“Cool roofing”: what is this method of cooling buildings through the roofs?

What about painting your roof white? This practice, known as “cool roofing”, is becoming more and more common and has many advantages: cooling the home, a long roof life… And of course significant energy savings.

Painting the roof of a building white to reduce heat. That said, it seems child’s play. But have to think about it for a while! This method, known as “cool roofing”, is far from new, but is gaining traction in France as heat waves increase in frequency and intensity. According to a recent BVA survey conducted for the online real estate valuation tool Drimki, 55% of French women and men consider energy renovation of buildings a priority.

Cool roofing is widely used in the United States and consists of applying reflective paint, that is, white paint that allows the sun’s rays to be returned to the sky. Thanks to this “albedo effect”, the roof absorbs less heat, which at the same time ensures that the habitat that shelters it keeps cool. And for good reason: about 30% of buildings’ energy leaks come from their roofs.

A white paint also protects the roof, as it protects against possible damage from overheating. The cool roofing also has a significant ecological impact, as it also allows significant energy savings. This means you no longer have to press the air conditioning button all the way! The warm climate countries of Southern Europe have understood this well.

In the Cyclades, the roofs of the famous whitewashed houses that hang from the cliffs also have a white coating. According to green roof expert Geoff Smith of the University of Sydney, quoted by the newspaper the guard, a white roof reflects about 85% of the sunlight that falls on it. Which significantly reduces the heat when the thermometer is around 40 degrees.

In France, the trend of cool roofing is gaining momentum. Some start-ups have specialized exclusively in the sale of reflective paints, such as Cool Roof or Energycool. And the offer is not only interesting for private individuals: the Carrefour brand from Nîmes has painted white under its solar panels installed on the roof. Just like the E.Leclerc store in Quimper, in Finistère (Brittany), which claims to have saved 20,000 euros in electricity costs thanks to this method.

But reflective paint isn’t the only way to practice cool roofing. A green roof has similar effects in terms of thermal insulation, as the plants will form a sort of protective screen against the sun’s rays.

(ETX Daily Up)

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