What are the main types of membranes covered by IS 14777?

Type 1 (with polyester mat reinforcement) and Type 2 (with glass fibre mat reinforcement), each available in Grade A and B based on performance.

What is the difference between polyester (Type 1) and glass fibre (Type 2) reinforcement?

Polyester (Type 1) offers higher tensile strength and elongation, making it more robust and suitable for demanding applications. Glass fibre (Type 2) provides excellent dimensional stability.

What is the test for heat resistance?

The softening point test (using Ring and Ball apparatus as per IS 1205) is used. For APP membranes, it is typically required to be above 150°C.

Does this code specify how to install the membrane?

No, IS 14777 is a material specification. Application and installation procedures are covered in codes of practice like IS 1346 and manufacturer's guidelines.

IS 14777

: 2000

Bitumen membrane for waterproofing (modified bitumen membranes)

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This standard specifies the requirements for factory-manufactured polymer modified bitumen waterproofing membranes. It covers membranes reinforced with polyester (Type 1) or glass fibre (Type 2), detailing material properties, physical requirements like tensile strength and flexibility, and prescribed testing methods.

Specifies requirements for modified bitumen membranes for waterproofing applications.

Quick Reference Values

Minimum longitudinal tensile strength (Type 1, Grade A)650 N/50 mm

Minimum longitudinal elongation at break (Type 1, Grade A)40 %

Maximum water absorption (all types)1.0 % by mass

Low temperature flexibility (no cracking at)0 °C

Minimum puncture resistance (Type 1)150 N

Minimum softening point (for APP membranes)150 °C

Practical Notes

APP modified membranes are generally preferred for high temperature and UV exposed areas like roofs, while SBS membranes offer better flexibility for areas with structural movement or in cold climates.

Proper surface preparation, including the application of a compatible bitumen primer, is critical for achieving a monolithic and effective waterproofing system.

Ensure membrane thickness is specified and verified as per project requirements (e.g., 3mm or 4mm), as this standard covers properties but not application-specific thickness selection.