As summer temperatures continue to climb across India, a low-cost rooftop cooling method has captured significant attention online. A viral video circulating on social media claims that a do-it-yourself (DIY) roof coating, costing less than ₹800, can dramatically reduce roof temperatures by as much as 15°C, offering considerable relief even when outdoor temperatures soar past 45°C.
A Budget-Friendly Alternative to Air Conditioning
With air conditioners becoming increasingly expensive to purchase and operate, many homeowners are seeking more economical ways to combat the heat. Dinesh K Sen, an X user, demonstrated this reflective coating technique, arguing it provides a viable alternative to investing ₹20,000-₹30,000 in an AC unit. The principle is simple: applying a reflective layer to the rooftop reduces heat absorption, keeping indoor spaces cooler.
What You Need for the DIY Cooling Mix
According to the viral demonstration, the cooling mixture requires readily available materials:
- 20 kg of white lime powder (chuna)
- Approximately 50 litres of water
- Fevicol binder (around 5 kg)
- A waterproofing compound such as Dr Fixit URP (Universal Repair Polymer)
The total estimated cost for these materials reportedly ranges from ₹800 to ₹850, making it an accessible solution for many households.
Application Process for Reflective Roof Coating
The preparation for this DIY roof cooling solution begins by mixing the white lime powder with about 50 litres of water, allowing it to dissolve completely overnight. The following day, approximately 5 kg of Fevicol binder is added to enhance the mixture's adhesion to the roof surface. Subsequently, a waterproofing compound like Dr Fixit URP is incorporated to improve durability and water resistance.
Once all ingredients are thoroughly stirred to achieve a smooth, uniform consistency, the roof surface must be cleaned meticulously to remove any dust, dirt, or loose particles. The prepared coating is then applied evenly across the roof, typically using brushes or rollers, often in multiple layers for optimal coverage. After drying under direct sunlight, the coating forms a bright, reflective white surface designed to deflect solar radiation.
The Science Behind Cool Roof Technology
The effectiveness of this DIY method is rooted in a well-established scientific principle: white and light-colored surfaces reflect a substantial portion of incoming sunlight rather than absorbing it. This reflection helps maintain a cooler roof surface, significantly reducing the amount of heat transferred into the building's interior.
Research into cool-roof technologies consistently supports these findings, showing that reflective coatings can lower roof surface temperatures, enhance indoor thermal comfort, and lead to reduced energy consumption. Studies conducted within India, including pilot projects in schools in Tamil Nadu, have reported measurable indoor temperature reductions of approximately 3-4°C, validating the practical benefits of such applications.