With over 26 years of technical experience across construction chemicals, structural rehabilitation and waterproofing consultancy, Tushar B. Munshi brings deep insight into why waterproofing must be treated as a specialised discipline, and not as a last-minute site activity. In this candid interview, he explains the causes of leakage, evolving innovations, and why India urgently needs trained professionals in waterproofing.
Q How important is waterproofing for a structure?
Waterproofing goes far beyond preventing water from entering a building. It plays a decisive role in preventing reinforcement corrosion, maintaining the structural integrity of the building, preserving aesthetics, and avoiding health hazards caused by dampness and fungal growth. In the long run, it saves homeowners and developers from significant financial losses related to repairs and rehabilitation. In many ways, waterproofing is the foundation of a building’s durability.
Q What causes leakages in buildings?
Most leakages stem from identifiable weaknesses within the structure.
These include natural porosity in concrete, cracks of various sizes, construction or pour joints, tie-rod holes, honeycombing in concrete, gaps between pipes and core cuts, weak interfaces where two dissimilar materials meet—such as windows fixed against masonry or glass set in metal—and faulty plumbing joints. Each of these creates a potential path for water to enter and travel through the structure.
Q What does it take to deliver an effective waterproofing solution?
The golden rule is simple: treat the source. Once the origin of leakage is identified and addressed, a reliable waterproofing system can be designed. This begins with a detailed study
of site conditions, which vary from project to project. Selecting the correct product is equally critical—since no single product fits all problems. Proper surface preparation, including grinding, cleaning, sealing cracks and rectifying concrete defects, is essential for any system to function. Finally, waterproofing must always be approached as a system—a combination of surface preparation, the right product, quality application, suitable overlays and efficient drainage. It is this integrated system that guarantees long-term success.
Q How is waterproofing evolving as construction technology becomes faster?
Speed is now central to construction economics. With precast systems, modular concrete sections, prefabricated elements, and aluminium formwork becoming common, waterproofing must evolve alongside these technologies. This has led to innovations such as mechanised surface preparation, spray-applied coatings and high-performance products designed to cure faster without compromising quality. Modern methods also introduce new leakage risks—like precast joints, tie-rod holes and strip joints in aluminium formwork—which require specialised sealing solutions. Today, waterproofing must be both technologically advanced and aligned with the accelerated pace of modern construction.
Q How does a waterproofing consultant add value during construction?
A waterproofing consultant brings focussed technical oversight across design, specification and execution. They review drawings, recommend systems suited to site conditions, and align waterproofing with other services such as structural elements, plumbing and HVAC. In the rush to speed up construction, waterproofing often receives inadequate attention; a consultant ensures that doesn’t happen. By monitoring product selection, system design and execution, they safeguard the project’s long-term performance. Essentially, the consultant acts as the project’s dedicated custodian for waterproofing excellence.
Q What makes basement waterproofing particularly challenging in urban areas?
Urban projects often require deep basements for parking, but redevelopment sites generally have very tight working spaces. These constraints make basement waterproofing complex. Over the last 23 years, we have developed solutions that allow positive-side waterproofing even in confined environments—avoiding the need for negative-side treatments, which can accelerate corrosion of the reinforcement. Because soil layers, water tables and urban site conditions vary dramatically from location to location, every basement requires a customised design, product specification and treatment strategy.
Q What latest innovations has your company introduced?
One major innovation is our specially developed gunnable cementitious waterproof mortar, designed to fill and seal tie holes and strip joints in aluminium formwork. These penetrations run through the entire concrete thickness, and conventional grouts often fail to seal them completely. Our ready-to-use mortar, which can be applied using a sealant gun, ensures full-depth sealing and has been thoroughly tested over the past two years by several leading construction companies. Additionally, we have upgraded our crystallisation systems, bonding agents and liquid-applied membranes to align with faster construction cycles and evolving environmental demands.
Q Is there a standard approach to maintenance waterproofing?
Currently, maintenance waterproofing in India remains largely unorganised. It is dominated by local plumbers, painters and small contractors who may not be fully trained in product selection, application techniques or standard operating procedures. While retail brands attempt to train labour, overall standardisation remains inadequate. As consultants, we are trying to bring structure into this space by introducing solution charts, promoting correct preparation methods, outlining proper application procedures and implementing checklists for each stage of work. We are also investing in predictive technologies—IoT, sensors, data analytics and AI—to make waterproofing measurable, trackable and proactive in the future.
Q How important is training in waterproofing, and what initiatives are you leading?
Training is absolutely essential. Waterproofing demands technical knowledge, hands-on skill and continuous upskilling, especially as products and technologies evolve. Both classroom sessions and on-site training are crucial to ensure consistent, durable results. As the Training Head of the Waterproofers Association of India (WAI), I oversee nationwide programmes aimed at professionalising the waterproofing community. At our office, we have a dedicated training facility where we educate stakeholders across the ecosystem. Our mission is clear: to build a technically strong, skilled community of waterproofing professionals and elevate the discipline to a respected and essential branch of construction.
