Man's Rs 850 roof trick keeps homes cooler and slashes AC bills during heatwave
With temperatures crossing 44°C in several parts of India, a man claimed his low-cost roof treatment can help keep homes significantly cooler.
As large parts of India continue to grapple with a punishing heatwave, a video of a man demonstrating a low-cost cooling method that he claimed can lower roof temperatures by up to 15 degrees has gone viral on social media.
In the video shared by X user Dinesh K Sen, the person filming was rather surprised upon seeing the man standing barefoot on a rooftop despite the outdoor temperature touching 44°C.
"Let me show you something remarkable. Even in 44°C heat, you're standing barefoot on this roof. What's the secret," he asked the man, identified as Ritesh.
"The sun is blazing, but my roof is cool. This isn't a miracle - it's science. I'm standing here completely barefoot," Ritesh replied, pointing to his watch, which showed 4:15 pm, with the temperature hovering at 44°C.
When asked how he managed it, Ritesh explained that he coated the roof with a mixture of a few materials that helped reduce heat absorption.
The treatment, Ritesh said, lowered the roof's temperature by around 15 degrees, bringing it down to about 28-30 degrees Celsius even during peak afternoon heat.
"You won't need to rely as much on coolers or air conditioners. Even a fan will start giving cooler air," he said.
Ritesh then detailed the materials he used. He bought 20 kg of lump lime (commonly known as chuna), for around Rs 350, 5 kg of Fevicol DDL binder and 500 gms of a waterproofing compound called Universal Repair Polymer (URP), which cost about Rs 200.
Explaining the process, he said the lime should be soaked overnight in about 50 litres of water. Once the mixture cools, the binder and waterproofing compound are added and mixed thoroughly before being applied to the rooftop.
He recommended applying at least one coat, adding that a second coat could be used if the material remained.
When asked how much it would cost to treat a 1,000-square-foot roof, Ritesh estimated the expense at around Rs 800 – Rs 850.
"It's very inexpensive. The temperature outside is 44°C, while the roof temperature is around 30°C, and it's 4:15 in the afternoon under direct sunlight," he said.
Watch the video here:
The video triggered several reactions from social media users, many of whom pointed to the science behind reflective roof coatings.
"White reflective coating is real science. It reflects most of the sun's heat instead of absorbing it. Proper cool-roof coatings, or even a good lime-and-binder mix, can reduce roof surface temperatures by 10-20 degrees Celsius and lower indoor temperatures by several degrees," one user commented.
Another user suggested placing plants and pots on rooftops, saying soil and vegetation can help absorb heat and keep temperatures lower.
"These days, desi innovation is no less than technology. If roof cooling is done properly, the load on air conditioners can be reduced significantly," another wrote.
One user recalled advice from a mason who had worked in Chennai and said similar lime-based roof treatments were known to reduce heat considerably.
Others noted that reflective lime coatings and cool-roof paints have long been used as a simple way to reduce heat absorption and improve indoor comfort during extreme summer temperatures.
As large parts of India continue to grapple with a punishing heatwave, a video of a man demonstrating a low-cost cooling method that he claimed can lower roof temperatures by up to 15 degrees has gone viral on social media.
In the video shared by X user Dinesh K Sen, the person filming was rather surprised upon seeing the man standing barefoot on a rooftop despite the outdoor temperature touching 44°C.
"Let me show you something remarkable. Even in 44°C heat, you're standing barefoot on this roof. What's the secret," he asked the man, identified as Ritesh.
"The sun is blazing, but my roof is cool. This isn't a miracle - it's science. I'm standing here completely barefoot," Ritesh replied, pointing to his watch, which showed 4:15 pm, with the temperature hovering at 44°C.
When asked how he managed it, Ritesh explained that he coated the roof with a mixture of a few materials that helped reduce heat absorption.
The treatment, Ritesh said, lowered the roof's temperature by around 15 degrees, bringing it down to about 28-30 degrees Celsius even during peak afternoon heat.
"You won't need to rely as much on coolers or air conditioners. Even a fan will start giving cooler air," he said.
Ritesh then detailed the materials he used. He bought 20 kg of lump lime (commonly known as chuna), for around Rs 350, 5 kg of Fevicol DDL binder and 500 gms of a waterproofing compound called Universal Repair Polymer (URP), which cost about Rs 200.
Explaining the process, he said the lime should be soaked overnight in about 50 litres of water. Once the mixture cools, the binder and waterproofing compound are added and mixed thoroughly before being applied to the rooftop.
He recommended applying at least one coat, adding that a second coat could be used if the material remained.
When asked how much it would cost to treat a 1,000-square-foot roof, Ritesh estimated the expense at around Rs 800 – Rs 850.
"It's very inexpensive. The temperature outside is 44°C, while the roof temperature is around 30°C, and it's 4:15 in the afternoon under direct sunlight," he said.
Watch the video here:
The video triggered several reactions from social media users, many of whom pointed to the science behind reflective roof coatings.
"White reflective coating is real science. It reflects most of the sun's heat instead of absorbing it. Proper cool-roof coatings, or even a good lime-and-binder mix, can reduce roof surface temperatures by 10-20 degrees Celsius and lower indoor temperatures by several degrees," one user commented.
Another user suggested placing plants and pots on rooftops, saying soil and vegetation can help absorb heat and keep temperatures lower.
"These days, desi innovation is no less than technology. If roof cooling is done properly, the load on air conditioners can be reduced significantly," another wrote.
One user recalled advice from a mason who had worked in Chennai and said similar lime-based roof treatments were known to reduce heat considerably.
Others noted that reflective lime coatings and cool-roof paints have long been used as a simple way to reduce heat absorption and improve indoor comfort during extreme summer temperatures.
