What is the recommended thickness for basement waterproofing (tanking)?

A minimum of 25 mm, applied in two separate layers (Clause 6.2.1).

What is the correct application temperature for bitumen mastic?

The mastic should be heated to a uniform temperature between 175°C and 200°C (Clause 5.1).

Can bitumen mastic be applied on a damp surface?

No, the code explicitly states the surface shall be thoroughly dry, clean, and free of dust before application (Clause 4.1).

What materials are used to make the bitumen mastic?

The mastic is composed of a bitumen binder (conforming to IS 73 or IS 702) and a fine aggregate/filler, typically limestone (Clause 3 and Table 1).

IS 7198

: 1974

Code of practice for damp-proofing using bitumen mastic

CurrentSpecializedCode of PracticeMaterials Science · Waterproofing and Damp-Proofing

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This code of practice covers the use of bitumen mastic for damp-proofing and waterproofing courses in building construction. It details the required properties of materials, methods for surface preparation, techniques for application, and the specified thickness for various locations like basements, floors, and roofs.

Code of practice for damp-proofing using bitumen mastic

Quick Reference Values

Application temperature of mastic175 to 200 °C

Minimum thickness for basement tanking (two coats)25 mm

Minimum thickness for general flooring (single coat)10 mm

Minimum thickness for roofing (two coats)20 mm

Binder content in mastic (by mass)14 to 18 percent

Hardness number (at 25°C)30 to 70

Practical Notes

Surface preparation is critical; the substrate must be clean, dry, and free from any loose material to ensure proper adhesion of the mastic.

Maintaining the correct application temperature (175-200°C) is essential for workability and to achieve a uniform, void-free layer.

Adequate ventilation is mandatory during application due to the emission of fumes from hot bitumen mastic.