We test green roofs

News, 08/02/2019

The CTU University Center for Energy Efficient Buildings at its headquarters in Buštěhrad has been testing various types of vegetation roofs for a long time in cooperation with the company Metrostav. The aim is to assess different compositions of green roofs with regard to the reliability of their function, maintenance requirements and other properties. The knowledge gained can significantly contribute to energy-saving cooling of buildings and their surroundings during hot days.

Testing takes place on a total of 24 test areas built on the roof of the UCEEB building in Buštěhrad. The goal of the construction, completed in June 2018, was to ensure the widest possible spectrum of compositions of extensive green roofs and planted vegetation consisting of a mixture of drought-loving plants. Extensive compositions are characterized by low requirements for the strength of the formations. Different types of available substrates are tested, which are combined with a wide range of drainage or hydroaccumulation layers in the subsoil. The vegetation of the roofs consists primarily of sedges and sedges (see photos below), which in some variants are complemented by fescue and herbs. Apart from them, limestone carpets are tested.

All test areas are equipped with autonomous microclimate stations measuring humidity and temperature inside the experimental formations. The weather station located on the roof of the UCEEB building provides data on the external environment (temperature, humidity and air pressure, wind direction and strength, incident and reflected short-wave and long-wave radiation). Scientists also record the development of vegetation and the appearance of unwanted weeds. The processed data obtained during the first and second stages of the project from June to December 2018 are currently available. The completion and final evaluation of the tests is scheduled for the end of 2021.
Vegetative roof formed by a mixture of drought-loving plants.