New green roof lab
Insufficient tests and standards for the popular green roofs. A new lab at Ballerup Campus aims to remedy this.
The number of square metres of green roofing has seen a fivefold increase since 2013— from 39,000 to 197,000 m2. Nevertheless, there is no standardization within the field, which is why a team of lecturers and students have teamed up with two green roofing suppliers to establish a laboratory at DTU Ballerup Campus.
“Engineers, contractors, and consultants often adhere to guidelines and norms in connection with restoration or new builds. We thought that there had to be a standardized approach to green roofing in Denmark—but it seems not. We therefore ran into a lot of questions we couldn’t answer. We want to address this problem—and on the back of a fantastic collaboration with the two supply companies, we have now established an outdoor laboratory for green roofs,” says Associate Professor Jesper Molin, who is a lecturer on DTU’s BEng programme and co-responsible for the project.
The lab consists of a number of test and demonstration projects run by a group of students. Among other things, they examine the roofs’ effect on roof structure, indoor humidity, insulation, and evaporation. However, the students sometimes find working without fixed guidelines slightly challenging.
A variety of roof systems
“The students are really challenged. Running the laboratory requires that they think outside the box. Fortunately, they’re curious and fast learners who have already started to think green roofs into other projects,” says Jesper Molin.
For the company Byggros, the vision for the collaboration is to establish a national green roof test centre. Here, the different solutions will be on show for consultants and clients, who will find it easier to navigate the market, compare solutions, and make decisions based on specific needs.
“As things stand, there are a lot of different green roof systems—each with something different to offer. Some can hold back large amounts of rain, while others promote plant and animal life. The problem is that they’re all grouped together. It’s like comparing pears and bananas, which doesn’t work,” says Torben Hoffmann, technical sales consultant at Byggros.
The lab currently comprises three green roofs: one from each of the two producers—and a ‘neutral’ test roof. Initial findings are expected at the beginning of 2018.
source: Technical University of Denmark