Temperature regime of planted roofs compared with conventional roofing systems

This paper analyses the temperature regime of an existing green roof and a sod roof, compared with a modified bituminous membrane roof and a steel sheet roof. The measurement period was from June 2004 to December 2007 at three different measurement locations. Results are given both seasonally and daily; indexes to characterize the effects of the temperature of planted roofs are also proposed. In summer, temperatures under both the green roof (100 mm) and the sod roof (150 mm) showed a similar temperature run; undesirable higher temperatures on the surfaces did not cause a notable increase in temperature under the substrate layers. The difference between the temperature amplitude under the substrate layers of the planted roofs and the surfaces of the conventional roofs was on average 20 °C. In autumn and spring, the sod roof's soil layer showed higher temperatures and lower amplitude than the green roof's substrate layer, which cooled more. In winter, temperatures under the substrate layers of the planted roofs were higher than the surfaces of the conventional roofs; average amplitude was 1 °C and 7-8 °C, respectively.