With the recent rains from the active Northeast monsoon in South India, it is a time for cozy indoors, steaming cups of chai and hot pakoras! But rains are also a time when Indian homes face multiple issue; some can be prevented with basic mindfulness while some become expensive due to ignorance during the construction of the house.
Common Issues Due to Excess Water
One of the most common issues is the fact that ceilings and external walls painted just a season or two ago start showing peeling, bubbling, or damp patches. The most pressing one of them all are the terrace/balcony leakages. Other problems include water seepage through walls, mould growth, swelling and jamming of wooden doors and windows, clogged drainage, and electrical short circuits caused by moisture ingress.
This is caused by several issues. Small cracks which develop with time due to expansion and contraction of the flooring material, gaps in the tile joints, and the most ignored but very important one – blocked drainage points. Quite often, what appears as a small damp patch inside the house actually originates somewhere else. It normally arises due to an untreated terrace, a crack in an external wall, failed waterproofing below balcony tiles, an inadequately sealed window or even a blocked rainwater outlet.
Pre Monsoon Checks
Most of these issues are preventable. It is recommended that monsoon preparation should begin much before the monsoon, rather than after the first leak appears. Minor observations need to be acted upon. Cracks can be repaired, drains cleared, terrace slopes can be checked and waterproofing inspected well in advance. Once moisture has travelled into the wall, we are no longer simply repairing a surface; we are dealing with layers of plaster, putty, paint and sometimes mould as well.
Homeowners should systematically inspect several critical zones. Check roofs and terraces for standing water, cracked parapet plaster, and damaged waterproof coatings. Inspect balconies to ensure drainage slopes are clear. Check windows and doors for perimeter silicone sealants to prevent driven rain from entering. Around windows, look closely at the junction between the frame and masonry. Fenestration systems have improved enormously, but even a very good window can leak if the perimeter sealing or silicone has deteriorated.
This preparation is ideally done few months before the monsoon. Waterproofing compounds, sealants and repairs need dry conditions and adequate curing time. It also gives us an opportunity to test whether the source of leakage has actually been plugged before the heavy rain arrives.
Water Proofing Methods Today
Waterproofing has become much more sophisticated than the yesteryears. Earlier, we relied heavily on cementitious treatments or brick-bat coba. One of the biggest improvements is flexibility. Buildings expand and contract with temperature, and very rigid treatments can eventually crack. Newer elastomeric and PU systems are designed to accommodate a degree of movement and bridge fine cracks. Tile technology has improved too. On balconies and terraces, good-quality tile adhesives, epoxy grouts and properly treated joints reduce the possibility of water penetrating through the finished surface. But tiles and epoxy grout should not be treated as a substitute for waterproofing beneath them.
One Size Does Not Fit All
Waterproofing solutions depend on the surface being treated and according to where the water is coming from. What matters as much as the material is detailing. Junctions between the floor and wall, drain outlets, pipe penetrations, parapets and expansion joints are often where waterproofing fails. For terraces, liquid-applied acrylic or elastomeric membranes are useful because they create a continuous surface without joints. There are also crystalline treatments that penetrate the pores and capillaries of concrete and react within it rather than simply sitting as a coating on top. These can be useful for RCC slabs, basements and water-retaining structures.
Cementitious coatings suit bathrooms, tanks and relatively protected surfaces; acrylic or elastomeric coatings work well for sound external walls and terraces needing periodic renewal. PU membranes are particularly useful for balconies, terraces and areas with complex detailing because they form a seamless, flexible layer. APP/SBS membranes are suited to larger exposed terraces, while EPDM is a premium choice for long-term protection. Selection should always follow a site inspection—not simply the cheapest quote. For internal damp walls, there are waterproofing base coats and moisture-resistant putties that can be applied before the final paint system. But waterproof paint cannot compensate for an unresolved leak. First identify and stop the source of water ingress and allow the wall to dry. Only then should the damaged plaster, putty and paint layers be restored.
Modern Systems
Modern systems cater specifically to the distinct stresses different parts of a house face:
- Liquid Polyurethane (PU) Membranes: Highly elastic, UV-stable liquid rubber that cures into a seamless layer. It handles thermal expansion effortlessly, making it the gold standard for exposed terraces, podiums, and roof gardens.
- Polyurea Spray Coatings: An ultra-fast-curing, industrial-grade coating applied with specialised spray rigs. It sets within seconds and creates an almost indestructible waterproof barrier.
- Crystalline Waterproofing: Instead of creating a surface barrier, this chemical powder penetrates deep into concrete pores. When it meets moisture, it sprouts insoluble micro-crystals that permanently block water pathways from within. It’s perfect for water tanks, basements, and retaining walls.
- Elastomeric exterior coatings are particularly useful because they combine weather protection with a certain amount of crack-bridging ability. Some branded systems now offer warranties of 5–10 years or more when the complete prescribed system is used. Asian Paints, for instance, lists a glass-fibre-reinforced elastomeric membrane for terraces and exterior walls with a 10-year waterproofing warranty under specified application conditions.
Read more about this in my article in The Hindu Property Plus.
