scope Context

graph TD
  A[IS 1346 Scope] --> B[Bituminous Materials]
  A --> C[Waterproofing Treatments]
  B --> D[Industrial Bitumen (IS 702)]
  B --> E[Bitumen Penetration Test (IS 1203)]
  C --> F[Bitumen Felts (IS 1322)]
  C --> G[Damp-proofing Design (IS 3067)]
  C --> H[Primers & Sealants (IS 3384, IS 1834)]
 

IS 1346: Necessary Information & Specifications Summary

1. Reference Standards (Annex A, Clause 2.1):
   Key IS codes to be referred for materials and procedures include:

   • IS 702: Industrial Bitumen specification
   • IS 1322: Bitumen felts for waterproofing
   • IS 3067: General design and preparatory work for damp-proofing
   • IS 1609: Laying damp-proofing treatment using bitumen felts
   • IS 2690 (Parts 1 & 2): Burnt clay flat terracing tiles
   • IS 1237: Cement concrete flooring tiles
   • IS 1834: Hot applied sealing compound for concrete joints

2. Design Information (Clause 4.1):
   Designers must have sufficient info per IS 3067:1988, covering:

   • Roof design details
   • Felt coverings and finishes
   • Waterproofing and damp-proofing requirements

3. Material Quantities (Clause 2.5):

   • Hot applied bitumen: ≥ 2.5 kg/m²
   • Pea-sized gravel/grit: 0.008 m³/m² (coarse sand if gravel unavailable)

Quick Reference Table for Bitumen & Gravel Application

flowchart TD
    A[Roof Design] --> B{Design Info per IS 3067}
    B --> C[Felt Coverings]
    B --> D[Finish Details]
    A --> E[Waterproofing]
    E --> F[Hot Bitumen: ≥2.5 kg/m²]
    E --> G[Gravel/Grit: 0.008 m³/m²]

Summary: Ensure all referenced IS codes are consulted for material specs and design details. Use specified quantities of bitumen and gravel for effective waterproofing as per IS 1346.

IS 1346 - Definitions Summary

• Reference Standard: Definitions in IS 1346 refer primarily to IS 4911:1986 (Glossary of terms related to bituminous waterproofing and damp-proofing).

• Key Terms (from IS 4911:1986):

  • Bitumen Felt: A sheet material made by impregnating or coating a base (hessian, glass fibre, or fibre base) with bitumen.
  • Hot Applied Bitumen: Bitumen heated and applied in molten form.
  • Primer: A preparatory coating applied to surfaces before waterproofing.
  • Grades and Types: Felt types and grades are classified based on base material and finishing (e.g., Type 2 Grade 1 = glass fibre base, self-finished).

• Specifications for Application Layers (Typical):

  Layer	Material	Application Rate
  Primer	IS 3384:1986 compliant	0.27 l/m² min
  Bitumen	Hot applied bitumen	1.2 kg/m² min
  Felt	Hessian-base or glass fibre base	Type 2 or 3, Grade 1 or 2
  Gravel (optional)	Pea-sized gravel/grit	0.006 m³/m²

• Annex A: Lists related IS codes for materials/testing (IS 702, IS 1203, IS 1322, IS 3384, IS 4911, etc.).

Summary Diagram of Typical Waterproofing Layer:

graph TD
    A[Concrete Surface] --> B[Primer (0.27 l/m²)]
    B --> C[Hot Applied Bitumen (1.2 kg/m²)]
    C --> D[Felt Layer (Type 2/3, Grade 1/2)]
    D --> E[Hot Applied Bitumen (1.2 kg/m²)]
    E --> F[Optional Gravel Layer (0.006 m³/m²)]

Note: For detailed definitions, consult IS 4911:1986. IS 1346 relies on these for terminology and classification.

IS 1346: Design Considerations Summary

1. General Design Requirements (Clause 4.1):

   • Designer must refer to IS 3067:1988 for sufficient information on roof design, felt coverings, and finishes.
   • Consider durability, waterproofing, and compatibility with roofing materials.

2. Referenced Standards (Annex A, Clause 2.1):
   Key IS codes for materials and methods related to waterproofing and roofing:

   IS No.	Title
   702:1988	Industrial bitumen specification
   1203:1978	Testing tar & bituminous penetration
   1322:1982	Bitumen felts for waterproofing
   3067:1988	Design & preparatory work for damp-proofing
   3384:1986	Bitumen primer for waterproofing
   1609:1976	Laying damp-proofing with bitumen felts
   2690 (Part 1 & 2):1975	Burnt clay flat terracing tiles

3. Surface Finish (Clause 6.4.1):

   • Surface finish should ensure proper adhesion and protection of waterproofing layers.

Key Design Considerations Checklist:

• Material compatibility: Bitumen, felts, tiles per IS specifications.
• Waterproofing layers: Follow IS 3067 and IS 1609 for detailing.
• Maintenance: Refer to inspection guidelines in Clause 2.1.
• Durability: Use industrial bitumen per IS 702.
• Surface preparation: Clean, dry, and smooth as per Clause 6.4.1.

Typical Design Formula (from IS 3067/related codes):

[ \text{Minimum slope for roof} = 1:100 \quad \text{to ensure drainage} ]

flowchart TD
    A[Design Requirements] --> B[Material Selection]
    B --> C[Waterproofing Layers]
    C --> D[Surface Finish]
    D --> E[Inspection & Maintenance]

Note: For detailed design, consult IS 3067:1988 and related standards listed in Annex A of IS 1346.

IS 1346 - Materials for Waterproofing: Key Specifications

• Bitumen Grades (IS 702:1988):

  • Industrial blown bitumen Grade 85/25 or 90/15 for bonding between felts and roof.
  • For top dressing, bitumen with penetration ≤ 40 (IS 1203:1978).
  • Vertical surfaces:
    • Up to 1 m height: Grade 85/25 or 90/15.
    • Above 1 m height: Grade 115/15.

• Bitumen Application Rates:

  • Hot applied bitumen: 1.2 kg/m² minimum between layers.
  • For final layer: 2.5 kg/m² minimum (Clause 2.5).

• Felt Types:

  • Hessian-base self-finished felt: Type 3, Grade 1.
  • Glass fibre base bitumen felt: Type 2, Grade 1.
  • Fibre-base self-finished felt: Type 2, Grade 1 or Grade 2.

• Top Dressing:

  • Pea-sized gravel or grit (free of fine sand) at 0.006 to 0.008 m³/m².
  • Coarse sand allowed if gravel unavailable.

• Primer:

  • IS 3384:1986 compliant primer at 0.27 l/m² minimum.

Summary Table:

flowchart TD
    A[Roof Surface]

IS 1346 Waterproofing Treatment - Key Specifications & Formulas

1. Types of Waterproofing Treatments

2. Timber Roof Treatment (Clause 1.2)

• Hot applied bitumen @ 1.2 kg/m² min
• Two coats of bituminous paint @ 0.1 l/m² per coat
  OR
• Single coat of bituminous emulsion @ 0.5 l/m²

3. General Notes

• Bitumen application rates are minimum.
• Gravel or grit must be pea-sized and free from fine sand.
• Primer conforms to IS 3384:1986.
• Felt types and grades are specified for durability and adhesion

IS 1346: Method of Laying Waterproofing Treatment

Key Specifications & Layers (per m²)

IS 1346: Inspection and Maintenance - Key Points

1. Sequence of Operation for Roof Maintenance (Clause 7.1)

• Preparatory work as per IS 3067:1988 (damp-proofing details)
• Collect & store materials/tools
• Clean roof surface (remove foreign matter)
• Treat gutters and drain mouths
• Treat main roof (flat or sloping)
• Treat flashings and projecting pipes
• Apply top dressing: gravel, grit, tiles, concrete protection, or paints/emulsion
• Clean and remove surplus materials

2. Material Specifications (Clause 2.5)

• Hot applied bitumen: Minimum 2.5 kg/m²
• Pea-sized gravel or grit (free from fine sand): 0.008 m³/m²
  • Note: Coarse sand can substitute if pea gravel unavailable.

3. Referenced IS Codes for Materials & Methods

Summary Table: Bitumen & Gravel Application

flowchart TD
    A[Start: Roof Inspection] --> B[Clean Roof Surface]
    B --> C[Treat Gutters & Drains]
    C --> D[Treat Main Roof Surface]
    D --> E[Treat Flashings & Pipes]
    E --> F[Apply Bitumen & Gravel]
    F --> G[Top Dressing: Tiles/Concrete/Paint]
    G --> H[Clean & Remove Surplus Materials]
    H --> I[End: Maintenance Complete]

For detailed

IS 1346: List of Referred Indian Standards (Annex A, Clause 2.1)

This standard refers to key IS codes related to waterproofing, bitumen, tiles, and damp-proofing materials:

Usage Notes:

• These standards complement IS 1346 for comprehensive waterproofing design and materials testing.
• Refer to each IS for detailed specifications, testing methods, and application guidelines.

flowchart TD
    A[IS 1346] --> B[Bitumen Specifications (IS 702, 1203)]
    A --> C[Waterproofing Felts (IS 1322, 1609)]
    A --> D[Tiles & Flooring (IS 1237, 2690)]
    A --> E[Damp-proofing Codes (IS 3067, 3384)]
    A --> F[Sealing Compounds (IS 1834)]
    A --> G[Glossary & Terminology (IS 4911)]

This diagram shows the relation of IS 1346 with referred standards for waterproofing and roofing materials.