Hasan Rizvi, CICO Technologies Limited, New Delhi.
Waterproofing is considered to be an important part in modern construction. The word Waterproofing' may be a misnomer as it is virtually impossible to provide absolute exclusion of water or moisture from a masonry/concrete structure. The process is basically an attempt to exclude maximum amount of water or moisture from a structure.
Waterproofing is essentially required where there is hydrostatic head of water to be resisted or where unusually dry conditions must be maintained. On the other hand damp proofing maybe defined as the treatment to retard the passage of water with application of suitable treatment methodology coating or integral waterproofing compounds.
The basic causes of defects in buildings are due to usage of excess water (high w/c/ ratio), by excess water we mean that, adding more water than required for hydration. This leads to formation of capillaries, pores, gel pores through which water can penetrate into the structure thus endangering the durability of the structure.
Concrete possesses a pores and capillaries and in this respect, it is fundamentally different from metal. The capillary and pore structure allows water under pressure to pass slowly through the material. Concrete subject to chemically polluted environment also gets deteriorated and damaged. It is here where polymer technology can be advantageously utilized to provide protection against the attack by water under pressure, acid and alkalis and chemically polluted environment.