OPTIONS AVAILABLE FOR WATERPROOFING (PART 4)

Various permutations and combinations in specifications can avoid such problems, for example, the following alternatives can be considered:

1.Give a water impermeable coating on the finished surface of IPS – Though this method can prove effective on a short-term basis, may create problems subsequently. It is observed that the coatings based on pure solvent-based polymers, though effective do not function for a larger duration due to its requirement for a thoroughly clean and dry surface. From an economic point of view also these coatings turn to be fairly expensive and basically being a costly commodity, cannot be given in a bigger thickness. These coatings also need to be taken care of for the abuse of UV rays, which involves improvising the formulations knowledgeably with proper UV-absorbent chemical inputs.


2.In order to take care of the above shortcomings, these days, polymeric cementitious coatings are more preferred the world over. These systems have better adhesion to the surfaces and can tolerate to an extent deficiency of the surface like slight wetness and micro dusting etc. The thickness of these coatings also is 8 to 10 times more than pure polymer coatings. However, in this type also, one needs to select the polymer judiciously so that the UV interaction and disintegration due to the same can be avoided.





Though the systems based on the comatrix of polymer and cement are more preferred due to its composite properties like adhesion, waterproofing, flexibility, resistance to UV rays, and improved resistance to wear and tear, a discerning specifier has to bear in mind that after all this system is a film and it is quite possible that due to any physical damage to the concrete surface underneath the coating, the coating itself can get damaged. However, by and large for inaccessible RCC slabs or terrace above, treatment is proved to be very useful and effective even in high rainfall areas like coastal regions or mountain ranges.

3.Another practical approach adopted is to incorporate these water-based polymers in the IPS itself. This increases the water impermeability of the IPS and at the same time decreases the extent of shrinkage cracks due to increase in the flexural strength of the matrix. Additionally, the use of polymers in cement concrete/ mortar is found to increase the adhesion of the concrete mortar to the surface. This integral addition of polymer in mortar is very useful and benefi