What is the acceptable setting time when using these compounds?

The initial setting time must be at least 30 minutes, and the final setting time must not exceed 600 minutes.

Does the addition of waterproofing compound reduce compressive strength?

No, per the standard, the compound must not adversely affect the 3-day and 7-day compressive strength of the concrete or mortar compared to a reference mix.

How is the permeability of the waterproofed mortar evaluated?

It is tested by comparing percolation against a plain standard mortar specimen. The percolation of the treated specimen should be less than 50% of the plain specimen.

IS 2645

: 1975

Integral Cement Waterproofing Compounds - Specification

SupersededFrequently UsedSpecificationMaterials Science · Waterproofing and Damp Proofing

Superseded by IS 2645:2003

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This standard lays down the physical requirements, sampling, and testing methods for integral cement waterproofing compounds added to cement mortar and concrete to minimize water penetration.

Specified requirements for integral cement waterproofing compounds before the 2003 revision.

Quick Reference Values

Initial setting time≥ 30 minutes

Final setting time≤ 600 minutes

Maximum test dosage3% by weight of cement

Water permeability (percolation)< 50% of the plain reference specimen

Practical Notes

Integral waterproofing compounds are not a substitute for good concrete practices; proper w/c ratio, compaction, and curing remain critical for impermeability.

Liquid compounds should be mixed with the gauging water, whereas powder compounds should be uniformly dry-mixed with cement before adding water.

Always adhere strictly to the manufacturer's recommended dosage; overdosing can severely retard setting time and reduce compressive strength.