Concerns and challenges for contractors
Kunjan Popat: India’s famous Himalayas, while having the most attractive regions in the world, experience a lot of humidity because of the low temperature. The waterproofing chemicals used in the building in these areas must be able to resist the extreme low temperatures and be freeze-thaw resistant. WAI recently organised a conference at Kufri, Shimla, during which many waterproofing challenges and concerns in hilly regions were discussed.
The right people should be approached for waterproofing. I believe that architects have no control over waterproofing, and hence, waterproofing should be made a part of building bylaws and codes. However, both the architects and the contractors should be aware of the materials in the market. They don’t realize that freeze-thaw cycles are major problems for waterproofing in hilly regions.
MS Sudish: Waterproofing at high altitude areas has challenges such as slow setting time of waterproofing products; cracking of water proofing membranes; reduced flexibility of waterproofing membrane making it susceptible to cracking; the harsh climate requires proper planning and execution, and also keeping in mind the closure of access during winter season; humidity tolerance of waterproofing which is generally 5% to 10%, could range between 70% to 80% at higher altitudes.
Availability of waterproofing chemicals
Kunjan Popat: No doubt, there are a lot of problems due to differential temperatures, and certain chemicals don’t work well in low temperatures. So, one must know how a chemical would behave at say 10, 12, or 13 degrees, etc. and also know how to apply them. However, there are special chemicals and plasticizes available for low temperatures, but there is not enough awareness about them by the end-users.
Ramendra Bahadur Sinha: We have some world-class manufacturers whose products can be used even below -20 degree. Now, Agrani has also entered manufacturing of waterproofing products.
MS Sudish: Some waterproofing solutions for sub-zero temperatures, which are available in India are:
- SBS (styrene-butadiene-styrene) modified torch on membranes which offers cold flexibility of -20oC
- Polyurea with moisture insensitive primer
- Polyvinyl chloride (PVC) / Thermoplastic polyolefin (TPO) / Ethylene propylene diene monomer rubber (EPDM) membranes laid loosely with random mechanical anchoring to surface.
Kunjan Popat: There is minimal standardization when it comes to such a major segment like waterproofing. The Waterproofing Association of India has been working on developing the guidelines, which should be made mandatory for builders. Better materials have come in the industry since the last 30 years, but their adoption is lagging due to this issue.
Ramendra Bahadur Sinha: Guidelines could vary from project to project, and the specifications of the work suggested by the client, consultant, or the experts for a particular project, and considering the geological factors. However, a minimum qualification should be made mandatory for the material manufacturer as well as the applicator.
MS Sudish: Even though waterproofing contributes 3% to 4% of construction cost, it is the most sensitive activity of construction. Hence, due respect and consideration should be given to waterproofing right from the building’s design stage. I would like to suggest the following guidelines for effective waterproofing:
- Product must be selected according to the type of construction, the strata, usage and climatic conditions of the location.
- Selection of applicator
- Surface must be prepared before application of waterproofing products. The surface must be clean, free from any chemicals or oils, and there should be no cracks or spalling of concrete.
- Proper surface protection after waterproofing
- Attention to detailing especially in changes of direction and termination.
- Proper treatment of construction joints, tie rod holes, bore packing and expansion joints.
MS Sudish: In waterproofing, cost shouldn’t be the first priority. Any dilution in waterproofing will result in spending a huge amount of money towards repair and restoration. In addition, inconvenience, and consequential damages, including revenue loss due to faulty waterproofing should be considered before selecting the waterproofing system. Selection of waterproofing system should be done based on design requirements and design parameters rather than the manufacturer, product, or previous experiences.
Kunjan Popat: While saving money during construction, builders should note that it takes 10 times the cost to tend to waterproofing issues that may erupt in the future, compared to waterproofing done while constructing the building. Not only loss in expenses, but this can spoil the reputation of the builder as well.
Ramendra Bahadur Sinha: Volatility in international markets is causing an increase in raw material rates, so the cost of projects is also crossing the estimated budget. Such fluctuations also impact the client, which may reflect in delays in payment etc. As a cost conscious market, India still depends on market conditions which are very volatile currently.