Which terrace flooring heats up the least under sunlight?
The heating of terrace flooring depends on the material’s physical properties. A key factor is the specific heat capacity, which indicates how much energy is required to raise the temperature of 1 kg of material by 1 K. For instance, wood has about 1.7 kJ/(kg·K) and rubber around 1.6 kJ/(kg·K), whereas concrete and marble are only about 0.88 and 0.8 kJ/(kg·K) respectively. This means that with the same energy input, a terrace floor made of concrete or marble will become twice as warm as one made of rubber or wood.
Another important factor is thermal conductivity (λ), which determines how quickly heat penetrates the material. Rubber conducts heat relatively slowly at about 0.16 W/(m·K), whereas marble reaches about 2.8 W/(m·K). Mineral-based floorings such as tiles, natural stone, or plastic (WPC) heat up faster and retain heat longer.
Although under clear skies with all-day sunlight all floor coverings warm up, the surface of a floor covering made of granulate rubber remains significantly cooler thanks to its moderate heating. PU-bound granulate rubber flooring therefore not only offers economic and aesthetic benefits but also provides a pleasantly cool climate in summer.