Viral Rs 850 roof coating hack promises relief from scorching heatwave

A low-cost rooftop cooling method demonstrated by a man during India’s ongoing heatwave has gone viral on social media, with claims that it can significantly lower roof temperatures and reduce dependence on air conditioners.

The viral video shows Ritesh standing barefoot on a rooftop despite outdoor temperatures touching 44°C. He explains that a special coating applied on the roof helps keep the surface temperature around 28–30°C during peak afternoon heat.

According to Ritesh, the cooling mixture is prepared using lump lime (chuna), Fevicol DDL binder and a waterproofing compound known as Universal Repair Polymer (URP). He claimed the entire treatment for a 1,000-square-foot rooftop costs roughly Rs 800 to Rs 850.

He explained that the lime is first soaked overnight in water before being mixed with the binder and waterproofing compound. The solution is then applied as a coating on the rooftop surface.

Ritesh said the reflective coating reduces heat absorption and helps keep homes cooler naturally, lowering the need for coolers and air conditioners even during intense summer conditions.

The video sparked widespread discussion online, with many users highlighting the science behind reflective white coatings and cool roof technology.

Several users said lime-based coatings have traditionally been used in many parts of India to reduce indoor temperatures during summer. Others suggested adding rooftop plants and soil layers to further minimise heat absorption.

The viral hack comes as multiple states continue to experience severe heatwave conditions, forcing people to search for affordable and energy-efficient ways to stay cool amid soaring temperatures and rising electricity bills.