What are the Challenges in waterproofing of Structures?

To me, the biggest challange is the lack of understanding what we want to achieve and the root causes of failure. Just using some chemicals blindly is not going to get your structure (I assume an enclosed space here) waterproofed. One needs to identify the plausible sources of breach and address these individually. I have seen water flowing through electrical conduits laid in wall chases because they were not properly sealed. I have seen water leak through gaps between the wall and door / window frames and also through gaps between frames and glazing, through cracks at ceiling and wall junctions, through gaps between the flooring and the drain pipe. Every such occurance needs to be thoroughly studied and and appropriate solution arrived at. No amount of tar felting or membrane waterproofing is going to stop water from seeping in if the roof slopes are not properly made to drain the water completely through rain water pipes and water is allowed to form puddles on the roof. No amount of waterproofing will stop water leakage through walls permanently if the walls are not made sound and impervious through proper construction. In most builder built buildings, I have been able to see daylight through the joints in the bricks (including hollow blocks, for which the consequences are worse). Sound construction practice is the starting point for sound waterproofing, rest all come later.

Waterproofing is an activity in the domain of civil engineering, and it involves structures. It can thus be very helpful to have a good knowledge of civil engineering and structures. Thus, when chemists and material scientists develop chemicals and systems of waterproofing , they are likely to overlook fine points in civil-structural construction engineering, and the technology for waterproofing may not be appropriate. This is particularly so as most often technologies are first developed, and later avenues are sought to apply the technology. The best results are possible when technologies are developed to solve problems, and not the other way round.

Every work site has a character of its own, requiring improvisation. Though a particular waterproofing chemical and a particular system will be employed as the basic treatment, local conditions frequently require for a successful waterproofing treatment that certain modifications are made to the implementation procedure or that a different chemical and a different system be employed locally as a stand-alone or as an additional treatment. A failure to make necessary improvisation may lead to a failure of the waterproofing treatment.

CEMENT : In India we find mostly OPC,PPC,PSC.  MUCH OF THE CONSTRUCTION FATERNITY KNOW THAT PPC IS MORE CORROSION RESISTANT, CHEMICAL RESISTANT AND PSC IS STILL BETTER THAN PPC INTHESE ASPECTS. aS SUCH PSC IS RECOMMENDED FOR PORTS ALSO.

uSAGE OF SUTIABLE SAND, AND USAGE OF GOOD BLUE CHIPS  BETTER WORKMANSHIP CAN GIVE GOOD FINISHING PRODUCTS. AND CAN LEAD TO WATERPROOFING CONSTRUCTIONS.

BETTER MASONARY PRACTICES CAN ALSO CONTRIBUTE A GREAT DEAL IN THIS MATTER.