What is the primary use of this material?

It is used for providing an impermeable waterproofing layer on roofs, basements, and damp-proofing courses.

Can the mastic be heated over an open flame?

No, it must be heated in a mechanically agitated cooker to ensure uniform heating and prevent burning of the bitumen.

What type of aggregates are used in roofing mastic?

Graded limestone or siliceous material, which is free from dust, clay, and organic matter.

IS 3698 Part 1

: 1991

Bitumen mastic for roofing and waterproofing - Part 1: General requirements

CurrentSpecializedSpecificationMaterials Science · Roofing Materials

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This standard lays down the general requirements for bitumen mastic used in roofing and waterproofing, specifying material composition, physical properties, and conformity testing for durability against water ingress.

Specifies general requirements for bitumen mastic used for roofing and waterproofing.

Quick Reference Values

maximum heating temperature200°C

hardness number testing temperature25°C

typical thickness per layer10 mm

bitumen content by weight14 to 17%

Practical Notes

Strict temperature control is critical during heating; overheating the mastic above 200°C degrades the bitumen and compromises waterproofing properties.

The substrate must be completely dry, clean, and primed before the application of bitumen mastic to ensure proper adhesion.

For roofing, laying is typically done in panels and often finished with sand or reflective coatings to prevent UV degradation.