Code of practice for laying damp-proofing treatment using bitumen felts

IS 1609: Scope Summary & Key Specifications

Scope (Clause 2.1)

• Covers execution of damp-proofing using bitumen felts for foundations, walls, and basements.
• Focuses on application procedures, not material specifications (covered under IS 1322, IS 7193).
• Complements other standards listed in Annex A (e.g., IS 3067 for design, IS 1346 for roofing).

Key Specifications for Felt Laying (Clause 7.3)

Relevant IS Codes in Annex A (Clause 2.1)

Summary Diagram: Felt Laying Process

flowchart TD
    A[Surface Preparation] --> B[Cement Rendering & Corner Fillets Set]
    B --> C[Primer Coat Applied]
    C --> D[Felt Rolled Up]
    D --> E[Start Laying on Floor]
    E --> F[Pour Hot Bonding Material]
    F --> G[Unroll Felt with Pressure]
    G --> H[Cover Entire Floor]
    H --> I[Overlap Joints ≥ 100mm]
    I --> J[Laying Felt on Walls]
    J --> K[Unroll Felt Upward with Hot Bitumen]
    K --> L[Break Joints in Subsequent Layers]

Note: This code prioritizes

IS 1609: Referenced Standards Summary

Clause 2.1 & Annex A specify that IS 1609 relies on several key Indian Standards (IS) as adjuncts for materials and practices related to bitumen felt damp-proofing:

Key Notes on Application (Clause 7.3)

• Felt is laid on a prepared surface with primer and cement rendering.
• Hot bitumen is poured in front of the unrolled felt to bond it.
• Overlapping joints must be minimum 100 mm.
• Subsequent felt layers' joints should break midway between joints of the layer beneath.

Practical Tips

• Follow IS 1346:1991 for roofing details.
• Use IS 1322:1982 and IS 7193:1974 for selecting bitumen felt materials.
• Primer application per IS 3384:1986 is critical for bonding.
• IS 3067:1988 guides design and preparatory work.

flowchart TD
    A[Surface Preparation] --> B[Primer Application]
    B --> C[Roll Felt Placement]
    C --> D[Pour Hot Bitumen]
    D --> E[Unroll Felt with Pressure]
    E --> F[Seal Overlaps ≥ 100mm]
    F --> G[Apply Subsequent Layers with Staggered Joints]

This framework ensures compliance with IS 1609 and related standards for durable damp-proofing using bitumen felts.

IS 1609: Definitions & Key Specifications for Bitumen Felt Damp-Proofing

• Bitumen Felt: A waterproofing material made of bitumen impregnated felt, used for damp-proofing foundations, walls, and basements (Ref: IS 1322:1982, IS 7193:1974).

• Primer: A bitumen primer applied on prepared surfaces to enhance adhesion (Ref: IS 3384:1986).

• Laying Method (Clause 7.3):

  • Surface must be prepared, cement rendering and fillets set, and primer applied.
  • Felt is rolled out on the floor with hot bitumen bonding poured ahead.
  • Overlaps must be minimum 100 mm.
  • Subsequent felt layers should have joints staggered (break joint).

• Related Standards (Annex A):

  IS No.	Title
  1322:1982	Bitumen felts for waterproofing and damp-proofing
  3384:1986	Bitumen primer for waterproofing and damp-proofing
  3067:1988	Design details for damp-proofing and waterproofing
  1346:1991	Waterproofing of roofs with bitumen felts

Summary Table: Overlapping Joints

This ensures continuity and effectiveness of damp-proofing layers.

flowchart LR
    A[Surface Preparation] --> B[Cement Rendering & Fillets Set]
    B --> C[Apply Bitumen Primer]
    C --> D[Roll out Felt on Floor]
    D --> E[Pour Hot Bitumen Bonding]
    E --> F[Unroll Felt with Pressure]
    F --> G[Seal Overlapping Joints (≥100mm)]
    G --> H[Lay Felt on Wall Verticals]
    H --> I[Stagger Joints in Next Layers]

This concise framework from IS 1609 guides proper execution of bitumen felt damp-proofing.

IS 1609: Necessary Information Summary

1. Reference Standards (Annex A, Clause 2.1)

IS 1609 refers to several essential IS codes for materials and procedures:

2. Laying of Felt (Clause 7.3 Key Points)

• Felt laid after surface preparation, cement rendering, corner fillets set, and primer applied.
• Start laying on floor, complete before wall treatment.
• Hot bitumen poured ahead of felt roll, unrolled with pressure to squeeze excess bitumen.
• Overlaps minimum 100 mm at sides and ends.
• Subsequent layers stagger joints to break alignment.

3. Designer's Responsibility (Clause 4)

• Designer must ensure all necessary info as per IS 3067:1988 is available before specifying damp-proofing.

Quick Checklist for Designers:

• Confirm material specs from referenced IS codes.
• Ensure surface preparation and primer application.
• Follow felt laying sequence with hot bitumen bonding.
• Maintain minimum 100 mm overlaps.
• Stagger joints in multi-layer systems.
• Refer IS 3067 for design details and preparatory work.

flowchart TD
    A[Surface Preparation] --> B[Cement Rendering & Corner Fillets Set]
    B --> C[Primer Coat Applied]
    C --> D[Felt Roll Prepared & Rolled Up]
    D --> E[Start Laying on Floor]
    E --> F[Pour Hot Bitumen Ahead]
    F --> G[Unroll Felt with Pressure]
    G --> H[Seal Overlaps ≥ 100 mm]
    H --> I[Lay Felt on Walls Similarly]
    I --> J[Subsequent

IS 1609: Key Materials Specifications for Damp-Proofing

1. Bitumen Bonding Material (Clause 5.4)

• Use blown bitumen conforming to IS 702:1988.
• Recommended grades: 85/25 or 90/15 (penetration grades indicating hardness).

2. Bitumen Felt (Clause 6.1)

• Types and grades as per:
  • IS 1322:1982 (Bitumen felts for waterproofing and damp-proofing)
  • IS 7193:1974 (Glass fibre base coal tar pitch and bitumen felts)

3. Laying of Bitumen Felt (Clause 7.3)

• Surface preparation: clean, cement rendered, primer applied.
• Felt rolled up, laid on floor first.
• Hot bitumen poured ahead of felt roll; felt unrolled with pressure to squeeze excess bitumen.
• Overlaps: minimum 100 mm on sides and ends.
• Subsequent layers staggered to break joints.

4. Referenced Indian Standards (Annex A)

Summary Table: Bitumen Grades

flowchart LR
  A[Surface Preparation] --> B[Apply Primer]
  B --> C[Roll up Bitumen Felt]
  C --> D[Pour Hot Bitumen on Floor]
  D --> E[Unroll Felt with Pressure]
  E --> F[Overlap Joints ≥ 100mm]
  F --> G[Lay Felt on Walls similarly]

This ensures proper bonding and waterproofing per IS 1609 guidelines.

IS 1609: Damp-Proofing Treatment Key Points

1. Materials (Clause 5.1)

• Surface preparation: Cement-sand mortar (1:4)
• Cement: IS 269:1989
• Sand: IS 2116:1980, free from deleterious matter

2. Damp-Proofing Above Ground Level (Clause 6.2)

• Bituminous primer: 0.2 to 0.4 l/m², brushed and dried before treatment
• Ensure continuous, overlap joints properly made (Clause 7.1)

3. Damp-Proofing Below Ground Level - Basements (Clause 6.3)

Normal Treatment (Two Layers of Felt):

• Note: Fibre-based self-finished felt is not recommended for basements.

Summary Diagram

flowchart TD
    A[Surface Preparation: Cement-Sand Mortar (1:4)] --> B[Bituminous Primer (0.2-0.4 l/m²)]
    B --> C[Damp-Proofing Treatment Above Ground]
    B --> D[Basement Treatment]
    D --> E[Primer (0.27 l/m²)]
    E --> F[Hot Bitumen (1.5 kg/m²)]
    F --> G[Felt Layer 1 (Hessian/Glass Fibre)]
    G --> H[Hot Bitumen (1.5 kg/m²)]
    H --> I[Felt Layer 2 (Hessian/Glass Fibre)]

This ensures an effective continuous barrier against water penetration as per IS 160

IS 1609: Method of Laying Damp-Proofing Treatment

Key Specifications & Rates

Method Summary

• Surface Preparation: Cement-sand mortar (1:4) as per IS 269 & IS 2116.
• Primer: Applied on vertical faces only, 0.27 l/m², allowed to dry.
• Bitumen Application: Hot applied blown bitumen at 1.5 kg/m² per layer.
• Felt Layers: Alternate layers of felt and bitumen, starting and ending with bitumen.
• Basement Note: Fibre-based felt not recommended below ground.

Layer Sequence Example (Heavy Treatment)

graph TD
    A[Primer (Vertical Faces) - 0.27 l/m²] --> B[Bitumen - 1.5 kg/m²]
    B --> C[Felt Layer 1]
    C --> D[Bitumen - 1.5 kg/m²]
    D --> E[Felt Layer 2]
    E --> F[Bitumen - 1.5 kg/m²]
    F --> G[Felt Layer 3]
    G --> H[Bitumen - 1.5 kg/m²]

Note: Always ensure proper drying time for primer and uniform heating of bitumen for effective bonding.

IS 1609 - Site Preparation for Damp-Proofing Treatment

Key Points from Clause 7.2 (Site Preparation)

• Keep site free of water by continuous pumping until work and structural protection for damp-proofing are complete.
• Dry surface is crucial for good adhesion of bitumen; use suitable drying methods.
• If surface remains damp, the first hot bitumen coat may not stick, but adhesion is ensured by the first felt layer.
• Walls should be kept dry to ensure bitumen and felt adhere properly.

Bitumen Specifications (Clause 5.4)

• Use blown bitumen as per IS 702:1988.
• Recommended grades: 85/25 or 90/15.

Damp-Proofing Treatment (Clause 6)

• Primer is applied only on vertical faces.
• Bitumen is applied hot at 1.5 kg/m² per layer.
• Felt layers alternate with bitumen layers.

Method Summary for Damp-Proofing (Clause 6.2)

• Apply bituminous primer (0.2 to 0.4 l/m²) and allow to dry before bitumen layers.
• Ensure overlapping joints are well stuck for watertightness.

flowchart TD
    A[Site Preparation] --> B[Keep site dry by pumping]
    B --> C{Surface condition}
    C -->|Dry| D[Apply bitumen primer & layers]
    C -->|Damp| E[First bitumen may not stick]
    E --> F[Ensure felt adheres to bitumen]
    D --> G[Apply felt layers alternated with bitumen

IS 1609: List of Referred Indian Standards for Damp-Proofing Using Bitumen Felts

Key Notes:

• IS 1322 & IS 7193 specify types and grades of bitumen felts.
• IS 1346 guides waterproofing of roofs using bitumen felts.
• IS 3067 covers general design details and preparatory work for damp-proofing and waterproofing.
• These standards ensure harmonization with international practices and address material specifications, surface preparation, application, and quality control.

Summary Diagram of Reference Flow

graph LR
A[IS 1609 - Execution of Bitumen Felt] --> B(IS 1322 & IS 7193 - Material Specs)
A --> C(IS 3067 - Design & Prep)
A --> D(IS 1346 - Roof Waterproofing)
A --> E(IS 269 - Cement)
A --> F(IS 702 - Bitumen)
A --> G(IS 2116 - Sand for Mortars)
A --> H(IS 3384 - Bitumen Primer)
A --> I(IS 4911 - Glossary)
A --> J(IS 7193 - Glass Fibre Felts)